Project title:
|Project title: |Cordyline and Phormium: pests, diseases and disorders |
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|Project number: |HNS 171 |
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|Project leader: |Dr Jill England, ADAS |
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|Report: |Final |
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|Previous reports: |None |
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|Key workers: |Dr Jill England (principal investigator, case study) |
| |Dan Drakes (case study) |
| |John Atwood (case study) |
| |Neil Gray (case study) |
| |David Hutchinson (case study) |
| |Dr Charles Lane (FERA) (P&D analysis) |
| |Tricia Giltrap (FERA) (P&D analysis) |
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|Location: |Desk study / survey |
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|Project co-ordinators: |Dr Steve Carter, Fleurie Nursery, Eastergate Nurseries |
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| |David Hooker, Hillier Nurseries Ltd. |
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| |Paul Dyer, Star Plants. |
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|Date commenced: |1 January 2009 |
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|Date completion due: |31 July 2009 |
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|Key words: |Cordyline, Phormium, leaf spot, tip burn, stem rot, crown rot, disease, |
| |physiological disorder, oedema, pest, thrips, aphid, mealybug, two-spotted |
| |spider mite, slugs, snails. |
All information provided to the HDC by ADAS in this report is provided in good faith. As ADAS shall have no control over the use made of such information by the HDC (or any third party who receives information from the HDC) ADAS accepts no responsibility for any such use (except to the extent that ADAS can be shown to have been negligent in supplying such information) and the HDC shall indemnify ADAS against any and all claims arising out of use made by the HDC of such information.
The results and conclusions in this report are based on an investigation conducted over several months. The conditions under which the experiment was carried out and the results obtained have been reported with detail and accuracy. However, because of the biological nature of the work it must be borne in mind that different circumstances and conditions could produce different results. Therefore, care must be taken with interpretation of the results especially if they are used as the basis for commercial product recommendations.
AUTHENTICATION
I declare that this work was done under my supervision according to the procedures described herein and that the report represents a true and accurate record of the results obtained.
Dr J. England
Horticultural consultant
ADAS UK Ltd
Signature .......................................................... Date .................................................
Report authorised by:
Dr T. O’Neill
Horticultural Research Manager
ADAS UK Ltd
Signature .......................................................... Date ................................................
Contents
Grower summary 1
Headline 1
Background and expected deliverables 1
Summary of the project and main conclusions 2
Financial benefits 2
Action points for grower 3
Science section 5
Introduction 5
Methods 6
Literature review 7
Initial survey results 20
Case study results 36
Pest and disease analysis report 51
Discussion 53
Conclusions 58
References 60
Appendices 60
Grower summary
Headline
The most problematic pests, diseases and disorders to affect Cordyline and Phormium cultivars have been identified:
Cordyline: two-spotted spider mite and the undiagnosed disorders: yellow leaf spot syndrome, tip burn and ‘wobble’.
Phormium: Phormium mealybug and two-spotted spider mite.
Background
Recent mild winters and dry summers have created a resurgence of interest in tropical-looking plants, including a range of Cordyline and Phormium cultivars, resulting in increased sales which are of great value to the hardy ornamental nursery stock industry. However, UK growers have reported major problems affecting their production. This study was designed to provide information on the scale of current problems, identify further investigations needed into the causes and the development of production strategies to eliminate them.
The expected deliverables were:
• To provide an overview of the major challenges encountered by Cordyline and Phormium growers.
• To carry out limited sample analysis of Cordyline plants affected with yellow leaf spot syndrome (at the Food and Environmental Research Agency, FERA) to identify any causal agents present.
• To gain an understanding of the husbandry and crop protection techniques currently in use to address these challenges.
• To suggest production strategies and future targeted investigations to enable these problems to be resolved.
Summary
This study involved a review of information from literature, growers and consultants relating to pests, diseases and disorders affecting Cordyline and Phormium production. An initial grower survey, in which 44 Cordyline and Phormium growers participated, provided an overview of the difficulties faced. Case studies targeting eight growers from across the country then provided in-depth information concerning current practice in producing these crops and combating the problems experienced.
Survey results
Problems highlighted as affecting production of quality Cordyline and Phormium were:
Pests
• Phormium mealybug (Balanococcus diminutus) and Cordyline mealybug (Balanococcus cordylinidis).
• Two-spotted spider mite
• Slugs and snails
• Aphids, thrips, tortrix caterpillars, vine weevil and sciarid fly larvae (reported not a serious risk to the crops)
Diseases and disorders
• Yellow leaf spot syndrome / oedema
• Other leaf spots
• Tip burn
• ‘Wobble’ or ‘rock’
• Crown, stem and root rots
Financial benefits
Financial benefits to growers obtained from resolving the issues raised in this report include reduced wastage and increased profit margins for growers, and a premium product for the customer. The results of this survey suggest that by controlling the major issues reported (tip burn, yellow leaf spot syndrome, two-spotted mite and Phormium mealybug) there could be a financial benefit of around £1.8 million each year to the UK horticulture industry.
Action points for growers
A number of the conditions reported require further investigation. However, there are some general action points and respondent comments that may help to improve crop quality.
• Yellow leaf spot syndrome / oedema control: do not over water, provide adequate ventilation and spacing between plants, and where possible increase light intensity during the late winter / early spring when these symptoms tend to develop.
• Leaf spot control: pay attention to water management in terms of application timing and / or method. Avoid wetting leaves during irrigation where possible and apply water early enough to enable leaves to dry off before temperatures drop. Ensure the cause is correctly diagnosed by laboratory analysis so that the appropriate control measures may be applied.
• Phormium mealybug control: Key to controlling Phormium mealybug is to quarantine new stock on arrival and inspect each plant for infestations, taking particular care to look in leaf folds and at the base of the leaves. Infested stock should not be allowed onto the nursery.
• Two-spotted spider mite control: A number of predators are available for control of two-spotted mite including Phytoseiulus persimilis, Amblyseius andersoni, A. californicus, and Feltiella acarisuga, although some growers have reported difficulty in adequately establishing predators in these crops. There are also several acaricides that are approved for use on ornamental plants under protection, including Apollo 50 SC (clofentezine), Masai (tebunenpyrad) and Dynamec (abamectin). Before using any of these acaricides in an IPM programme, their compatibility with any biological control agents being used should be checked with the biological control supplier. The pyrethroids including Gyro (bifenthrin) and Talstar 80 Flo (bifenthrin) are effective but are not IPM-compatible. Experience has shown that the waxy leaves of Phormium make good spray coverage difficult, and the addition of an adjuvant such as Codacide may improve chemical control of two-spotted spider mite.
• Tip burn control: grower experience suggests that careful water management, calcium supplements, foliar feeding, site selection (avoiding a high fluoride level in the water) and temperature control may help to reduce tip burn.
• Wobble or ‘rock’ control: plant Cordyline deeper to encourage lateral root development nearer the base of the trunk to stabiliser plants. Planting depth would vary depending on the maturity of the plant, but the critical point would be to avoid burying the growing tip.
Science section
Introduction
Cordyline australis (New Zealand Cabbage Tree, Agavaceae), native to New Zealand, Australia, India, South America and Polynesia, and Phormium tenax (New Zealand Flax, Phormiaceae, revised from Agavaceae), native to New Zealand, are both monocotyledonous evergreens highly regarded by gardeners for their architectural merit (Armitage et al., 2005; Kelly, 1995).
Recent mild winters and dry summers have created a resurgence of interest in tropical-looking plants, including a range of Cordyline and Phormium cultivars with sales of great value to the hardy ornamental nursery stock (HONS) industry. However UK growers have reported major problems affecting their production; the main objective of this study was to identify the scale and causes of the major pest, disease, virus and environmental factors implicated in causing the production of substandard Cordyline and Phormium crops in UK HONS, and to provide growers with technical advice to enable them to consistently produce crops of premium quality.
Aims of the survey were:
• To produce a review of literature, and information from growers and consultants, relating to pests, diseases and disorders of these crops.
• To provide an overview of the major challenges encountered by Cordyline and Phormium growers.
• To gain an understanding of the husbandry and crop protection techniques currently in use to address these challenges.
• To carry out limited sample analysis of affected plants to identify any causal agents present.
• To suggest future research needs to resolve these challenges and produce best practice guidelines for growers.
Methods
A literature review of pests, diseases and disorders of Cordyline and Phormium and related plants, entailed searches of scientific literature (Scopus and Science Direct), HDC reports and the internet in general. Other horticulture consultants (John Adlam, Dove Associates, Owen Jones (ADAS, retired) and Neil Hellyer, Fargro) were contacted to provide their views on factors adversely affecting production of these crops in the UK.
An initial survey proforma was constructed by Jill England (ADAS) (Appendix 1), approved by the Steve Carter (project coordinator) and Scott Raffle (HDC) and circulated to Hardy Nursery Stock grower members of the HDC in paper format (via the HDC) for completion. Key Cordyline and Phormium producers who had not responded were then contacted by telephone and email to ensure they were aware of the survey and had the opportunity to participate. This survey aimed to gather broad information on the major problems affecting production of Cordyline and Phormium crops grown in the UK, providing information on their scale and causes.
Eight nurseries were selected to take part in an in-depth case study (Appendix 2); these were a geographical cross section of nurseries involved in different stages of production, with and without the major pest, disease and disorder problems to enable a balanced review of the cultural practices being used commercially. A proforma was again constructed by J. England (ADAS) and approved by the project coordinators (Steve Carter and Dave Hooker) and used as a basis for on-site interviews by ADAS consultants (John Atwood, David Hutchinson, Neil Gray, Dan Drakes and Jill England). Chemicals reported within the initial survey and case studies are those noted by growers and do not imply current approval for use under protection within the UK.
Samples of Cordyline affected by yellow leaf spot syndrome were collected during the case studies and submitted to the Central Science Laboratory, York (FERA) for further investigation. They were subjected to analysis for pests, diseases, and viruses, including cellular examinations using a range of modern (PCR, transmission electron microscopy, scanning EM, fatty acid profiling, pyrosequencing etc) and conventional diagnostic techniques.
Literature review
Pests
Several pests have been recorded on Cordyline and Phormium, in particular the Phormium mealybug and two-spotted spider mite, slugs and snails but also aphids and thrips to a lesser degree.
Phormium mealybug (Balanococcus diminutus Leonardi, syn. Trionymus diminutus Leonardi) and Cordyline mealybug (Balanococcus cordylinidis)
The mealybug (including both Phormium and Cordyline) is a member of homoptera, the scale insects, a large group which includes the armoured scales, soft scales and mealybugs with piercing, sucking mouth parts and which are sexually dimorphic (i.e. the male and female are different). Mealybug is reportedly more of a problem on Phormium than Cordyline.
The Phormium mealybug is primarily associated with Phormium tenax J.R. & G. Forst (New Zealand Flax). (Bartlett, 1981). It was first identified in the UK in October 1977 on a consignment of P. tenax ‘Goldspike’ at a nursery in Diss, Norfolk, imported from New Zealand, and from there it quickly spread throughout the UK (Bartlett, 1981). The Phormium mealybug is an important pest for several reasons, including its ability to survive low temperatures, overwintering both inside and outside in many areas of the UK (Buczacki and Harris, 2005).
The Cordyline mealybug is associated with Cordyline australis (G. Forst) Endl. and has not been identified in the UK by FERA at present. Until 1987 Balanococcus cordylinidis was considered to be a subspecies of Balanococcus diminutus. They were separated in 1987 and there remains confusion in the literature. There are morphological differences and laboratory verification would be required to differentiate between the two species (Malumphy, 2009). The glasshouse mealybug (Pseudococcus viburni) is also found associated with Cordyline spp.
Mealybug adult females and nymphs cover themselves in a waxy, mealy substance which insecticides have difficulty penetrating, preventing direct contact with the mealybug (Gavin, 1992). In Phormium, mealybugs secrete themselves deep within the leaf axils. Phormium leaves are covered with a waxy cuticle which prevents or reduces penetration by systemic chemical controls and which it is difficult for insecticides to adhere to.
A number of biological control agents are approved and effective against various mealybug species in the UK, including predators and parasitic wasps. However, the parasitic wasps are effective on specific mealybugs, for example Leptomastix dactylopii is host specific to citrus mealybug and Leptomastix epona is host specific to vine mealybug, and neither would control Phormium mealybug (Copland, 2008).
Another biological control, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), a small coccinellid predatory beetle (ladybird) is effective against all mealybugs and used against pests on crops grown under protection in the UK. It has dark brown wing covers, an orange head and posterior and is around 4 mm long. C. montrouzieri lays yellow eggs among the woolly egg masses produced by female mealybugs, which hatch into white larvae that are covered with wax-like filaments, resembling adult mealybugs. Adults and larvae feed on all developmental stages of the mealybug, and fly in search of new colonies (Koppert, 2007). However, they are largely inactive below 150C, are most effective between 210C and 300C F (BCP Certis, 2006) and have difficulty in getting down into the leaf axils where mealybugs tend to hide (Hellyer, 2008).
Previous projects studying the mealybug Pseudococcus viburni found on UK tomato crops (Croft, 2007; de Courcy Williams, 2002; Morley and Jacobson, 2008) found the most effective Integrated Pest Management (IPM) compatible treatment for control was the selective insect growth regulator buprofezin (Applaud). Applaud has a particularly good effect where plants are covered with fleece for a week to take advantage of the vapour action which then penetrates into the Phormium leaf axils (Hellyer, 2008). However, some resistance has been recorded and also approval of this product has been revoked with a final use date of 30 March 2010 (Pesticides Safety Directorate, 2008). The biological controls investigated within these projects were parasites (Leptomastix epona, Anagyrus pseudococci and Pseudaphycus maculipennis), predatory mites (Hypoaspis miles and H. aculeifer) which were found unsuitable, and a predatory lacewing (Chrysoperla carnea) which required further investigation. Application of the entomopathogenic fungus Verticillium lecanii (Mycotal WP) following Savona provided 100% mortality in some instances, but results were variable. The entomopathogenic fungus Beauveria bassiana (Naturalis L and Botanigard WP) did not provide significant control.
Savona (2%) reduced first instar mealybug numbers by 93%, but had variable effects on mealybugs at other growth stages (2% and 4% dilutions gave 30-60% control and 40-100% control respectively) and would require multiple applications for effective control. Crop oil (a paraffin oil), effectively removed wax from motile and egg stages of mealybugs leading to mortality. Although other products tested (Hyvis 30 Emulsion, Jet 5, undiluted vinegar and Eradicoat T) provided some control on cropping and non-cropping areas (per their approvals) the level of control was inadequate for commercial tomato crops. Hortichem Spraying Oil and Horticide were ineffective. The antifeedant Chess (pymetrozine) provided some control, but was inadequate for a commercial crop. A pheromone used for trapping the citrus mealybug (Plannococcus citri) did not appear effective for P. viburni (Croft, 2007; de Courcy Williams, 2002; Morley and Jacobson, 2008).
Two-spotted spider mite (Tetranychus urticae)
Two-spotted spider mite is well-known as it is has a large number of host plants, including Cordyline and Phormium, and is the most common of the spider mite species found in UK horticulture. Mite feeding damage is caused by the rasping of the lower leaf surface with their mandibles; they then suck the sap from the leaf and leave small pale spots over the surface. Heavy infestations can result in whole leaves turning yellow and the plant dying; large numbers of mites can be found at shoot tips associated with silk webbing. They are easily spread throughout the nursery (Buxton, 2009).
There are a number of biological control options for two-spotted spider mite: Phytoseiulus persimilis, Amblyseius andersoni, A. californicus, A. swirski and Feltiella acarisuga. Of these P. persimilis is the mainstay, although it will only remain when there is prey present and is less effective at high temperature. A. andersoni and A. californicus are useful as they feed on a range of prey, and F. acarisuga feeds on all stages of spider mite. There are several acaricides that are approved for use under protection including Apollo 50 SC (clofentezine), Masai (tebunenpyrad) and Dynamec that are reasonably compatible with IPM programmes. Pyrethroids including Gyro (bifenthrin) and Talstar 80 Flo (bifenthrin) are effective but are not IPM compatible (Buxton, 2009).
Slugs and snails
Slugs and snails are common pests in the UK and affect both Cordyline and Phormium among many plant species, particularly soft, leafy specimens. Symptoms are similar for both pests, as they each graze on leaves and have a rasping, toothed tongue with which they remove plant tissue, generally feeding at night. A distinctive, persistent slime trail is often used to identify the cause of this feeding damage. Slug and snail activity is more severe during warm humid periods, and numbers can be reduced by good nursery hygiene, removing plant litter, moss, liverwort, algae (Buczacki and Harris, 2005).
Several control measures are available including slug pellets, active ingredients metaldehyde, methiocarb and ferric sulphate (Ferramol); Ferramol is claimed to be the more environmentally friendly option. The biological control product Nemaslug, containing the nematode Phasmarhabditis hermaphrodita, is becoming more widely used in the industry and is effective against both slugs and snails. The nematodes are applied when slugs and snails are active in growing media temperatures between 5 0C and 25 0C (Bennison and Schüder, 2006). A number of growers reported in this survey that they use Croptex Fungex against slugs and snails. This product, along with other treatments, has been shown to have a barrier effect, an antifeedant effect, and treated surfaces have been shown to increase the mortality of slugs and snails (Schüder et al., 2004). Croptex Fungex has an approval for use as a fungicide.
Aphids
A number of aphids are found in the UK, with size, colour and host range varying between species. They feed on all plant parts by sucking sap via a stylet which is inserted into plant tissue; excess sap is secreted as honeydew. Aphids cause distortion of new growth, the honey dew encourages colonisation of sooty mould, and they are responsible for viral transmission between plants (Buczacki and Harris, 2005).
There are a number of biological controls available, including the parasitic wasps Aphidius colemani and Aphidius ervi, which only parasitise specific aphid species, and predators such as the midge Aphidoletes aphidimyza, lacewings, hoverflies and ladybirds, which prey on all aphid species. The insect-pathogenic fungus Verticillium lecanii (Vertalec) is also available but not widely used as it requires high humidities in order to be effective. The main aphid species found on Cordyline, particularly C. australis ‘Torbay Dazzler’ (C. australis seems to be unaffected) is Rhopalosiphum padi (the bird cherry aphid), which is parasitized by A. colemani (Buxton, 2009). Chemicals suitable for use in IPM systems are Chess (SOLA 2834/08, pymetrozine), Eradicoat, Majestik, Savona and SB Plant Invigorator. Aphox (pirimicarb) is selective for aphid, but Aphis gossypii and some strains of Myzus persicae are resistant. Nicotine 40% shreds, Calypso (SOLA 3728/06, thiacloprid) and Gazelle (acetamiprid) are moderately harmful to beneficials. The pyrethroids and Spruzit (pyrethrin) are also effective but there has some resistance seen in Aphis gossypii and some strains of Myzus persicae (Pesticides Safety Directorate, 2008).
Thrips
A number of thrips species may be found in glasshouses, including western flower thrips (Frankliniella occidentalisi) and onion thrips (Thrips tabaci). Feeding damage is caused by the piercing of plant cells and sucking sap, which leaves small irregularly shaped white or silvery marks on the leaves and on which small black faecal specks can usually be seen. Thrips can cause further major problems by acting as a virus vector.
A range of controls are available for thrips. Biological controls available are the predatory mites Amblyseius cucumeris, A. Swirskii, Hypoaspis miles, H. aculeifer, Orius laevigata, O. majusculus, the rove beetle Atheta coriaria, lacewings, the nematode Steinernema feltiae, and the insect-pathogenic fungus Verticillium lecanii. Chemical controls safe in IPM systems include Eradicoat, Majestik, and Nemolt (SOLA 2120/07). Other chemicals include Conserve (spinosad), Nicotine 40% shreds, Dynamec (abamectin) and Calypso (SOLA 3728/06, thiacloprid) (Pesticides Safety Directorate, 2008). Several applications are normally required to bring the thrips population under control, and products should be rotated in a programme to reduce the risk of resistance developing.
Diseases
There are numerous reports of fungal and other species linked to Cordyline and Phormium worldwide, including a checklist of fungi found on these species in New Zealand (McKenzie et al., 2005). Common saprophytes and cosmopolitan species that do not impact on plant quality in the context of this report have not been included.
Management of fungal diseases can often be achieved by attention to the growing environment. Fungal pathogens require water in varying quantities to establish and proliferate. Providing unfavourable conditions by, for example, irrigating (overhead) early in the day rather than in the evening to maintain drier leaf surfaces, and by reducing humidity by providing adequate ventilation and spacing between plants helps to control leaf and stem rots. An open growing media and adequate drainage maintains a drier root environment and reduces root and collar rots. Good practice suggests that new stock should be segregated and inspected on arrival and rejected if affected by any unacceptable pests or diseases to prevent the nursery becoming infested. Good nursery hygiene and weed control also help by removing decaying plant debris and alternate hosts which may harbour pathogens and overwintering spores.
There are various chemical control options and consideration of the taxonomic grouping of pathogens can be helpful in selecting the most appropriate. Accurate identification of pathogens is critical to providing the most appropriate treatment and often requires laboratory analysis. In general, for example, oomycetes may be treated with products such as Filex (propamocarb hydrochloride) or Aliette 80 WG (fosetyl-aluminium), Rhizoctonia with Rovral WP (iprodione), Amistar (SOLA 0443/09, azoxystrobin) or Basilex (tolclofos-methyl), rust with Amistar (SOLA 0443/09, azoxystrobin)), Bravo 500 (chlorothalonil) and ascomycetes such as Colletotrichum sp. or Cercospora sp, with Octave (prochloraz) (Pesticides Safety Directorate, 2008).
Samples of Cordyline and Phormium that have been submitted to the FERA plant clinic for investigation provide a historical record of diseases experienced on these plants in the UK. A number of leaf spots occur on Cordyline, including the fungal pathogens Glomerella cingulata, Cercospora sp., Fusarium moniliforme, Phyllosticta dracaenae, Phytophthora parasitica; the bacteria Erwinia spp. and Impatiens necrotic spot virus (INSV) (Lane, 2009). Cordyline are also affected by yellow leaf spot syndrome, the cause of which remains to be established.
Several leaf spots have also been found in Phormium in the UK, the most common of which is Kirramyces phormii, but also Glomerella cingulata. There are reports of fungal pathogens including Phoma sp., Cercospora sp., Stenella sp. and Phyllosticta sp. causing leaf spots; bacterial leaf spots due to Xanthomonas campestris pv phormicola and a Pseudomonas fluorescens/marginalis complex (Lane, 2009).
The following is a brief summary of information relating to the causes of diseases found on Cordyline and Phormium worldwide (not necessarily reported in the UK):
• Botrytis cinerea is a ubiquitous pathogen on many hosts and has been isolated from leaf lesions of Cordyline. In its teleomorphic form (Botryotinia fuckeliana) this pathogen has been associated with damping-off diseases of seedlings in Cordyline and Phormium (McKenzie et al., 2005).
• Candidatus Phytoplasma australiense has been linked to the sudden decline, collapse and death of Cordyline plants in New Zealand (North Island); this phytoplasma has also been linked to Phormium yellow leaf and is spread by sap-sucking insects (Andersen et al., 2001; Liefting et al., 1998).
• Cercospora sp. is seen on Cordyline as pale brown or reddish rectangular leaf blotches which are limited by leaf veins (McKenzie et al., 2005).
• Colletotrichum acutatum has been isolated from leaf spots of Phormium (McKenzie et al., 2005).
• Colletotrichum phormii has been isolated from Phormium plants originating from the UK by USDA microbiologists and in 2006 the US prohibited entry of Phormium tenax infected with this pathogen. It has numerous synonyms and appears to occur only on Phormium spp. (Farr et al., 2006).
• Cylindrocarpon scorparium is often associated with damping-off diseases of Cordyline seedlings (McKenzie et al., 2005).
• Erwinia spp. Symptoms of this bacterial infection include a wet leaf spot, stem rot and root rot with a distinctive smell which tends to occur on infected cuttings. Lesions are usually water soaked and slimy (Henley et al., 2009). There are currently no chemical control options for Erwinia spp.
• Fusarium moniliforme causes reddish-brown round to oval spots, sometimes with a yellow halo and which tend to occur near the growing tip of immature leaves, on either leaf surface (Buczacki and Harris, 2005; Henley et al., 2009).
• Fusarium crookwellense has been found in New Zealand associated with rotting of central leaves at the apex of young Cordyline plants (McKenzie et al., 2005). Fusarium oxysporum has been identified causing plant collapse in Cordyline (Jones, 2008).
• Glomerella cingulata (Ascomycete) is pathogenic on many hosts including, Cordyline and Phormium. Colletotrichum gloeosporioides is the asexual stage. The leaf spots caused by Glomerella cingulata are an elongated diamond shape, and are found on both upper and lower leaf surfaces; on the upper surface they are pale brown with a dark brown margin and they are lighter coloured on the lower surface with many perithecia and a dark margin.
• Impatiens necrotic spot virus (INSV) causes leaf spots, ring spots and stunting in a range of plants and has been recorded on Cordyline (Roggero et al., 1999). Thrips, including Frankliniella occidentalis (Western flower thrips) and Thrips tabaci (onion thrips) are the virus vector, therefore these need to be monitored (blue sticky traps) and controlled to prevent spread of the virus as there is no treatment for the virus itself (Buczacki and Harris, 2005).
• Kirramyces phormii. Phormium is the host of Kirramyces phormii, now Phaeophleospora phormii (Crous et al., 1997). It causes an oval, reddish or purple leaf spot on the upper leaf surface of Phormium and dark brown to black on the lower surface (McKenzie et al., 2005).
• Periconiella cordylines causes an indistinct, reddish brown leaf speckle on Cordyline. P. phormii (syn. Stenella dianellae), causes a large, distinctive reddish purple blotch on the lower leaf surface, and is endemic and widespread throughout New Zealand (McKenzie et al., 2005).
• Phoma spp. Various undetermined Phoma have been isolated from leaf spots in New Zealand (McKenzie et al., 2005). Phoma nebulosa is recorded on Cordyline (Kinsey, 2002).
• Phyllosticta dracaenae causes circular or irregularly shaped leaf spots, brown with purple borders and yellow halos which vary in size between 1-5 mm in diameter and occur mainly on older leaves (Henley et al., 2009). P. cordylinophila has been found on Cordyline in Portugal, Hawaii and Japan and causes reddish brown circular or irregular leaf spots, (McKenzie et al., 2005).
• Phytophthora parasitica produces lesions, initially water soaked and brown with irregular margins and tends to occur on the lower leaf surface. (Henley et al., 2009). Phytophthora spp. can also be the cause of root, crown and basal stem rot. Symptoms are poor growth, wilting and plant collapse. Roots become water-soaked, brown or black and soft; the stem base becomes discoloured reddish-brown (O'Neill and Ann, 2004).
• Pythium spp. Root and basal stem rot produces similar symptoms to Phytopthora on the aerial part. Affected roots become grey or brown, shrivelled and water soaked; symptoms are sometimes confined to thin lateral roots or root tips. Pythium also causes damping-off in seedlings and cuttings (O'Neill and Ann, 2004).
• Pseudomonas spp. (bacteria) have been isolated from Cordyline, but there is little descriptive information (Madhusmita et al., 1999).
• Rhizoctonia solani causes damping-off of seedlings and cuttings, root and crown rots, and occasionally leaf and stem blight. The stem base can be discoloured and restricted at the growing media surface (wire-stem), and on mature plants may appear as brown sunken lesions on the stem at or just above the growing media surface. Dry lesions which progress inwards may occur on cutting stems and fungal hyphae may be visible (O'Neill and Ann, 2004).
• Sphaeropsis cordylines is currently only known from New Zealand, but causes large dark brown oval leaf spots with dimensions up to 20 x 10 mm on Cordyline (McKenzie et al., 2005).
• Uredo phormii is a rust fungus, widespread in New Zealand but not common, and found only on Phormium (McKenzie et al., 2005).
• Yellow leaf spot syndrome (Figure 1) is found in Cordyline. Symptoms are small raised pustules, initially chlorotic, sometimes appearing water-soaked and sometimes becoming necrotic. Although this is sometimes thought to be due to rust, no rust pathogens have been recorded on Cordyline. Microscopic examination has revealed swollen plant cells that could suggest a hypersensitive response to infection, pest feeding damage or physiological disorder such as oedema (Lane, 2009).
|a |[pic] |b |[pic] |c |[pic] |
Figure 1 Cordyline plants showing symptoms of yellow leaf spot syndrome, (a) and (b)(Bartlett, 1981; England, 2007; Lane, 2009) (c)(England, 2007)
Disorders
Oedema
Oedema typically occurs under conditions of warm, moist soil and high humidity, when roots absorb water faster than they can use it or it can be lost through transpiration. This causes plant cells to swell as water continues to be taken up, resulting in blistering and chlorotic spots which may occur on the leaves, stems, flowers or fruit of susceptible plants (San Marcos Growers, 2005).
Oedema is common on Agave attenuata and A. desmettiana ‘Joe Hoak’ (San Marcos Growers, 2005), close relatives of Cordyline and Phormium, and is well documented in numerous other species including Eucalyptus (Pinkard et al., 2006) Solanum tuberosum (potato) (Seabrook and Douglass, 1998), ivy leaf geranium (Rangarajan and Tibbitts, 1994), Solanum melongena (aubergine) (Eisa and Dobrenz, 1971) and Begonia elatior (Papenhagen, 1986).
Development of oedema was increased by high relative humidity and light quality (no UV-B) (Lang and Tibbitts, 1983; Papenhagen, 1986), and increased with declining light intensity in tomato (Sagi and Rylski, 1978). Oedema was reduced when light quality was adjusted using yellow filters in potatoes (Lang and Tibbitts, 1983; Seabrook and Douglass, 1998) and with addition of far-red to red irradiance, or by providing far-red irradiance immediately after red irradiance (Morrow and Tibbitts, 1988). Oedema has been successfully induced in leaf discs of various species (Eucalyptus globus, Ipomoea batatas, Lycopersicon esculentum, Pelargonium peltatum, Populus tremula, Solanum tuberosum) by controlling humidity, UV radiation and temperature in growth chamber experiments.
Poor leaf colour
A dark, dull appearance to Cordyline is attributed to light intensity (high or low), low fertiliser levels or high temperatures, and there are recommendations that shade should be applied in high summer light levels and supplementary light applied in winter, and that moderate fertiliser levels and temperatures should be maintained (Moorman, 2009).
Tip death
Very young leaves have been reported with leaf tip damage attributed to fertiliser or leaf shining chemicals. It was suggested that fertilisers should not be applied over the growing point or young leaves (Moorman, 2009).
Nutritional influences
Nutrient deficiency and toxicity can be a cause of leaf margin and tip browning, including calcium, potassium and boron deficiency, and fluoride and boron toxicity. Whilst there are numerous reports of these nutritional disorders in both dicotyledonous and monocotyledonous plants, only fluoride toxicity has been specifically reported in Cordyline and none in Phormium.
Fluoride toxicity
Much of the recent interest in the phytotoxic effects of fluorides has developed as a result of high levels of plant injury found near large cities and where industries such as aluminium smelting and phosphate extraction are based; fluoride is released when clays, rocks or other material containing it are heated, or it is used as a flux and then released into the air (Treshow, 1971). Plants express a large range of sensitivity to fluoride with the most sensitive, such as Lolium perenne, Gladiolus spp. and Hypericum perforatum, cited as indicators of fluoride pollution (Fornasiero, 2001). Phormium tenax and Cordyline australis are listed as sensitive to fluoride (Doley et al., 2004; Weinstein and Davison, 2003).
Fluorides are absorbed by plants from the atmosphere via foliage, through the stomata, and from substrates (originating from the substrate or water) via the roots, with each route producing different patterns of necrosis within leaves; damage is mainly confined to leaf tips and margins in the former, whilst with substrate-derived fluoride necrotic areas appear more random within the leaf and are lacking in the margins (Woltz, 1964). Fornasiero (Fornasiero, 2001) observed that in Hypericum perforatum sodium fluoride (NaF) from the substrate entered the plant through the root and travelled in the xylem via the transpiration stream to leaf tips and margins, where greatest evaporation occurs. There does not appear to be movement of fluoride downwards from leaves to roots (Brennan et al., 1950).
Typical macroscopic symptoms of fluoride toxicity are tip and margin necrosis, commonly termed ‘tip burn’, with a distinct reddish-brown line separating it from healthy tissue; it occurs in both monocotyledons and broad leaved plants. The most severe symptoms are reported in fully expanded, middle aged leaves, with only tip necrosis found in older and young leaves (Fornasiero, 2001), although this varies between plant species; in Pinus spp. younger leaves are more susceptible (Davison et al., 1974). Symptoms progress through chlorosis and desiccation of tissue which becomes brown and necrotic.
Microscopic changes in the ultrastructure of Hypericum perforatum due to fluoride toxicity are distortion of the leaf epidermal layers, mesophyll cell collapse, and detachment of the plasma membranes from cell walls; alteration of chloroplasts and an increase in plastoglobule (lipoprotein particles within chloroplast) number and size. Presence of the antioxidant superoxide dismutase content decreases, reducing the plant’s ability to counteract reactive oxygen species. Chlorophyls a and b, and carotenoid content are significantly reduced (Fornasiero, 2001).
Leaf necrosis due to fluoride toxicity has been recorded in a number of monocotyledons such as Gladiolus (Woltz, 1964), Freesia (Wolting, 1975) and Cordyline (Conover and Poole, 1971; Fornasiero, 2001), and dicotyledons such as Chrysanthemum and Antirrhinum (Marousky and Woltz, 1975).
Conover and Poole (1971) found Cordyline terminalis ‘Baby Doll’ sensitive to fluoride, developing foliar necrosis during propagation in fluoride levels above 0.25 mg L-1 in soil or water; severity increased with lower substrate pH and with reduced light levels (shaded glasshouse conditions compared with lighted air conditioned laboratory conditions). Necrosis also occurred in misted cuttings in vermiculite, perlite and Terragreen, but not at significant levels in various barks and peats tested (Poole and Conover, 1975).
The addition of superphosphate (3.80 kg m-3, 1.5% fluoride) has been found to increase necrosis and tissue fluoride content of cuttings of Cordyline terminalis ‘Baby Doll’ grown in German peat and Turface. The effect was reduced by supplementation with calcium sulphate and magnesium sulphate treatments, and in each case as the dose was increased (1.9 kg m-3 to 3.8 kg m-3) less necrosis was recorded (Poole and Conover, 1975). Materials used in potting mixes with fluoride rates over 100 mg L-1 dry weight, which are considered high, include superphosphate (2600 mg L-1), diammonium phosphate (2000 mg L-1) and triple superhosphate (1600 mg L-1) (Bunt, 1988). In soils, fluoride and calcium can combine to form insoluble calcium fluoride, rendering the fluoride unavailable to plants. There has been concern that the level of fluoride in perlite may cause phytotoxicity, however this was dismissed by Bunt (1988) as perlite has minimal cation exchange capacity and low fluoride content (17 mg L-1) depending on perlite source.
Fluoride toxicity in all crops may be avoided by raising the pH of the growing media to 6.0 to 6.5, using phosphoric acid instead of superphosphate and avoiding irrigating with water with greater than 0.25 mg L-1 fluoride (Bunt, 1988). The recommended maximum fluoride level for irrigation water is 1.0 mg L-1 (Holmes and Adlam, 2006). In the UK a number of water authorities add fluoride to mains water to reduce teeth decay in children. Where fluoridation does take place the concentration must be maintained at 1.0 mg L-1 with a maximum concentration of 1.5 mg L-1 permitted under the Water Supply (Water Quality) Regulations 2000 in England. The majority of the UK has levels below 0.49 mg L-1; whilst there appears to be areas where levels reach 1.0 mg L-1 (Cheshire, Nottinghamshire, Leicestershire, West Midlands, Worcestershire, Suffolk, Cambridgeshire, Bedfordshire, Essex, Northamptonshire and Berkshire); and 1.5 mg L-1 (Berkshire, Essex, Nottinghamshire, Leicestershire and Northamptonshire) (Defra, 2008). The British Geographical Survey provides data derived from 30,000 analyses indicating fluoride levels in the majority of UK streams range from below 0.05 mg L-1 in areas of Wales, Cumbria and Scotland to above 0.35 mg L-1 in eastern and south eastern England, but does not provide a precise maximum level (British Geological Survey, 2005). In the UK almost all mains water supplies have a pH greater than 7 as suppliers add alkali to adjust the pH of water before it leaves the water treatment works (The British Fluoridation Society, 2009). This suggests that UK water supplies could have fluoride levels greater than the 0.25 mg L-1 recommended by Bunt (1988), particularly where mains water is fluoridated to 1.0 mg L-1 or borehole / reservoir water has a high natural level of fluoride, and this could cause tip burn on fluoride-sensitive Cordyline and Phormium crops.
Calcium deficiency
Calcium deficiency has not been reported in Cordyline or Phormium. In general, calcium deficiency symptoms in vegetative growth are seen as stunting of plants and pale leaf margins followed by necrosis, mainly in young leaves; leaves may also curl inwards, and plant tip death occurs in acute cases. Roots are also affected, with young roots and root hairs dying and older roots turn brown (Bunt, 1988). Calcium deficiency has been observed in a range of plant species including Cornus alba, Hibiscus syriacus, Hydrangea paniculata ‘Grandiflora’ (Aenderkerk, 1997), lettuce, cucumber, tomatoes, carrots, cauliflower, strawberries (Bould et al., 1983).
Boron deficiency and toxicity
No literature was found relating boron toxicity or deficiency to either Cordyline or Phormium. Boron deficiency symptoms vary between plant species, but can include leaf chlorosis of young leaves and stems, tip burn and weak growth in rice (Bunt, 1988; Yu and Bell, 1998).
Boron toxicity causes narrow brown or black leaf edge necrosis in older leaves (Bould et al., 1983); boron is carried in the transpiration stream and deposited at leaf margins and causing areas of high boron concentration, as seen in sensitive plants e.g. Chrysanthemum, Poinsettia and Zinnia. Bunt ( 1988) recommends boron application as frits, as the slow release action reduces the risk of toxicity.
Potassium deficiency
No literature was found relating to potassium deficiency in Cordyline or Phormium. Potassium is involved in numerous cell functions including transport of sugars around the plant. Deficiency may be expressed initially by browning of the leaf margin followed by necrosis of the leaf edge and progresses to interveinal areas (Bragg, 1998). Potassium is very mobile, causing deficiency symptoms in older leaves as the nutrients are preferentially mobilised from old to new leaves (Taiz and Zeiger, 2006).
Initial survey results
The respondents
44 growers participated in the initial survey, spread throughout the UK (Table 1). Of the growers who responded, 34 grew Cordyline and 36 grew Phormium. A number of growers were not able to answer all of the questions. The geographical spread of growers selected for the case studies is shown in Table 2. Growers have on occasion mentioned chemicals which have been revoked and this has been noted within the text.
Table 1. Geographical spread of growers who participated in the initial survey
|Southeast |Southwest |Northeast |Northwest |
|Kent |Cornwall |North Yorkshire |West Yorkshire |
|Surrey |Devon |Lincolnshire |Lancashire |
|West Sussex |Dorset |East Yorkshire |Cheshire |
| |Somerset | | |
|East |West |South |Scotland |
|Rutland |Herefordshire |Hampshire |Glasgow |
|Suffolk |Worcestershire |Isle of Wight | |
|Norfolk |Staffordshire | |
|Cambridgeshire |West Midlands | |
|Hertfordshire |Gwynedd | | |
Table 2. Geographical spread of growers who participated in the case studies
|West |East |South |
|Gwynedd |Suffolk |Hampshire |
|Herefordshire | | |
|Southeast |Northeast |Southwest |
|West Sussex |East Yorkshire |Dorset |
Cordyline
Growers were asked to provide details of the major Cordyline varieties they grow (Table 3) and their provenance (Table 4). Where growers had sourced the same variety from more than one producer the variety was only counted once. Where a grower had sourced more than one product line from a supplier, each was included individually. A total of thirty three growers responded.
Where UK was stated as the country of origin plants may have been produced by tissue culture abroad then grown on in plugs in the UK until distribution as UK-produced product. Two nurseries who replied were unable to provide this information. Figures represent the number of times a variety of Cordyline was sourced from the country of origin (Table 4).
Table 3. Cordyline varieties grown by the respondents
|Variety |No. of growers |Variety |No. of growers |
|australis |27 |‘Firecracker' |2 |
|australis 'Red Star' |23 |australis 'Atropurpurea' |1 |
|australis 'Torbay Dazzler' |20 |‘Purple Tower' |1 |
|‘australis 'Sundance' |9 |australis 'Peko' |1 |
|‘Southern Splendour' |6 |australis 'Pink Stripe' |1 |
|australis 'Torbay Red' |5 |australis 'Red Sensation' |1 |
|australis Purpurea Group |4 |‘Eurostar' |1 |
|‘Sunrise' |4 |‘Eurostripe’ |1 |
|australis 'Purple Sensation' |3 |‘Dark Star' |1 |
|australis 'Pink Passion' |3 |‘Red Comet' |1 |
|australis 'Pink Champagne' |2 |'Cherry Sensation' |1 |
|australis 'Sparkler' |2 |‘Red Festival Grass' |1 |
Table 4. Country of origin of Cordyline grown in the UK
|Country of origin |No. growers |Country of origin |No. growers |
|UK |33 |Italy |3 |
|Holland |12 |Ireland |2 |
|China |8 |Australia |1 |
|Spain |5 |New Zealand |1 |
|India |4 | | |
Growers provided details of the companies from which they sourced their Cordyline stock. A total of 35 different suppliers were listed by growers, who supplied five different categories of product (Table 5). Four nurseries did not provide specific supplier information, either leaving the space blank or recording ‘various’.
Table 5. Categories of Cordyline suppliers
|Supplier category |No. suppliers |
|Seed suppliers |5 |
|Micro-propagators / plug producers |13 |
|Liner producers |9 |
|Suppliers of plants larger than liners |9 |
Growers reported that a total of 924,663 Cordyline were grown and 866,502 sold by them each year. One grower did not respond to this question. Growers were asked to state how many Cordyline they produce and purchase at different production stages (Table 6). Data was provided by 26 growers.
Table 6. Total number of Cordyline either produced or purchased by growers at each production stage.
| |No. of plants |
| |Purchase |Produce |
|Plug |203,300 |536,000 |
|Liner |300,200 |110,850 |
|1-3 L |265,510 |77,564 |
|4-5 L |37,000 |250 |
|> 5L |7,315 |2,429 |
Growers were asked to indicate the pests and diseases observed on their Cordyline crop and the success of any control measures used. Level of success was graded into ‘Good’, ‘Moderate’ and ‘Poor’, and some measures fell into multiple categories as growers had mixed success (Table 7). Eleven Cordyline growers reported no pest problems. The majority could not give a precise cost of crop value affected, but the total figures provided have been stated. Pests had affected all crop stages. Not all growers gave an indication of success. Croptex Fungex and Cuprokylt have approvals for use as fungicides, however growers noted in the survey that they were used against slugs and snails.
Growers also provided details of the diseases or disorders observed on their Cordyline crop and the success of any control measures used (Table 8). Eight growers recorded no disease problems on Cordyline. The majority could not give a precise cost of crop value affected, but the figures provided have been stated. Diseases had affected all crop stages from mature plugs to finished product. Growers have registered problems with yellow leaf spots and oedema, but they may refer to the same symptoms in some instances. Botrytis affected newly potted plugs and oedema affected finished and overwintered stock. All other diseases affected all production stages from mature plugs to finished product. Comments regarding the success of treatments have been recorded against each, and in some cases could not be given as the results were yet to be seen. A number of growers did not apply treatments, but discarded crops.
Table 7. Pests found on Cordyline and the control measures used by respondents.
|Pest |No. growers affected |Value of crop affected (£)|Control measures |Were these measures |
| | | | |successful? |
|Mealybug |4 |>109,000 |Decis & Calypso |Good |
| | | |Dursban WG | |
| | | |Calypso | |
| | | |Gazelle | |
|Thrips |3 |>11,000 |Amblyseius cucumeris |Good |
| | | |Conserve | |
| | | |Calypso | |
| | | |Nicotine 40% shreds | |
| | | |Dynamec | |
|Slugs |9 |Not provided |Slug pellets |Good |
| | | |Nemaslug | |
| | | |Croptex Fungex | |
| | | |Cuprokylt | |
| | | |Ferramol | |
|Snails |10 |>12,000 |Slug pellets |Good |
| | | |Nemaslug | |
| | | |Croptex Fungex | |
| | | |Cuprokylt | |
| | | |Ferramol | |
| | | |Metaldehyde | |
|Aphid |5 |>1,092,888 |Chess |Good |
| | | |Aphox | |
| | | |Calypso | |
| | | |Toppel 100 EC | |
| | | |Spruzit | |
| | | |Aphidius colemani | |
| | | |Aphidoletes | |
| | | |Agri-50 | |
|2-spotted spider |19 |Not provided |Apollo 50 SC |Good |
|mite* | | |Dynamec | |
| | | |Floramite 240 SC | |
| | | |SB Plant Invigorator | |
| | | |Gyro | |
| | | |Talstar | |
| | | |Majestik | |
| | | |Masai | |
| | | |Oberon* | |
| | | |Spraying oil | |
| | | |Phytoseiulus persimilis | |
| | | |Amblyseius californicus | |
|Vine weevil |1 |2,000 |Cyren |Moderate |
| | | |Nematodes | |
*NB. Oberon may cause growing point damage in Cordyline.
Table 8. Diseases and disorders found on Cordyline and the control measures used.
|Disease / disorder |No. growers |Affected crop |Control measures |Were these measures |
| |affected |value (£) | |successful? |
|Leaf spots (yellow) |19 |119,437 |Amistar |Good |
| | | |Remove affected leaves | |
| | | |Pot on | |
| | | |Octave |Moderate |
| | | |Liquid feed | |
| | | |Fungal programme | |
| | | |Amistar |Poor |
| | | |Octave | |
| | | |Systhane 20 EW | |
| | | |Croptex Fungex | |
| | | |Bumper 250 EC | |
|Leaf spots (other) |8 |12,250 |Octave |Good |
| | | |Avoid water splash | |
| | | |Octave |Poor |
| | | |Feeding | |
| | | |Octave |Unsure |
| | | |Amistar | |
|Tip burn |10 |1,055,600 |Water management |Good |
| | | |Calcium in feed / foliar sprays. | |
| | | |Site selection (fluoride level) | |
| | | |Temperature control | |
| | | |Liquid feed |Moderate |
| | | |Frost protection | |
| | | |Control humidity |Poor |
| | | |Octave |Unsure |
| | | |Amistar | |
|Stem / crown rot |11 |19,425 |Curve |Good |
| | | |Rovral WG | |
| | | |Subdue | |
| | | |Aliette 80 WG | |
| | | |Aliette 80 WG |Moderate |
| | | |Subdue |Poor |
| | | |Proplant | |
| | | |Aliette 80 WG | |
| | | |Dry plants out | |
| | | |Space | |
| | | |Delsene 50 Flo (not approved for use on | |
| | | |ornamentals) | |
| | | |Amistar | |
| | | |Avoid wet foliage |Unsure |
| | | |Rovral WG | |
| | | |Amistar | |
|Root rot |9 |28,564 |Discard plants, stop production |Good |
| | | |Aliette 80 WG |Moderate |
| | | |Subdue | |
| | | |Dry out growing media | |
| | | |Careful, low level watering |Unsure |
|Oedema |3 |50,000 |Maintain temperature > 6 0C |Moderate |
| | | |Grow under glass | |
|Botrytis |1 |5,000 |Fungicide (sprayed too late) |Poor |
Phormium
Growers provided details of the major Phormium varieties they grow (Table 9) and their provenance (Table 10). Where growers had sourced the same variety from more than one producer the variety was only counted once. Where a grower had sourced more than one product line from a supplier, each was included individually. A total of thirty six growers responded.
Table 9. Phormium varieties grown by the respondents.
|Variety |No. growers |Variety |No. of growers |
|‘Yellow Wave' |23 |‘Rainbow Maiden' |4 |
|tenax |19 |‘Duet' |3 |
|tenax purpureum group |18 |‘Margaret Jones' |3 |
|‘Bronze Baby' |15 |‘Amazing Red' |2 |
|‘Sundowner' |15 |‘Dark Avocado' |2 |
|‘Jester' |15 |‘Rainbow Chief' |22 |
|cookianum subsp. hookeri 'Cream Delight' |13 |‘Red Sensation' |2 |
|cookianum subsp. hookeri 'Tricolor' |12 |‘Black in Black |1 |
|‘Apricot Queen' |11 |‘Black Velvet |1 |
|‘Evening Glow' |9 |‘Crimson Devil |1 |
|‘Pink Panther' |8 |‘Dazzler' |1 |
|‘Alison Blackman' |7 |‘Glowing Embers' |1 |
|‘Pink Stripe' |7 |‘Golden Alison' |1 |
|cookianum ‘Flamingo' |6 |‘Maori Maiden' |1 |
|‘Gold Ray' |6 |‘Maori Sunrise' |1 |
|‘Rainbow Queen' |7 |‘Rainbow Surprise' |1 |
|‘Platt's Black' |5 |‘Surfer' |1 |
|‘Rainbow Sunrise' |6 |tenax 'All Black' |1 |
|tenax 'Variegatum' |5 |tenax 'Veitchianum' |1 |
|‘Black Adder' |4 |‘Sunset' |1 |
|‘Gold Sword' |4 |‘Merlot' |1 |
|‘Maori Queen' |4 |‘Peach Melba' |1 |
Where the UK was stated as the country of origin plants may have been produced by tissue culture abroad, grown on in plugs in the UK and then further distributed as UK-produced product.
Table 10. Country of origin of Phormium grown by the respondents.
|Country of origin |No. growers |Country of origin |No. growers |
|UK |28 |South Africa |2 |
|France |7 |Africa |1 |
|Ireland |4 |Holland |1 |
|New Zealand |3 |Italy |1 |
Growers provided details of the companies they sourced their Phormium stock from (Table 11). Four nurseries did not provide specific supplier information, either leaving the space blank or recording ‘various’. A total of 32 different suppliers were listed by growers, who supplied five different categories of product. 53 growers propagated their own Phormium.
Table 11. Categories of Phormium suppliers.
|Supplier category |No. suppliers |
|Seed suppliers |2 |
|Micro-propagators / plug producers |10 |
|Liner producers |14 |
|Suppliers of plants larger than liners |8 |
Growers reported that a total of 1,238,961 Phormium were grown and 1,113,517 sold by them on each year. Growers were asked to provide the average number of Phormium grown and sold by them on their nursery each year. One grower did not provide this information.
Growers indicated how many Phormium they produce at each production stage (Table 12). Data was provided by 28 growers.
Table 12. Total number of Phormium either produced or purchased by growers at each production stage annually.
| |No. plants |
| |Purchase |Produce |
|Plug |57,300 |530,000 |
|Liner |153,875 |562,800 |
|1-3 L |42,340 |246,380 |
|4-5 L |2,200 |20,700 |
|> 5L |2,450 |44,100 |
Growers were asked to indicate the pests and diseases observed on their Phormium crop and the success of any control measures used. Level of success was graded into ‘Good’, ‘Moderate’ and ‘Poor’, and some measures fell into multiple categories as growers had mixed success. Three Phormium growers did not experience any pest problems on their crops. Mealybugs affected crops from the liner stage to the finished plant; there was no data for aphids. Other pests recorded affected all stages. The combination of Talstar 80 Flo + Majestik in December, Masai + Apollo 50 EC in late March and Floramite 240 EC + Oberon in summer was found to be successful by one grower. Croptex Fungex and Cuprokylt have approvals for use as fungicides, however growers reported in the survey that they were being used against slugs and snails.
Table 13. Pests found on Phormium and the control measures used by respondents.
|Pest |No. growers |Value of crop |Control measures |Were these measures |
| | |affected (£) | |successful? |
|Mealybug |19 |253,820 |Temik 10G (no longer approved) |Good |
| | | |Gazelle | |
| | | |Chess | |
| | | |Intercept 70 WG | |
| | | |Imidasect 5 GR | |
| | | |Dursban WG | |
| | | |Spraying oil | |
| | | |Gazelle |Moderate |
| | | |Chess | |
| | | |Intercept 70 WG | |
| | | |SB Plant Invigorator | |
| | | |Gyro | |
| | | |Decis | |
| | | |Calypso | |
| | | |Exemptor | |
| | | |Cryptolaemus montrouzieri |Poor |
| | | |Decis protech | |
| | | |Dimethoate 40 | |
|Thrips |4 |No data |Nicotine 40% shreds |Good |
| | | |Conserve | |
| | | |Dynamec | |
| | | |Amblyseius cucumeris | |
| | | |Parapet |Poor |
|Slugs |15 |74,805 |Ferramol |Good |
| | | |Croptex Fungex | |
| | | |Nemaslug | |
| | | |Metaldehyde | |
|Snails |16 |85,403 |Ferramol |Good |
| | | |Croptex Fungex | |
| | | |Nemaslug | |
| | | |Slug bait | |
|Aphid |1 |No data |Calypso |Good |
| | | |Agri-50 | |
| | | |Aphox | |
|Two-spotted spider |20 |306,785 |Apollo 50 SC |Good |
|mite | | |Gyro | |
| | | |Torq | |
| | | |Amblyseius californicus | |
| | | |Phytoseiulus persimilis | |
| | | |Dynamec | |
| | | |Floramite 240 SC | |
| | | |Oberon | |
| | | |Majestik | |
| | | |Masai | |
Growers were asked to report the diseases or disorders observed on their Phormium crop and the success of any control measures used (Table 14). Thirteen Phormium growers did not experience disease problems with their crop. Responses indicated that all diseases listed had affected all crop stages. A spray programme including Amistar 80 WG, Systhane 20 EW, Signum and Octave was found to be successful against general leaf spots. Leaf spots can extend from the base of the leaf into the crown. Two growers commented that tip burn affects Phormium ‘Alison Blackman’ and that frost protection can help for this specific variety. Many growers did not apply treatments.
Table 14. Diseases and disorders found on Phormium and the control measures used.
|Disease / disorder |No. growers |Value of crop |Control measures used (chemical |Were these measures |
| | |affected (£) |or other) |successful? |
|Leaf spots (yellow) |5 |3,375 |Systhane 20EW |Good |
| | | |Amistar 80 WG | |
| | | |Octave | |
|Leaf spots – other |6 |60,000 |Octave |Good |
| | | |Bravo 500 | |
| | | |Bavistin (no longer approved) | |
| | | |Amistar | |
| | | |Systhane 20EW | |
| | | |Signum | |
| | | |Space plants | |
| | | |Octave |Poor |
|Tip burn |6 |19,750 |No successful treatment | |
|Stem / crown rot |9 |85,300 |Rovral WG |Good |
| | | |Subdue | |
| | | |Aliette 80 WG | |
| | | |Octave | |
| | | |Don’t overwater | |
| | | |Discard | |
| | | |Pot less deep |Moderate |
|Root rot |11 |137234 |Subdue |Good |
| | | |Aliette 80 WG | |
| | | |Bio Fungus WP |Moderate |
| | | |Cultural |Unsure |
| | | |Changed potting mix | |
| | | |Potted les firmly | |
Cultural considerations
Growers provided details relating to the quality of the irrigation water used on their nursery with reference to their Cordyline and Phormium crops (Table 15). Twenty growers had their irrigation water analysed regularly. Only eight knew the level of fluoride found in their irrigation water, as this is not generally included in standard water analyses. Further information was gathered that indicated that three of the water authorities servicing the respondents fluoridate the water they provide to some areas, but none of the respondents were located within these areas (Table 16).
Table 15. Details of irrigation water analysis frequency.
|How often do you have your water analysed? |No. of growers |
|Not grown |7 |
|No response |5 |
|Never |14 |
|Occasionally |2 |
|Every 2-3 yr |2 |
|Annually |6 |
|Every 6 months |7 |
|Every 3 months |1 |
Table 16. Details of fluoridation measures taken by the water authorities servicing respondents.
|Which authority supplies your water? |No. growers |Is fluoride added to your irrigation water by your supply|
| | |authority? |
|Borehole |6 |N/A |
|Anglian Water |4 |Anglian Water add fluoride in some areas, but the |
| | |nurseries that responded were not located in a |
| | |fluoridation zone. There is a postcode search on their |
| | |website which provides this information. |
|Southern Water |5 |No fluoride is added to water supplies |
|Severn Trent Water |3 |Water is added to 45% of the area covered by Severn Trent|
| | |Water, but the nurseries that responded were not located |
| | |in fluoridation zones. |
|Wessex Water |3 |No fluoride is added to water supplies |
|South West Water |2 |No fluoride is added to water supplies |
|Thames Water |2 |No fluoride is added to water supplies |
|United Utilities |2 |United Utilities add fluoride in 3 areas, but the |
| | |nurseries that responded were not located in fluoridation|
| | |zones. There is a postcode search on their website |
| | |which provides this information. |
|Yorkshire Water |2 |No fluoride is added to water supplies |
|Portsmouth Water |2 |No fluoride is added to water supplies |
|Reservoir water |1 |N/A |
|Three Valleys Water |1 |No fluoride is added to water supplies |
|Welsh Water |2 |No fluoride is added to water supplies |
Growers gave details of the irrigation system used for their Cordyline and Phormium crops, and the majority used overhead irrigation (Table 17).
Table 17. Irrigation systems used by respondents (%**).
| | | |Growers (%**) | | |
| |Overhead |Drip |Capillary matting |Efford sand bed* |Low level (seep) |
|Cordyline |100 |12 |9 |12 |3 |
|Phormium |94 |11 |6 |11 |0 |
*Drained bed sub-irrigated via header tank or similar (e.g. sand-bed irrigated by lay-flat tube). **Percentages are based on 34 Cordyline growers and 36 Phormium growers.
Growers provided details of the nutrient products applied to their Cordyline and Phormium crops. As nursery stock growers, the majority used controlled release fertilisers (CRFs) (Table 18).
Table 18. Nutrient products used by respondents (%*).
| |Growers (%*) |
|Base fertilisers |47 |
|Controlled Release Fertilisers |83 |
|Liquid feed |39 |
|Supplementary feed |22 |
|Compost tea |6 |
*Percentages are based on 36 growers.
The majority of growers provided protection to their Cordyline and Phormium (Table 19).
Table 19. Protection provided to Cordyline and Phormium crops.
| |Growers (%*) |
| |Cordyline |Phormium |
|Glass |68 |50 |
|Polytunnel (unvented) |44 |39 |
|Polytunnel (vented) |44 |44 |
|Growth room |3 |3 |
|None |6 |8 |
*Percentages are based on 34 Cordyline growers and 36 Phormium growers.
Growers were asked if they had any preferences or comments to make related to any future Cordyline or Phormium crop research. The comments made are quoted below. Twenty six growers were interested in participating further in this project.
|“The main problem is the virus-like leaf markings“. |
|“Good study“. |
|“Watering levels, particularly in Cordyline are critical, especially during the winter. Planting / potting depth of Phormium |
|is also important. These should be considered in future research“. |
|“The disease I think we get is Glomerella. It is not much of a problem in summer, but can be bad overwinter when the foliage |
|is damp, despite sub-irrigation. Spider mite is a problem and Phytoseiulus does not spread out well in spiky crops“. |
|“We have experienced poor rooting establishment under glass. 3 L plants grown outside one year resulted in well rooted |
|plants. This was attributed to wind blow inducing formation of 'prop' roots. Work is needed on Phormium mealybug |
|biocontrol“. |
|“Would like to know why P. 'Alison Blackman' is so badly affected by tip burn in the late autumn (I'm sure it's nutritional). |
|Is a disease responsible for the brown/black circular spots in Cordyline? Any particular nutritional 'design' needed for a |
|good product. Growing media specification bespoke for Cordyline and Phormium attached“. |
|“Phormium are a major crop with us with a value up to £50,000!! “ |
|“Don't do this research - spend money on Phytophthora ramorum“. |
|“Problems with Cordyline crown rot are the main issue where there is a need for research. Leaf spots can be controlled with a|
|successful spray program. With crown rot cultural issues such as watering, compost, ventilation and general husbandry are all |
|the main issues, along with the source of material“. |
|“We would be interested in: compost recommendations, potting timings for spring sales of saleable crops, minimum winter |
|temperatures“. |
|“Largest problem on cordylines are tip burn, basal stem rots and spots on australis. Problem with Phormium is mealybug. |
|Looking at using compost tea in the hope they will prevent stem rots and unstable plants“. |
|“I expect most problems are due to cultural aspects of production e.g. Cordylines only have foliar/root problems in older |
|crops, which should have been potted or shipped out earlier. We have had problems with small water snails on Cordyline ‘Red |
|Star’. Cordyline ‘Sundance’ had been dropped from our range for several reasons. ‘Phormium’ do tend to get root death over |
|winter, whether the crop is run wet or dry. Single colour varieties perform better than variegated, with fewer problems“. |
|“Phormiums are not really a problem other than red spider. Cordyline leaf spot or blotch is a real problem, particularly on |
|green australis“. |
|“The problem with Cordylines has become more of a problem each year, to the point where this year's crop has been destroyed“. |
|“Main problem - virus-like leaf markings“. |
Case study results
Data for the case studies was collected from eight nurseries, all of which grew both Cordyline and Phormium.
Humidity
Growers provided protection to their crops to allow more control of irrigation in wet weather, thereby reducing humidity around plants as well as within the growing media. Details of the space provided to plants was stated (Table 20), and this depended on various factors including:
• Some growers only spaced plants when larger than 5 L or not sold; one grower used a spacing of 10 cm for 12 L pots of both Cordyline and Phormium
• Sale cycle. Phormium on a short sale cycle were kept pot thick and those on a long sale cycle were kept with 5 cm spacing.
• Habit: Phormium with an upright habit were given little spacing but those with an arching habit were given more space.
Table 20. Plant spacings used by growers (cm).
| | |Plug |Liner |1-3 L |> 5 L |
|Cordyline |Initial spacing |Trays |Trays |0-25 |40-100 |
| |Final spacing |Trays |Trays |0-25 |40-100 |
|Phormium |Initial spacing |Trays |Trays |0-25 |40-100 |
| |Final spacing |Trays |Trays |0-25 |40-100 |
Measures were also taken to ensure adequate air movement around plants. Those grown under cover were grown under ventilated glasshouses or polytunnels where doors and side vents were kept open to increase air movement. Some glasshouses had fans and their usage ranged from being on all the time to providing additional air movement as necessary; two growers made use of fans during cold weather when the vents were closed to provide air movement. Gravel was also used as a base to improve drainage and increase air movement, particularly in larger pots.
Production techniques
Various production techniques were used:
• Cordyline australis 'Red Star' and 'Sundance' were purchased as plugs and potted into 1 L.
• Phormium plugs were potted to 1 L then sold; liners to 3 L then sold; 3 L to 7.5 L then sold
• Machine potted into 3 L, set down, cleaned once, labelled.
• Cordylines were bought in as plugs (C. ‘Red Star. and C. australis) and liners (C. ‘Torbay Dazzler’, C. ‘Southern Splendour’) and grown on into 3 L plants and sold.
Both Cordyline and Phormium were generally planted to a depth of 0.2 to 1.0 cm, however there was some variation:
• Cordyline in 30 L pots were planted 15-30 cm below the surface to stabilise them and encourage rooting from the stem, thereby avoiding ‘wobble’ or ‘rocking’. Rocking was reported by one grower to affect 5-10% of the crop. One grower found that this condition did not seem to affect C. ‘Torbay Dazzler’. Cordyline plugs were also planted deeper to prevent rock (there are implications with this encouraging crown rot). It is critical that the growing point is not buried.
• 10 L Phormium were not planted deeper than the original 3L pot to prevent the growing point from being lost.
• Planting to slightly below the crown to avoid rock for both Cordyline and Phormium.
Liners and plugs were carried in trays, and larger plants were generally handled by the pot. Potting was carried out by machine with plants held by the root ball, except for those in 30 L pots which were hand potted. However, some growers did allow established 3 L pots to be handled by the tops. Less handling problems were experienced with Phormiums than Cordylines, however they were still predominately handled by the pot.
A particular issue had been noticed with Cordyline ‘Torbay Dazzler’. It was suspected that handling by the tops caused damage to the leaf margins of young plants, seen as browning of the leaf margins in older plants and they were therefore handled by the pot only.
Protection
Cordyline and Phormium were grown under protection to increase growth, thereby reducing production time, and under glass in preference to plastic.
Two nurseries did not provide any heating to the crop, although one of these did heat the work station within the glasshouse. Four growers used gas, three used oil and one used both gas and oil in different areas. One grower provided under floor heating to 160C in the propagation area and frost protection to 20C for the rest of the glasshouse. No fume-related problems to the crop were noted, even though four growers vented their boilers inside. Heating costs were an issue noted by three growers, with one standing plants pot thick during the winter to save space and retain heat.
Irrigation
For both Phormium and Cordyline the predominant irrigation systems used were overhead sprinklers (eight growers) and Efford sand beds (two growers) with some supplementary hand watering (three growers). The overhead irrigation systems used pin jet nozzles, anvil nozzles, rotoframe sprinklers and micronozzles. Irrigation systems were mainly installed within the last 5 years, although three were over ten years old. Mains water was the major water source used (Table 21). Three of the eight nurseries had tested the performance of their irrigation system (for example as described in HDC Factsheet 16/05). Typical corrective action taken was to adjust the layout of plants to avoid dry spots.
Table 21. Water sources used by growers.
| |Borehole |Reservoir |Mains |Roof |Bed |
| | | | |run-off |run-off |
|Propagation area |1 |0 |3 |1 |0 |
|Other protected |3 |1 |5 |2 |0 |
|Outside |2 |0 |0 |0 |0 |
Five nurseries, those that used borehole, run-off and reservoir water (one exception) had systems in place to clean their water:
• Aeration to remove iron
• Mains acidified with nitric acid, and reservoir water chlorinated to 5 ppm. 3 stage filtration:
o vortex filter (grit and sand)
o chlorination
o high pressure sand filter removing particles about 100 μm
• Mesh filter
• Ozone and stored in covered tanks
• In-line filter from tank to pump
Growers used various techniques to decide when to apply irrigation. All nurseries manually checked pots and used this information in conjunction with weather conditions and forecasts. A computer controlled system was also used by one nursery to apply water little and often early in the morning.
Growers ran predominately dry regimes. Cordyline were kept dry, and more so during the autumn and winter. Phormium were kept slightly wetter than Cordyline; two nurseries watered Phormium heavily at first and then allowed them to dry back. Water regulation was also used to combat spider mite with heavier applications during hot summer conditions.
In general, little liverwort was found on these nurseries. Infestations tended to be localised, for example due to a leaky roof, unlevel beds where water collected and by the doors in winter where moisture was able to dampen growing media. A high standard of nursery hygiene was maintained with beds and surroundings cleaned with Jet 5 between batches. A mix of Fungex and Majestik was used after potting on one nursery, but the effect of this was not clear.
Various different bed constructions were in use (Table 22). Improved drainage through bed construction would help to reduce root and crown diseases and also liverwort infestation.
Table 22. Bed construction.
|Bed construction |No. growers |
|Sandbed |1 |
|Efford sandbed with growtech cover |1 |
|Capillary matting over polystyrene (benches) |1 |
|Mypex over gravel/slate waste |2 |
|Mypex over polythene, on a slope |1 |
|Gravel |1 |
|Mypex over soil |3 |
Growing media
A range of ingredients were used in growing media (Table 23) with growers typically using two to three grades of peat to obtain the required texture. Consideration was being given to including approximately 15% PAS 100 certified green compost in the future by some growers. Mulches used included one grower using bark with iron sulphate to feed plants and this was also thought to help combat moss and liverwort growth.
Table 23. Growing media components used for Cordyline and Phormium crops.
| |No. growers |% |
|Bark |6 |10-50% |
|Humic compost |1 |10 |
|Perlite |1 |10 |
|Coir |1 |40 |
|Peat |8 |50-85% |
|Woodfibre (Toresa, Kokos) |2 |20-30% |
|Wetter |2 |- |
|Mulch (bark, coir) |2 |- |
Five of the growers routinely had their growing media analysed, and four retained samples of used growing media; growing media producers (Treff and Scotts) also kept samples. pH ranged between 4.5 and 6.5. Some growers incorporated pesticides such as Intercept 70 WG (1 grower), ViNil (1 grower) and Exemptor (1 grower). The air filled porosity of growing media was tested by two growers (15 % and 18-25%) and particle analysis was not typically carried out.
6 Nutrition
Table 24. Nutrients applied to Cordyline and Phormium crops.
|Product |Formulation |Quantity |
|Base fertiliser | | |
|PG-mix |15:10:20 |0.5 to 1 kg/m3 |
|Micromax (trace elements) 16-18 months | |0.25 kg/m3 |
|Treff Base Fertiliser (TBF) High N |17:10:14 |1 kg/m3 |
|Scotts Osmocote Start 6 weeks |12:11:17 + MgO + trace elements | |
|Vitafeed 1:1:1*** |19:19:19 + trace elements |1 g/L at 1% |
|Controlled release fertiliser (CRF) | | |
|Osmocote Exact std prill size12-14 month |17:10:10 |3 kg/m3 |
|Sinclair Sincrocell 10-12 months |14:08:13 |4 kg/m3 |
|Osmocote 12-14 month |17:10:10 |3 to 3.5 kg/m3 |
|Osmocote 3-4 month* |18:10:11 + 2MgO + trace elements|plug |
|Osmocote pro 12-14 month |17:10:10 |3.5 kg/m3 |
|Osmocote Standard 8-9 months (1-2 L mix) |15:09:11 |2 to 4.5 kg/m3 |
|Liquid feed | | |
|Peters Excel (Cordyline australis)*** |18:10:18 + 2MgO |1 g/L at 1% |
|Peters professional** |1:1:1 | |
|Spot feed | | |
|Other | | |
|Lime | |2.5 kg/m3 |
|Wetter | |0.4 L/m3 |
|Nitrochalk | |0.2 kg/m3 |
|Fritted trace elements |255 |0.3 kg/m3 |
*added to 3L pots before potting on to ensure the core has enough nutrients to push roots out. **throughout the growing season. ***weekly.
Growers provided details of the fertilisers applied to their Cordyline and Phormium crops (Table 24). Most growers used a base fertiliser with controlled release fertiliser (CRF). Two growers applied BioFungus Instant to their crop. Three growers routinely applied compost tea and another was about to start (Table 25).
Table 25. Details of compost tea systems in use.
|Product |Compost Tea |
|Supplier |Fargro and Van Lersel biezenmortel Tilburg NL. |
|Brewing method |Xtractor |
|Application regime |Typically applied via irrigation lines and knapsack sprayers at approximately 2-weekly |
| |intervals. |
|Other relevant information |One grower applied Maxicrop along with Compost Tea |
Pests, diseases, disorders and quality
Growers provided details of pests, diseases, disorders and quality issues found experienced with Cordyline and Phormium crops.
Mealybug
Two growers had found mealybug on Cordyline, treating it with Conserve and Calypso at the recommended rate when first seen. Imidasect 5 GR and Exemptor were used at potting by another grower to prevent infestation.
Mealybug was one of the major pest problems of Phormium (Figure 2) as it is difficult to control (Jones, 2008). It was found more often on older plants, and on the P. tenax, P. ‘Maori Maiden’ (a weaker variety) and P. ‘Platt’s Black’. It was often brought into the nursery on the crop and numbers built up in the autumn. Control measures used were Dimethoate 40, Chess (at the higher rate under SOLA 2834/08), Gazelle, Gyro, Decis, Calypso with applications made when the mealybug was first seen and then 2-3 times per season. Growing media-incorporated products Exemptor (280 g/m3) and Intercept 70WG were used at potting for both liners and final pots by three of the growers. One grower also washed down with Gazelle.
|[pic] |
Figure 2 Phormium infested with mealybug (Dan Drakes, 2009)
Thrips
One grower had experienced problems with thrips on Cordyline, but none were reported on Phormium. The control measure used was Conserve applied at the recommended rate when present during the spring and summer.
Slugs
Three growers had experienced slug problems on all varieties of Cordyline, and one had a particular problem on small plants of C. ‘Red Star’. Regular treatments of Ferramol, metaldehyde pellets and Nemaslug were made. Croptex Fungex (approved only as a fungicide) copper fungicide was also used (2.5 ml/L) to remove slugs from foliage.
Two-spotted spider mite
All growers except one had problems with two-spotted mite and for some this was a major pest of both Cordyline and Phormium. Susceptibility was not considered to be varietal, although one grower tended to have more problems on C. a. ‘Torbay Dazzler’, and for one grower severity of infestation was dependant on time of year and plant condition. Varieties of Phormium affected were P. Pink Stripe, P. Yellow Wave’, P cookianum ‘Flamingo’, P. ‘Maori Maiden’, P. ‘Maori Queen’, P. ‘Maori Sunrise’, P. ‘Sunset’ and P. ‘Golden Ray’
Chemical control measures used were Floramite 240 SC, Gyro, Dynamec, Apollo 50 SC, Masai, Majestik and regular applications of SB Plant Invigorator. Fogging with Dynamec and Apollo 50 SC had been used but as it is difficult to penetrate the leaf structure this application method was less successful than a heavy wet spray. Applications of Dynamec prior to plants leaving the nursery were used to prevent carrying two-spotted mites to the customer. Biological controls were used with some success using Phytoseiulus persimilis, Amblyseius californicus and Feltiella acarisuga, however there are reports of growers having difficulty in adequately establishing the predators (Buxton, 2009).
Aphids
Three growers had experienced infestations of aphid, on all varieties and growth stages of Cordyline; no aphids were reported on Phormium. Both chemical (Chess, Aphox and Spruzit) and biological controls (Aphidoletes aphidimyza and Aphidius colemani) were used with success. Aphids were not considered a major pest of Cordyline or Phormium.
Caterpillars
Tortrix caterpillars had been found on both Cordyine and Phormium by two growers. They were treated using Conserve and Gazelle and also the biological control Bacillus thuringiensis (Dipel DF).
Sciarid fly larvae
One grower reported sciarid fly larva on Phormium which they treated with application of large populations of Atheta coriaria from their own breeding colonies during propagation.
Undiagnosed yellow leaf spots
There is some confusion regarding yellow leaf spots and oedema; laboratories have attributed some yellow leaf spots to oedema and some growers may have incorrectly categorised the condition found in their crops.
Yellow leaf spots were found on five of the nurseries, primarily on C. australis and not on variegated or purple forms, however one grower did report finding them on C. ‘Sunrise’. Two growers reported finding yellow leaf spots on Phormium but fungicides were not an effective treatment and one grower destroyed affected plants to remove the threat to the remainder of the crop. These yellow spots seemed to appear when plants were short of nutrients or otherwise under stress, with incidence varying each year. Chemical treatments used were Amistar, Systhane 20 EW and SB Plant Invigorator. Cultural methods such as attention to irrigation, adequate ventilation and heavy applications nitrogen fertiliser were also used.
Oedema
Yellow spots indicative of oedema (Figure 1) and similar to that found in Eucalyptus, only affected Cordyline. All cultivars, but notably C. ‘Red Star’, were affected. Seed raised plants, larger plants and older leaves were all found to have this condition. Cultural measures such as adequate ventilation, spacing and warmth all helped to reduce oedema. Control of pest and disease was thought to be beneficial, as did regular application of SB Plant Invigorator and compost tea. It was reported that oedema did not kill plants and they could grow on to be healthy. This condition is reported to appear at certain times of the year when roots are saturated and wet, often during the transition period between winter and spring, and often growing out of it during the summer. It has been found more often in younger plants and some varieties seem more susceptible than others (Jones, 2008).
Other leaf spots
Individual growers reported the following leaf spots:
Brown markings were reported on the leaf edge of medium aged Cordyline leaves only, not new leaves in one nursery. Herbicide damage and scorch had been discounted as causes. Plant handling practices were changed, so they were no longer handled by the tops and this appeared to have solved the problem.
Black lesions at the base of Phormium had been identified as Colletotrichum or Fusarium. P. ‘Apricot Queen’ and ‘Sundowner’ were affected; on another nursery Colletotrichum had been confirmed affecting P. ‘Yellow Wave’ and some pink varieties (Figure 3a). A mix of Delsene 50 Flo (carbendazim, no longer approved for use on ornamentals) and Bravo 500 had provided some control in both cases.
Pin-prick brown spots on Phormium leaves were controlled using fungicidal treatments at 14 day intervals throughout the winter, the spray programme including Octave, Repulse, Subdue and Amistar.
|a |[pic] |B |[pic] |
| | | | |
Figure 3(a) Phormium with suspected Colletotrichum leaf spot (England, 2007) (b) Cordyline with tip burn (Gray, 2009).
Tip burn
Tip burn, or leaf tipping (Figure 3b), was more of a problem with Cordyline, but still of note in Phormium. Purple Cordyline varieties, C. ‘Torbay Dazzler’, C. ‘Sunrise’, C. Red Star’ and C. ‘Firecracker’ were affected and the condition was considered varietal by some growers. One grower reported that tip burn had been successfully eliminated from stocks of C. ‘Red Star’ (along with a range of foliar and root problems). A reliable form of C. ‘Red Star’, showing no symptoms of tip burn, had been created using tissue culture techniques, by taking a single initiation from a single selection and then increasing stock levels, suggesting that a virus may be a cause. The condition had been put down to calcium deficiency and humidity by other growers. Although this was a major problem to growers no other control measures were used.
Leaf bleaching
Two growers reported leaf bleaching. Cordyline ‘Southern Splendour’ had bleaching to the back of the leaf tips; it was thought that this may develop into tip burn. No action was taken as the cause was unknown.
Phormium ‘Jester’ had shown a general all-over paleness and bleaching, which may have been caused by two-spotted spider mite damage at a young age.
Stem / crown rot
Five growers reported stem and crown rot problems in varying degrees in Cordyline. Over a period of 10 years, one grower had experienced loss of the terminal shoot on a low percentage of Cordyline liners which had been micro-propagated and grown in agar. In one nursery this had been reported as Fusarium by the laboratory and the disease had been controlled using carbendazim (no longer approved). In another nursery, Pythium and Phytophthora had been confirmed in liners with poor roots. Another grower had seen this condition in Cordyline ‘Sundance’ and had stopped growing that variety. Where incidence was small plants were not treated, however Subdue, Proplant and Aliette 80 WG were all used by other growers; attention to watering to avoid wet foliage also helped to reduce infection. In Phormium, stem and root rot was attributed by some growers to over-deep planting, and the solution was to plant less deeply. Crown rot caused by Colletrotrichum was found on Phormium plants which had been weakened by red spider mite although Colletotrichum is more commonly found as a leaf spot pathogen rather than crown rot. Rhizoctonia solani had been found 7 years ago in the propagation area of one nursery, in plants that had been divided. This problem had not been found again since using compost tea. Cultivars affected were Phormium cookianum cvs ‘Evening Glow’, ‘Flamingo’, ‘Jester’, ‘Maori Maiden’, ‘Maori Sunrise’, ‘Pink Stripe’, ‘Sunset’ and ‘Golden Ray’. Those least affected were P. ‘Sundowner’, ‘Gold Sword’ and ‘Yellow Wave’. Basilex (2.0 g/m2) and Rovral WG (1.5 ml/m2) were used to control the disease.
Root rot
Violet root rot caused by Helicobasidion purpurea was observed on a small number of Cordyline, and identified by John Adlam a few years ago. Other root rots were found on C. ‘Red Star’ and C. ‘Sundance’, and young plants in general. Some growers thought that certain varieties were particularly susceptible.
Phormium suffered from root rots during the winter when they had been kept too dry for too long and then watered; maintaining damper growing media at all times allowed some growers to avoid this problem.
Cordyline 'wobble' or ‘rock’
This was a major problem affecting around 5% of one grower’s crop. It occurred in C. ‘Torbay Dazzler’, C. ‘Red Star’ and C. ‘Sundance’, and plants were unstable, not standing firmly upright. Historically, this condition had been attributed to the material around Elle Plugs being too dense for plants to root through, however this issue had since been addressed by the manufacturer and the condition still occured. One grower had observed that Cordyline root downwards first, then produce lateral roots which stabilise the plant. Other factors thought to contribute were over-wet growing media, lack of roots, top heavy plants and roots dying back in winter. Solutions used were to leave growing media bone dry and plant larger plants (30 L) deeply to avoid this condition. Some growers had stopped producing affected varieties. Other steps taken by growers were to grow Cordyline outside to allow wind rock to encourage plants to produce more roots to add stability.
Other problems affecting Cordyline and Phormium
• Collapse had been observed in C. ‘Sunrise’ plants following a period where the crop had been maintained dry, almost to wilting point and then watered. Subsequent leaf spotting was suspected to be Fusarium although this was not confirmed.
• P. ‘Alison Blackman’ was considered less robust than some varieties and suffered from several conditions, including collar damage (due to frost forming at the top of the growing media), root damage (this was less of a problem if plants were potted later when more vigorous) and tip damage (due to cold temperatures).
• The relatively lax P. cookeriana cultivars such as ‘Cream Delight’ and P. ‘Pink Stripe’ developed bruising (Figure 4a) and holes in leaves where they bend over (found in batches from tissue culture only). This condition occurred more often during winter and at one nursery. More upright varieties such as P. tenax were less affected.
• Botrytis had been found in new Cordyline plugs and was successfully treated with fungicide.
• A concertina effect (Figure 4b) was noted on some Phormium leaves, but no action was taken as the cause was not established.
|a |[pic] |b |[pic] |
Figure 4 Phormium with (a) bruising (b) crinkly leaves (England, 2007).
Some growers had spray programmes in place to minimise incidence of pest and disease and weeds (Table 26) where possible:
• Protective Delsene 50 Flo (no longer approved for use on ornamentals) and mixed with Bravo 500, and possibly Octave in autumn (Phormium).
• Compost tea plus maxicrop (seaweed) is applied at regular 14 (outside crops) and 7 (protected crops) day intervals (Cordyline and Phormiium).
• Standon Fullstop drench (after transplant), Amistar (one week post transplant), Plover (four weeks later) and Systhane 20EW (four weeks after transplant) (Cordyline and Phormiium).
• Slug and snail control regularly applied through high rainfall and wet summers.
• Octave, Bravo 500 / Repulse, Rovral WG, Fungex Croptex / Majestic mix alternated (against Cordyline and Phormium).
Plant samples had been analysed for disease by growers, with Pythium, Phytophthora and Fusarium identified on Cordyline, and Colletotrichum and Phytophthora found on Phormium.
Table 26. Herbicides applied to Cordyline and Phormium.
|Herbicide |Timing |Rate |
|Ronstar granules |After potting (all crops). |Label |
|Jet 5* |Bed preparation. |Label |
|Flexidor |Applied to Phormium during September / October, after |Double |
| |transplant and 6 wks later. |Label |
| | |1 L/ha |
|Glyphosate |Bed preparation, prior to standing down. |Label |
|Hortisept* |Bed preparation |Label |
|None (sensitive crop) | | |
* Jet 5 and Hortisept are not herbicides
As in the initial survey, growers were asked to comment on future Cordyline or Phormium crop research. The comments made by growers are quoted below:
• “Poor rooting at the top of the pot in Cordyline may be due to high salt conductivity in the top layer of compost, and tests on the compost have shown this to be the case. This may be due to the watering method (sub-irrigated sand beds) which can give a gradient of moisture in the pot and lead to heavier rooting at the base. On the positive side, sand beds do give good drainage and the foliage is very clean. The lack of rooting by the scaffold roots at the top of the pot is a severe problem for the nursery and they are considering doing some overhead watering to flush through the excess salts.”
• “Yellow spotting (Cordyline)”.
• “Tip burn”.
• “Mealybug control”.
• “Leaf tipping”.
• Two-spotted mite (TSM). “As growers we rely on acaricides to control TSM as it is very difficult to integrate IPM into Phormium crops. Currently there are no traps to catch them. When damage is seen it is too late to spray effectively. Early on, top growth is sparse and most of the IPM controls cannot search for TSM easily and efficiently. Crops are difficult to spray even when maturing and seemingly offer a better target. Some Phormium cultivars have what growers term 'umbrella foliage' where the leaf rolls over like the underside of an umbrella and where the mites can multiply under the hot succulent leaf. Moderate spells of warm summer weather (viz. the cloudy, wet 2007/8 summers) lead to very rapid increases in mite populations. The pest lives on the underside of the foliage and it is extremely difficult to obtain good coverage using acaricides following rapid growth. Further work is required into being confident that growers can target the source of the pest early in the growing season”.
• “Oedema requires further study to ascertain the actual temperatures, RH, water deficit and water logging parameters which can stress these plants”.
Pest and disease analysis report
Eight whole Cordyline plants, with yellow leaf spots, were submitted to FERA's plant clinic for detailed analysis. A thorough visual examination was performed checking all parts of the plants including root and stem base health in addition to any leaf spots or foliar blight. Samples were tested by incubation and isolation for fungal pathogens, isolation for bacterial pathogens, ELISA for three common viruses and by electron microscopy (Table 27). If any visual evidence of pest damage was observed, samples were passed to entomologists for an expert opinion. Transverse sections were also cut through representative samples and the ultrastructure of the leaves examined. In addition to this one representative sample was tested using a novel diagnostic molecular technique called genomics or ‘pyrosequencing’.
Table 27. Summary of test results for Cordyline samples sent to FERA Plant Clinic
|CSL Ref |Entomology |Bacteriology |Virology |Mycology |
|20906124 |Negative |Negative |Negative |Negative |
|20906125 |Negative |Negative |Negative |Negative |
|20906484 |Caterpillar |Negative |Negative |Negative |
|20906486 |Red Spider Mite (found |Negative |Positive |Negative |
| |in 2 samples) | | | |
|20906487 |Negative |Negative |Negative |Negative |
|20906488 |Negative |Negative |Positive |Negative |
|20906502 |Negative |Negative |Negative |Negative |
|20907349 |Negative |Negative |Negative |Negative |
Virology
Cordyline samples tested negative (by ELISA) for Tomato Spotted Wilt Virus, Impatiens necrotic spot virus and Cucumber Mosaic Virus, but for samples 20906486 and 20906488 low levels of rod-like virus particles were seen in sections. Determining the significance of these particles fall outside the scope of this project but could warrant further investigation. However, the inconsistency of their presence and the low levels of reserves do not provide firm evidence of an underlying viral problem.
Bacteriology
No primary plant pathogenic bacteria were detected.
Mycology
Cladosporium was predominantly isolated, in addition to Botrytis and Trichoderma. A simple pathogenicity test (Table 28) was performed with a representative culture of Cladosporium and Botrytis. Sporulating agar plugs were placed aseptically onto sterilised unwounded and wounded detached purple and green leaves with negative controls.
Table 28. Results of pathogenicity tests.
| |Un-wounded |Wounded |
|Cladosporium |Negative |Slight necrosis |
|Botrytis |Slight necrosis |Necrotic lesion |
|Control |Negative |Slight necrosis |
These results indicate that the Cladosporium was not a primary pathogen, supporting earlier pathogenicity testing previously completed, and in line with the general perception that this organism is a common saprophyte. Not surprisingly the Botrytis was able to cause some necrosis especially when the plant had been wounded.
Ultrastructure analysis
A number of representative samples of the leaf spot syndrome were sectioned and examined under a high-power microscope. Swollen cells, below the epidermis, typical of oedema were observed. Oedema is a physiological problem thought to occur due to water relations imbalance commonly occurring during periods of high water availability and high humidity. Oedema occurs when roots take up water faster than it can be used by the plant or transpired through the leaves. Water pressure then builds up in the mesophyll or internal cells of the leaf causing them to enlarge and form tiny swollen blister-like areas. This results in a swelling of these cells commonly leading to chlorotic leaf spots. Under certain conditions the cells may burst leading to a necrotic spot. Oedema is most prevalent in the late winter especially during extended periods of cool, cloudy weather. It is likely to develop when the soil is warm and moist and the air is cool and moist. This environment results in rapid water absorption from the soil and slow water loss from the leaves. Overwatering, high humidity, and low light intensities are factors that favour the development of oedema.
Advanced molecular testing
Samples were tested by Dr Ian Adam and Rachel Glover of FERA investigating advanced molecular diagnostic techniques (as part of a Defra-funded project). The DNA of a representative sample of symptomatic and non-symptomatic Cordyline leaves was sequenced. By comparison of the sequences produced it was possible to look at any DNA differences between the two samples and to identify whether any other organisms were present. No such differences were found. Although not replicated, this relatively novel technology does support the theory that pest or disease was not present or implicated.
Discussion
A number of problems have been identified from this study that warrant further analysis and discussion to try to understand if there are any common measures taken or husbandry techniques used by growers that exacerbate or provide some control. In the initial survey growers were asked to quantify the cost of pests and diseases to their business, but this was not easy and many were unable to provide a figure.
Pests
Phormium mealybug
The initial survey indicated that Phormium mealybug was not a major problem on Cordyline, however it did affect 19 Phormium growers with the value of the damage to crops in excess of £250,000 in total; seven of the nurseries participating in the case study were affected. The only biological control available (Cryptolaemus montrouzieri) provided poor control and opinion was mixed regarding the effectiveness of chemical products with the majority falling into both the ‘good’ and ‘moderate’ categories. Products ranged from ‘soft’ chemicals such as spraying oil and SB plant invigorator to Temik 10G (no longer approved, aldicarb, carbamate) and Dursban (chlorpyrifos, organophosphate). Only one grower did not have mealybug and the pest had been absent from the nursery for a number of years. Other pest controls applied to the crop by this grower were acaricides, SB Plant Invigorator, Bacillus thuringiensis (Dipel DF) (against tortrix caterpillar), Ferramol and Croptex Fungex (against slugs and snails), Atheta coriaria (own colonies, against sciarid fly larvae); there were no thrips or aphid on the crop.
Slugs and Snails
Slugs and snails did cause problems for growers, affecting Phormium more than Cordyline, the cost of which was not provided. However, there was a range of control options available all of which provided good control. The biological control Nemaslug was used by two growers and proved effective.
Two-spotted spider mite
No value was registered for damage due to two-spotted spider mite. However, 19 growers reported infestations on Cordyline and 20 on Phormium in the initial survey; all 8 on Cordyline and 7 on Phormium in the case studies. This was considered to be a major problem. A wide range of acaricides and biological controls were available which were considered to provide good control. However, the difficulties facing growers in controlling this pest were well described by one grower (refer to pages 36 and 52), and there may be difficulty in adequately establishing the biological controls (refer to page 46). The grower that did not have two-spotted spider mite on his Phormium did have it on his Cordyline which he treated successfully with Floramite 240 SC (bifenazate). However, Dimethoate 40 (dimethoate, organophosphate), which has a label recommendation for use against red spider mite in ornamental plant production was applied to the Phormium aiming to control mealybug.
Aphid
Aphid was only reported on Cordyline, by five growers in the initial survey and three in the case studies. Of these, three had applied a value to the crop affected. A range of biological and chemical controls are available, and it was considered that these provided good control. Aphid was not considered a major problem.
Thrips
Thrips was not a serious problem, affecting three Cordyline and four Phormium growers in the initial survey and one grower in the case study (on Phormium).
Tortrix caterpillar
Tortrix caterpillar was found on both Cordyline and Phormium by two growers and was considered less of a problem.
Vine weevil
Vine weevil was a problem on Cordyline for one grower who responded to the initial survey, but to no growers in the case studies; moderate control was obtained using Cyren (Chlorpyrifos) and nematodes.
Sciarid fly
Sciarid fly larvae were also a problem for one grower who took part in the case studies, and these were controlled using rove beetle Atheta coriaria.
Diseases
Yellow leaf spot / oedema
Yellow leaf spot syndrome and oedema are considered together within the discussion as it is possible that growers refer to this condition by either name as there is confusion within the industry. Nineteen growers recorded yellow leaf spot on Cordyline (£119,437), three of which also recorded oedema (an additional £50,000); five recorded yellow leaf spot on Phormium (£3,375) but no oedema. In the case studies six growers had this problem on Cordyline and two on Phormium. The analysis carried out by FERA found red spider mite on two plant samples, low levels of an unidentified rod-like virus on two samples and secondary fungal pathogens; however, there was some evidence of oedema affecting a number of samples. A number of grower comments were received regarding leaf spots (refer to pages 36 and 52).
Two of the nurseries that took part in the case studies and did not have a problem with yellow leaf spot / oedema were considered further:
• Neither provided greater spacing between pots than the other nurseries and one placed plants pot thick during the winter (oedema often appears in late winter). Neither of these nurseries used fans, additional venting or other techniques to improve ventilation.
• One applied no heating; the other had propane heating vented outside. Other growers who did have yellow leaf spot also used propane heating or applied no heating.
• Both nurseries had overhead irrigation systems, supplementing with hand watering, and they used mains water for their propagation area or smaller pots, and reservoir or borehole water for larger pots. One (using reservoir water) had no systems in place to clean their water including filters whilst the other (using borehole water) used ozone treatment and stored water in covered tanks. Other growers with similar systems had yellow leaf spot.
• Irrigation decisions were based on weather conditions and manual checking, and both ran ‘dry’ regimes as evidenced by a general lack of liverwort in common with other growers. Bed construction was mypex over soil on the ground and capillary matting over polystyrene on benches in one nursery, and well drained gravel beds in the other.
• Growing media formulation for both nurseries was predominately graded peat with 20% Toresa woodfibre, 10% bark in one nursery and 33% bark in the other, with pH 4.5 – 5.5 for both. One nursery incorporated Exemptor (imidacloprid) in the growing media. Other growers used comparable proportions of bark or woodfibre. A range of nutrients were used by growers, predominately base fertililiser, CRFs and liquid feed.
• Neither used growth stimulants (e.g. Bio Fungus); but one used compost tea and the other did not.
None of these responses to the questions posed in the case study suggest that these factors contribute to the lack of yellow leaf spotting and they do not differ greatly from the other nurseries.
SB Plant Invigorator was used routinely by one grower who treated the whole crop via the irrigation lines and also soaked all plants in a solution for 1 hour prior to potting. Although this treatment was considered successful in managing yellow leaf spot syndrome, both Phormium mealybug and two-spotted mite were ongoing problems and it was costly.
Other leaf spots
Other leaf spots were also costly to growers, with eight growers registering problems with Cordyline, and six with Phormium in the initial survey. The total value of the damage caused to Cordyline and Phormium crops was £72,250. Only one grower reported that a sample had been analysed and the pathogen had been identified as Colletotrichum. To minimise leaf spots growers may need to adjust their water management in terms of application timing and / or method and ensure the cause is correctly diagnosed by laboratory analysis so that the appropriate control measures may be applied.
Tip burn
In the initial survey ten growers registered problems with tip burn in Cordyline and six in Phormium. The total value of the crops affected was £1,075,350. In the case studies five growers experienced problems with Cordyline and two with Phormium; none of them applied any treatments as they did not know the cause of the condition, although one grower suspected calcium deficiency. From the initial survey, treatments used by other growers included water management, calcium supplements, foliar feeding, site selection (fluoride level in water) and temperature, all of which were considered to have a beneficial effect; humidity control does not appear to have helped.
There is a strong suggestion from the literature that fluoride toxicity may be involved, with reports that Cordyline and Phormium are sensitive to fluoride. It is not clear, however, if that includes those varieties grown in the UK, what level (if any) would produce an adverse effect, and if the nurseries that experience this problem have particularly high levels of fluoride in their water. General water authority information suggests that mains water supplied to these nurseries should be below the level that would cause problems in general (1.0 mg L-1) and levels in river water are well below that (British Geological Survey, 2005). Bunt (1988) recommended avoiding irrigating crops with water with greater than 0.25 mg L-1 fluoride. Fluoride levels are not commonly included in water analyses and this information would be required to obtain a precise answer. Growing media pH above 6.0 to 6.5 has been recommended, but nurseries No. 2 and No. 6 have their pH within that range and still have tip burn. Calcium and / or potassium deficiency may also be involved. This condition appears to have been eradicated from stock of C. ’Red Star’ using tissue culture techniques and this route may be worth considering for high throughput varieties such as C. australis and C. ‘Torbay Dazzler’. A number of growers commented on tip burn (refer to pages 36 and 52).
‘Wobble’
Growers were not asked specifically about Cordyline 'wobble' or ‘rock’, although through discussions it was found to be a serious problem to growers. Some growers considered that planting depth and growing media management play a large part in controlling this problem. Grower comments were received relating to this issue pages 36 and 52).
Crown, stem and root rots
Crown, stem and root rots were estimated to cost growers a total of £28,664 (Cordyline) and £222,534 (Phormium) in the initial survey. Pathogens implicated were Phytophthora, Pythium and Fusarium. In the case studies, four growers experienced these problems with Cordyline and six with Phormium. Altering planting depth and changing irrigation practices had helped some growers to combat these problems. It is well documented that wet growing conditions contribute to proliferation of the fungal pathogens, predominately oomycetes, that cause these diseases, and careful management of irrigation regime, drainage and growing media formulation can help to control them. Grower comments were received relating to this issue pages 36 and 52).
Conclusions
Pests, diseases and disorders or Cordyline and Phormium were investigated through a literature review, survey of growers, case studies and laboratory analyses. This report identifies a number of areas which warrant further investigation, aiming to establish a definitive cause and practical solution to major problems being experienced in Cordyline and Phormium production: Phormium mealybug, two-spotted spider mite and the undiagnosed conditions yellow leaf spot syndrome, tip burn and ‘wobble’.
Further investigation into the control of Phormium mealybug may include further evaluation of pesticide options currently available, including better and cost effective use of ‘soft’ chemicals such as SB Plant Invigorator as this product is being used with some success. Biological controls are limited, but an investigation of wild Phormium in their native New Zealand could identify natural predators and parasitoids which could be studied as potential controls for the future.
There are a number of biological controls and acaricides available for two-spotted mite; growers are making good use of biological controls, however the success rate is reportedly poor due to difficulties in establishing predators, resulting in a poor return on their investment.
Yellow leaf spot syndrome appears to be a physiological problem however plant tissue analysis has indicated presence of an unidentified virus in a small number of samples. Investigations could involve further analysis to establish if the small sample investigated in this study is representative of distribution across the industry and aim to identify the virus. It would be of interest to monitor growing conditions and the environment when these spots first appear on new plants, for comparison. Physiological aspects could be investigated using growth cabinet and nursery trials to establish best practice to prevent occurrence.
Tip burn affects the crops of many growers, and no clear cause has been established through this survey. Growers do not treat these symptoms as they have no diagnosis. Further research is required to identify the cause and devise best practice advice for nurseries to improve crop quality. This could involve nutrient feeding trials, investigation of fluoride levels in water sources, analysis of plant samples to establish if a virus is involved, and / or selection and tissue culture of less prone stock of key varieties.
Further investigation of planting depth, growing media and water management could provide growers with best practice guidelines to address Cordyline 'wobble' or ‘rock’, stem, root and collar rots.
References
Aenderkerk, T. 1997. Fertiliation guide for nursery crops. The Netherlands, Boomteelt Praktijkonderzoek.
Andersen, M.T., Beever, R.E., Sutherland, P.W., & Forster, R.L.S. 2001. Association of "Candidatus Phytoplasma australiense" with sudden decline of cabbage tree in New Zealand. Plant Disease, 85, (5) 462-469
Armitage, J., Cubey, J., Grant, M., Lancaster, N., & Whitehouse, C. 2005. RHS Plantfinder 2005-2006. Eighteenth. London, Dorling Kindersley.
Bartlett, P.W. 1981. Trionymus diminutus (Leonardi) (Homoptera: Pseudococcidae) infesting New Zealand flax in England. Plant Pathology, 30, 56-58
BCP Certis. 2006. BCP Certis. Biological controls. Mealybug control. Certis. Available at: . Accessed: 11 November 2008.
Bennison, J. & Schüder, I. 2006, HNS 105 DEFRA HH1944TFV Hardy nursery stock: integrated control of snails and slugs, Horticultural Development Council and DEFRA, East Malling.
Bould, C., Hewitt, E.J., & Needham, P. 1983. Diagnosis of mineral disorders in plants. Volume 1. Principles. London, Her Majesty's Stationery Office.
Bragg, N. 1998. Grower handbook 1. Growing media Kent, Nexus Media Ltd.
Brennan, E.G., Leone, I.A., & Daines, R.H. 1950. Fluorine toxicity in tomato as modified by alterations in the nitrogen, calcium and phosphorus nutrition of the plant. New Jersey Agricultural Experiment Station 736-747
British Geological Survey. 2005. British Geological Survey. Land quality and ground water - fluoride in stream water. British Geological Survey. Available at: . Accessed: 9.04.2009.
Buczacki, S. & Harris, K. 2005. Pests, diseases & disorders of garden plants, 3 ed. London, HarperCollins.
Bunt, A.C. 1988. Media and mixes for container-grown plants, 2nd ed. London, Unwin Hyman.
Buxton, J. 2009, Factsheet 12/09. The biology and control of mites in pot and bedding plants., Horticultural Development Company, East Malling.
Conover, C.A. & Poole, R.T. 1971. Influence of fluoride on foliar necrosis of Cordyline terminalis cv Baby Doll during propagation. Florida Agricultural Experiment Stations Journal Series, No. 4083, 380-383
Copland, M. 2008. Wye Bugs, Wye, Ashford, Kent.
Croft, P. 2007, PC 215 Tomatoes: further development of sustainable mealybug control strategies, Horticultural Development Council, East Malling.
Crous, F., Ferreira, A., & Sutton, B. 1997. Phaeophleospora phormii (Naito). South African Journal of Botany, 63, (3) 115
Dan Drakes. 2009. ADAS (UK) Ltd.
Davison, A.W., Marsland, A., & Betts, W.E. 1974. A proposed rapid test for susceptibility to gaseous fluorides. Environmental Pollution (1970), 7, (4) 269-282
de Courcy Williams, M. 2002, PC 161 Protected tomatoes: integrated control of mealybugs, Horticultural Development Council, East Malling.
Defra. 2008. Average fluoride levels in zones for 2004 to 2007. Defra. Available at: . Accessed:25.03.09.
Doley, D., Hill, R.J., & Riese, R.H. 2004. Environmental fluoride in Australasia: ecological effects, regulation and management. Environmental Fluoride in Australasia, 38, (2) 35-55
Eisa, H.M. & Dobrenz, A.K. 1971. Morphological and anatomical aspects of oedema in egg plants (Solanum melongena L.). Journal of the American Society for Horticultural Science, 96, (6) 766-769
England, J. 2007. ADAS (UK) Ltd.
Farr, D.F., Aime, M.C., Rossman, A.Y., & Palm, M.E. 2006. Species of Colletotrichum on Agavaceae. Mycological Research, 110, (12) 1395-1408
Fornasiero, R.B. 2001. Phytotoxic effects of fluorides. Plant Science, 161, (5) 979-985
Gavin, G.C. 1992. Insects of the northern hemisphere Surrey, Dragon's World Ltd.
Gray, N. 2009. ADAS (UK) Ltd.
Hellyer, N. 2008. Fargro Ltd.
Henley, R. W., Osborne, L. S., & Chase, A. R. 2009. Cordyline - Ti plant. IFAS Central Florida Research and Education Center. Available at: . Accessed: 30.01.09.
Holmes, S. & Adlam, J. 2006. Factsheet 15/06: water quality for the irrigation of ornamental crops. East Malling, Horticultural Development Council.
Jones, O. 2008. ADAS (UK) Ltd (retired), plant pathologist.
Kelly, J. 1995. The Hillier gardener's guide to trees and shrubs. 1st. Newton Abbot, David & Charles.
Kinsey, G.C. 2002. Phoma nebulosa . IMI Descriptions of Fungi and Bacteria, 151, (1504)
Koppert. 2007. Koppert. Koppert Biological Systems. Koppert BV. Available at: . Accessed: 04.11.08.
Lane, C. 2009. FERA, Sandy, York.
Lang, P. & Tibbitts, T.W. 1983. Factors controlling intumescence development on tomato plants. Journal of the American Society for Horticultural Science, 108, (1) 93-98
Liefting, L.W., Padovan, A.C., Gibb, K.S., Beever, R.E., Andersen, M.T., Newcomb, R.D., Beck, D.L., & Forster, R.L.S. 1998. 'Candidatus Phytoplasma australiense' is the phytoplasma associated with Australian grapevine yellows, papaya dieback and Phormium yellow leaf diseases. European Journal of Plant Pathology, 104, (6) 619-623
Madhusmita, K., Bhagabati, K.N., Borah, P.K., & Bora, L.C. 1999. Some bacterial diseases of ornamental plants of Assam. Journal of Mycology and Plant Pathology, 29, (2) 172-175
Malumphy, C. 2009. FERA.
Marousky, F. J. & Woltz, S. S. Relationship of floral preservatives to water movement, fluoride distribuition and injury in gladiolus and other cut flowers, In Symposium on postharvest physiology of cut flowers, R. Nichols & G. Sheard, eds., International Society for Horticultural Science.
McKenzie, E.H.C., Buchanan, P.K., & Johnston, P.R. 2005. Checklist of fungi on cabbage trees (Cordyline spp.) and New Zealand flaxes (Phormium spp.) in New Zealand. New Zealand Journal of Botany, 43, (1) 119-139
Moorman, G. W. 2009. Plant disease facts. Cordyline (Ti plant) diseases. Available at: . Accessed: 20.07.09. The Pennsylvania State University.
Morley, P. & Jacobson, R. 2008, PC 240 Organic tomato: Development and implementation of a robust pesticide-free IPM programme, Horticultural Development Council, East Malling.
Morrow, R.C. & Tibbitts, T.W. 1988. Evidence for involvement of phytochrome in tumor development on plants. Plant Physiology, 88, 1110-1114
O'Neill, T. & Ann, D. 2004, Factsheet 16/04. Control of Phytophthora, Pythium and Rhizoctonia in container-grown hardy ornamentals, Horticultural Development Council, East Malling.
Papenhagen, A. 1986. High humidity has a marginal effect on plants. Gb + Gw, 86, (36) 1343-1346
Pesticides Safety Directorate. 2008. The pesticides register database. Available at: . Accessed: 29.11.08.
Pinkard, E., Gill, W., & Mohammed, C. 2006. Physiology and anatomy of lenticel-like structures on leaves of Eucalyptus nitens and Eucalyptus globulus seedlings. Tree Physiology, 26, (8) 989-999
Poole, R.T. & Conover, C.A. 1975. Influence of propagation media and amendments on fluoride toxicity of Cordyline terminalis 'Baby Doll'. Fluoride - Quarterly Reports, 8, (2) 85-92
Rangarajan, A. & Tibbitts, T.W. 1994. Exposure with far-red radiation for control of oedema injury on 'Yale' ivy geranium. HortScience, 29, (1) 38-40
Roggero, P., Ciuffo, M., Dellavalle, G., Gotta, P., & Peters, D. 1999. Additional ornamntal species as hosts of Impatiens necrotic spot tospovirus in Italy. Plant Disease, 83, (10) 967
Sagi, A. & Rylski, I. 1978. Differences in susceptibility to oedema in two tomato cultivars growing under various light intensities. Phytoparasitica, 6, (3) 151-153
San Marcos Growers. 2005. Agave edema. Available at: . Accessed 02.04.09.
Schüder, I., Port, G., & Bennison, J. 2004. The dose-dependent responses of Deroceras panormitanum and Oxyloma pfeifferi to potential novel molluscicides. Crop Protection, 23, (10) 945-953 available from:
Seabrook, J.E.A. & Douglass, L.K. 1998. Prevention of stem growth inhibition and alleviation of intumescence formation in potato plantlets in vitro by yellow filters. American Journal of Potato Research, 75, (5) 219-224
Taiz, L. & Zeiger, E. 2006. Topic 5.1: Symptoms of Deficiency In Essential Minerals. Plant Physiology Online version. 4th Ed. Available at: . Accessed: 24.07.09. Sinauer Associates.
The British Fluoridation Society. 2009. Technical and scientific aspects of water fluoridation. Available at: . Accessed: 13.07.09. The British Fluoridation Society.
Treshow, M. 1971. Fluorides as Air Pollutants Affecting Plants. Annual Review of Phytopathology, 9, (1) 21-44
Weinstein, L.H. & Davison, A.W. 2003. Native plant species suitable as bioindicators and biomonitors for airborne fluoride. Environmental Pollution, 125, 3-11
Wolting, H. 1975. Synergism of hydrogen fluoride and leaf necrosis on freesias. European Journal of Plant Pathology, 81, (1) 71-77
Woltz, S.S. 1964. Distinctive effects of root versus leaf acquired fluorides. Florida Agricultural Experiment Stations Journal Series, No. 1935, 516-517
Yu, X.H. & Bell, P.F. 1998. Nutrient deficiency symptoms and boron uptake mechanisms of rice. Journal of Plant Nutrition, 21, 2077-2088
Appendices
Appendix 1. Initial survey
|Cordyline and Phormium: pests, diseases and disorders – initial survey | |[pic] |
Section A – General information
1 Contact details.
|Your name | |
|Your nursery | |
|Address | |
| | |
| | |
|Post code | |
|Telephone | |
Section B - Cordyline
2 Please complete the following table regarding the major Cordyline varieties you grow and their provenance.
| |Variety |Country of origin |Main supplier(s) |
|1 | | | |
|2 | | | |
|3 | | | |
|4 | | | |
|5 | | | |
3 Volumes of Cordyline on your nursery
|a) On average, how many Cordyline do you grow each year? | |
|b) On average, how many Cordyline do you sell each year? | |
4 At what production stages do you produce and purchase Cordyline? (Please state quantities as appropriate)
| |Plug |Liner |1-3 L |4-5 L |> 5L |
|Purchase | | | | | |
5 Please complete the following table indicating the pests observed on your Cordyline crop and the success of any control measures used.
|Pest |Value of crop |Crop stage affected |Control measures used (chemical or |Were these measures |
| |affected (£) | |other) |successful? |
|Mealybug | | | | |
|Thrips | | | | |
|Slugs | | | | |
|Snails | | | | |
|Aphid | | | | |
|Two-spotted spider | | | | |
|mite | | | | |
|Other | | | | |
6 Please complete the following table indicating any diseases or disorders observed on your Cordyline crop and the success of any control measures used.
|Disease / disorder |Value of crop |Crop stage affected |Control measures used (chemical |Were these measures |
| |affected (£) | |or other) |successful? |
|Leaf spots (yellow) | | | | |
|Leaf spots - other | | | | |
|Tip burn | | | | |
|Stem / crown rot | | | | |
|Root rot | | | | |
|Oedema | | | | |
|Other | | | | |
Section C - Phormium
7 Please complete the following table regarding the major Phormium varieties you grow and their provenance.
| |Variety |Country of origin |Supplier |
|1 | | | |
|2 | | | |
|3 | | | |
|4 | | | |
|5 | | | |
8 Volumes of Phormium on your nursery
|a) On average, how many Phormium do you grow each year? | |
|b) On average, how many Phormium do you sell each year? | |
9 At what production stages do you produce and purchase stock of Phormium? (Please state quantities as appropriate)
| |Plug |Liner |1-3 L |4-5 L |> 5L |
|Purchase | | | | | |
10 Please complete the following table indicating the pests observed on your Phormium crop and the success of any control measures used.
|Pest |Value of crop |Crop stage affected |Control measures used |Were these measures |
| |affected (£) | |(chemical or other) |successful? |
|Mealybug | | | | |
|Thrips | | | | |
|Slugs | | | | |
|Snails | | | | |
|Aphid | | | | |
|Two-spotted spider mite| | | | |
|Other | | | | |
11 Please complete the following table indicating any diseases or disorders observed on your Phormium crop, and the success of any control measures used.
|Disease / disorder |Value of crop |Crop stage affected |Control measures used |Were these measures |
| |affected (£) | |(chemical or other) |successful? |
|Leaf spots (yellow) | | | | |
|Leaf spots - other | | | | |
|Tip burn | | | | |
|Stem / crown rot | | | | |
|Root rot | | | | |
|Oedema | | | | |
|Other | | | | |
Section D – cultural considerations
12 Please complete the following table concerning the quality of the irrigation water used on your nursery, with particular regard to your Cordyline and Phormium crops.
|Do you have your irrigation water analysed? | |
|If yes, how often? | |
|Can you provide a copy of your latest analysis if required? | |
|Do you know the level of fluoride in your irrigation water? | |
|Is fluoride added to your irrigation water by your supply | |
|authority? | |
|Which authority supplies your water? | |
13 Which type of irrigation system(s) do you use to water your Cordyline
and Phormium crops? (Please tick boxes as appropriate)
| |Overhead |Drip |Capillary matting |Efford sand-bed* |Low level (seep) |
|Phormium | | | | | |
|Any other information | |
*Drained bed sub-irrigated via header tank or similar (e.g. sand-bed irrigated by lay-flat tube).
14 What type of nutrient products do you apply to your Cordyline and Phormium crops? (Please tick boxes as appropriate)
|Base fertilisers |CRFs |Liquid feed |Supplementary |Other |
| | | |Feeds | |
15 What protection are your Cordyline and Phormium crops grown under? (Please tick boxes as appropriate)
|Glass |Polytunnel |Vented polytunnel |Other |None |
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16 Would you be interested in participating further in this project?
|Yes | |No | |
17 Do you have any preferences or other comments to make related to future Cordyline or Phormium crop research?
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Appendix 2. Case study proforma
|Cordyline and Phormium: pests, diseases and disorders – initial survey | |[pic] |
Section A – General information
Contact details
|Your name | |
|Your nursery | |
|Address | |
|Post code | |
|Telephone | |
Advance information that may be required:
Copy of irrigation and growing media analysis results
Audit details
|Auditor |Date of survey |Signature of Auditor |
| | | |
| | | |
Section B – Husbandry
1 Humidity:
1.1 Are plants spaced, and if so by how much (cm)? Please state approximate timing of spacing out and include details of any interim spacing in the box at the bottom. Specify any differences in the production of the pot sizes you produce.
| | |Plug |Liner |1-3 L |3-5 L |> 5 L |
| |Final spacing | | | | | |
|Phormium |Initial spacing | | | | | |
| |Final spacing | | | | | |
|Any other specific | |
|production techniques used| |
|(please state Cordylines /| |
|Phormiums) | |
|Other notes relating to | |
|spacing of crops | |
| | |
1.2 Air movement measures
|Are any other measures taken to ensure adequate air movement around the plant e.g. venting, fans etc? |
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2 Planting depth
2.1 How deep do you plant your crops?
| |Plug |Liner |1-3 L |3-5 L |> 5 L |
|Phormium | | | | | |
2.2 How do you handle your crops? Describe how plants are handled when moving them e.g. held by the plant, by the pot; machine or hand potted etc.
|Cordyline | |
|Phormium | |
3 Protection: are plants afforded any protection and, if so, throughout the year, over winter etc (and approx. months)?
3.1 Cordyline
| |Variety |Glass |Polytunnel (unvented) |Vented polytunnel |Other |None |
|2 | | | | | | |
|3 | | | | | | |
|4 | | | | | | |
|5 | | | | | | |
3.2 Phormium
| |Variety |Glass |Polytunnel (unvented) |Vented polytunnel |Other |None |
|2 | | | | | | |
| | | | | | | |
|3 | | | | | | |
| | | | | | | |
|4 | | | | | | |
| | | | | | | |
|5 | | | | | | |
| | | | | | | |
3.3 Overwinter protection: is frost protection applied over winter?
|What fuel is used e.g. gas or fuel oil? | |
|Is the boiler vented outside or inside the | |
|tunnel or glasshouse? | |
|Any other heating-related comments? | |
4 Irrigation
4.1 Irrigation system
| |Overhead |Drip |Capillary matting |Efford sand-bed |Low level (seep) |Other |
|Phormium | | | | | | |
| | | | | | | |
4.2 Which water sources are used to irrigate your crops?
| |Borehole |Reservoir |Mains |Roof |Bed |
| | | | |run-off |run-off |
|Other protected | | | | | |
|Outside | | | | | |
4.3 Water quality
|Are there any systems in place to clean your water, and| |
|if so what? (e.g. slow sand filters, chlorination, UV, | |
|reedbeds, settlement tanks, ozonation etc) | |
|Do you have your irrigation water analysed and if so, | |
|can you provide a copy of your latest water analysis, | |
|please? | |
4.4 Irrigation efficiency: how old is your irrigation system?
|Up to 5 yrs |6-10 years |11-15 years |Over 15 years |
| | | | |
4.5 Application regime – establishing how irrigation is applied, indicating the likelihood of over-application, well-drained, waterlogging etc.
|How do you decide when to irrigate? (timer, weather, knocking out, tensiometer to measure substrate moisture etc) |
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|Run a dry or wet regime? |
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|Any liverwort, moss, algae on the top of pots? |
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|Bed construction? |
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4.6 Irrigation efficiency:
|Give details of your irrigation system e.g. pin jet, pressure compensated. |
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|Has the performance of your irrigation system been measured, for example as described in HDC Factsheet 16/05*, and if so was |
|any corrective action required taken? |
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*HDC factsheets 16/05: measuring and improving performance of overhead irrigation for container-grown crops.
5 Growing media
5.1 Growing media formulation
| |Grade |% |
|Bark | | |
|Green compost | | |
|Grit | | |
|Coir | | |
|Peat | | |
|Woodfibre | | |
|Other e.g. wetters, polymers | | |
5.2 Growing media analysis
|Do you have your used and / or unused growing media | |
|analysed? | |
|Could you provide a copy? | |
|What pH is your growing media buffered to? | |
|Are any pesticides incorporated into your growing | |
|media e.g. for vine weevil, mealybug, and if so what?| |
|Do you retain growing media batch samples? | |
|Could you provide a sample if necessary? | |
|Do you know the AFP of your growing media? | |
|Have you carried out any particle analysis of your | |
|growing media, and if so, what were the results? | |
6 Nutrition
6.1 What nutrient products do you use?
| |Product |Formulation |Quantity |Timing of application |
|Base fertiliser | | | | |
|CRF | | | | |
|Liquid feed | | | | |
|Other | | | | |
6.2 Do you add any other products to your growing media e.g. growth stimulants?
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7 Are any biological products applied e.g. compost tea? If so please provide details.
|Product | |
|Supplier | |
|Brewing method | |
|Application regime | |
|Other relevant information | |
Section C – Pests, diseases, disorders and quality
8 Pests
8.1 Cordyline - please give details of your experiences in dealing with the pests seen e.g. the time of year when they occur, the extent of the problem, any control measures taken (chemical, cultural etc) and how successful they were.
|Mealybug |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Thrips |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Slug |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Snail |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Two-spotted spider mite |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Other |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
8.2 Phormium - please give details of your experiences in dealing with the pests seen e.g. the time of year when they occur, the extent of the problem, any control measures taken (chemical, cultural etc) and how successful they were.
|Mealybug |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Thrips |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Slug |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Snail |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Two-spotted spider mite |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Other |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
9 Diseases and disorders
9.1 Cordyline - please give details of your experiences in dealing with the diseases and disorders seen e.g. the time of year when they occur, the extent of the problem, any control measures taken (chemical, cultural etc) and how successful they were.
|Leaf spots (yellow) |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Leaf spots (Other) |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Tip burn |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Stem / crown rot |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Oedema |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Other |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Do you have a spray programme in | |
|place, and if so please give | |
|details. | |
9.2 Phormium - please give details of your experiences in dealing with the diseases and disorders seen e.g. the time of year when they occur, the extent of the problem, any control measures taken (chemical, cultural etc) and how successful they were.
|Leaf spots (yellow) |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Leaf spots (other) |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Tip burn |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Stem / crown rot |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Oedema |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Other |
|Main varieties affected | |
|Control measures | |
|Formulation | |
|Timing of application | |Rate | |
|Do you have spray programmes in place| |
|for these crops, and if so please | |
|give details. (indicate any | |
|difference for Cordyline and | |
|Phormium)? | |
9.3 Have you had any plants analysed for disease and if so, what was identified e.g. Fusarium spp. Phytophthora spp. Colletotrichum spp. etc
|Cordyline | |
|Phormium | |
10 Give details of any herbicide programme in place for these crops (indicate any difference for Cordyline and Phormium)?
|Herbicide |Formulation |Rate |Timing |
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11 Do you have any preferences or other comments to make related to future Cordyline or Phormium research?
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