Previous Projects
Previous projects undertaken by Plant Health Solutions or its director, Dr Steve Roberts.
Management of Bacterial Canker in Prunus spp.
2010 - 2013Bacterial canker has been an on-going problem for HNS growers for many years and also causes losses to stone fruit growers. Bacterial canker may be caused by two distinct pathovars of Pseudomonas syringae: pv. morsprunorum (Psm)and pv. syringae (Pss). Psm is host specific to Prunus spp., whereas pv. syringae has a much wider host range, with the potential for cross infection between a number of different species and genera. Although the stem canker phase is the most economically important, these pathogens may also cause leaf spots/shot-holes, shoot die-back and flower blights. The overall aim of the project will be to identify management options which will be of benefit in the control of bacterial canker of Prunus spp. To achieve this the project will: aim to identify the main sources of primary inoculum on propagation nurseries; examine the potential of targeted treatments to reduce/eliminate inoculum; examine the relative merit of different practical approaches for cleaning/disinfection of pruning knives/secateurs; and critically review relevant scientific and advisory literature and draw together with the new experimental work to produce a factsheet with clear practical recommendations.
Funded by: AHDB - Horticulture
Bacterial diseases of herbaceous perennials
2010 - 2013Bacterial diseases have caused sporadic but significant (e.g. 100% crop loss) problems in a number of HNS herbaceous subjects for a number of years. There is a general lack of knowledge amongst growers about how to identify diseases caused by bacteria; and except for well known diseases with clear symptoms, the only reliable way of diagnosis is by laboratory examination and culturing, thus accurate information is difficult to obtain.
During the first year nurseries will be surveyed for bacterial diseases. The results will be used to inform and direct the work in subsequent years which will comprise trials work and detailed epidemiological investigations in years 2 and 3. The project aims to benefit herbaceous HNS growers by providing information which will assist in the identification of bacterial diseases and identify practical management strategies for their effective control. This is expected to lead to a reduction in the use of ineffective spray treatments, and reduction in losses and ultimately increased profitability.
Funded by: AHDB - Horticulture
Relationship between disease incidence in stored bulb onions and first year sets
2011 - 2012There is a perception that the risk of certain onion diseases may be increased when crops are grown from sets. The major diseases of concern to the industry are: bacterial rots thought to be caused mainly by Burkholderia gladioli pv. alliicola (Bga; particularly in heat-treated red Rijnsburger type onions), neck rot caused primarily by Botrytis aclada/allii and Fusarium basal rot caused by Fusarium oxysporum fsp. cepae. One possibility is that the necessary heat treatment of some cultivars may lead to increased risk of disease. This project represents a first step to address these issues by determining the incidence of the major bacterial and fungal onion pathogens thought to be associated with sets of different types and establish if there is a relationship between disease incidence in sets and subsequent problems in the harvested bulb onion crop. It is anticipated that, based on these initial results, a follow-on project will investigate way of reducing the impact of any disease problems associated with sets.
Funded by: AHDB - Horticulture
Disease management in organic brassica seed and transplants
2009 - 2011The project aims to evaluate a range of organically acceptable brassica seed and transplant treatments for their efficacy and cost effectiveness in controlling a range of common soil, seed and air-borne diseases. The treatments tested will include microbial inoculants and suppressive composts that are currently available for use in the EU. The work will benefit both organic and conventional plant raisers and growers by exploring alternative options for disease management that reduce disease levels and improve the quality of brassica transplants. The project will be a collaboration between Warwick HRI, Plant Health Solutions and Garden Organic (HDRA).
Funded by: AHDB - Horticulture
Outdoor herbs: Integrated management of parsley septoria and coriander bacterial blight
2007 - 2010This project, a collaboration between Plant Health Solutions and ADAS, aims to improve understanding of the relationships between seed infection levels and disease development in two seedborne diseases of herbs: leaf spot on parsley (Septoria petroselini) and bacterial leaf blight on coriander (Pseudomonas syringae pv. coriandricola). Options for seed treatment and disease controls in the field will also be examined to provide integrated strategies for disease management.
Funded by: HDC
Evaluation of disinfectants, biological and natural products for control of brassica black rot
2008 - 2009Black rot, caused by the bacterium Xanthomonas campestris pv. campestris (Xcc) continues to cause sporadic problems in brassica production. The disease is seedborne, so control is mainly through the use of 'clean' seed. Building on the results of an earlier EC-funded project (STOVE) which identified biological control agents and a natural product with activity against Xcc, and using methods developed in previous Defra-funded projects, these BCA?s and the natural product will be investigated for their potential as either seed and/or foliar treatments for the management of black rot in vegetable brassicas. Additional disinfectant compounds identified in a previous HDC project (FV 314) will also be evaluated.
Funded by: HDC
A review of the literature on bacterial diseases of lettuce
2007 - 2008Bacterial breakdown has been causing severe problems in outdoor crisphead lettuce for the last couple of years. As a first step in tackling the problem HDC is funding Plant Health Solutions to review the existing literature prior to committing funds to any experimental work.
Funded by: HDC
Onion downy mildew and leaf wax continuation
2006 - 2007This project , in collaboration with VCS, is examing the role of cuticular leaf wax in the natural resistance of onions to downy mildew caused by the oomycete pathogen Peronospora destructor. HDC Project No. FV277a
Funded by: HDC
To understand the interactions of leaf wax and downy mildew in onions
2005 - 2006Funded by: HDC
Seed treatments for organic vegetable production
2004 - 2006Funded by: EC
Promotion of quality vegetable seed in Kenya
2003 - 2005This project aims to promote a sustainable system for farmer-led multiplication of kale seed for peri-urban smallholder farmers in Kenya, in order to improve the quality, health and availability of kale seed. Also, the concept and value of producing or purchasing good quality seed will be promoted.
Funded by: DfID
Evaluation of novel sterilants and active ingredients for the control of fungal and bacterial diseases in bulb onions
2004 - 2005In this project, led by VCS, the efficacy of sterilants and novel products for the control of both fungal and bacterial onion foliage and bulb diseases will be examined in field trials at two sites. HDC Project No. FV 264.
Funded by: HDC
Evaluation of seed treatments
2004 - 2005Funded by: Germains
New techniques for genetic improvement of horticultural brassicas
1999 - 2004A large collaborative project
Funded by: DEFRA
Bacterial pathogen epidemiology using lux/gfp markers
2001 - 2004Bioluminescent marker genes (lux) were introduced into strains of Xanthomonas campestris pv. campestris. The marked strains spontaneously emit light when metabolically active which allows them to be tracked in real time using a sensitive CCD camera system. Spread of the lux-marked strains was then followed non-destructively in brassica plants from inoculated seeds to mature flowering plants and pods.
Funded by: DEFRA
Effect of the composting process on particular plant, animal and human pathogens known to be of concern for high quality
2002 - 2004This project, in collaboration with Prof. Ralph Noble at HRI, examined the risks of transmission of plant and human pathogens in composted green waste, by reviewing the existing scientific literature and experiments with selected pathogens.
Funded by: WRAP
HNS 91 Bacterial diseases of HNS: chemical control
2000 - 2002Funded by: HDC
Black rot of Brassicas: Epidemiology
1998 - 2002Examined spread of Xanthomonas campestris pv campestris in module-raised brassica transplants and in transplanted field crops
Funded by: MAFF
Improving the quality of salad products
1998 - 2002In collaboration with commercial partners and IFR, this project examined factors influencing discoloration of pre-packed cut lettuce.
Funded by: HortLink (Defra)
Bacterial Canker of Cherry (Prunus avium): biology, epidemiology, resistance
1999 - 2002This project was concerned with the only two practical approaches to controlling bacterial canker in farm woodland cherries: disease avoidance and disease resistance. ?Both of these approaches had been limited by a lack of understanding of the pathogen and a lack of reliable and consistent methods. The project aimed to improve understanding of the pathogen, its taxonomy and variation and develop improved methods for detection and discrimination. This was a necessary prerequisite for studies on the epidemiology of this disease in farm woodland cherries to identify the most important sources of infection and for the development and application of improved methods for disease resistance screening.
Funded by: DEFRA
Organic Seed Production
1999 - 2002This project examined the feasibility and problems associated with production of seed of a range of vegetable crops according to organic standards
Funded by: DEFRA
Disinfectants for salad washing
2001 - 2002Commercial
Funded by: Degussa
HNS 92? Hedera: Biology and Epidemiology of Xanthomonas leaf spot
1998 - 2001Funded by: HDC
Spear rot of Calabrese
1998 - 2001Previous work had shown that the primary causal agent was a Group IV Pseudomonas, an organism with pectolytic (soft-rot) enzymes and biosurfactant properties. This project aimed to: (1) make a molecular characterisation of Group IV Pseudomonas and develop a specific and sensitive detection procedure based on a selective/diagnostic medium linked to serological and/or molecular identification systems; (2) test the hypothesis that Group IV Pseudomonas, the causal agent of spear rot, is seed transmitted and that the pathogen has an epiphytic stage before disease expression; (3) develop a control strategy based on disease avoidance through the use of clean seed, monitored by a specific and sensitive detection procedure; (4) make observations on the possible relationship between spear rot and brown bud symptoms in cv Marathon
Funded by: MAFF
Extraction methods for Xanthomonas
2000 - 2001Comparison of methods for extraction of Xanthomonas from brassica seeds
Funded by: ISHI-Veg
FV 186a Brassicas: use of copper spray to control Black Rot during transplant production
1999 - 2000Glasshouse trials with weekly applications of copper oxychloride
Funded by: HDC
Reference Materials for seed health testing
1996 - 1999In collaboration with researchers at Wageningen, this project developed standardised reference materials for use in seed health testing. Standardised reference materials are stabilised microbial preparations containing a known number of organisms. Such materials are vital for successful and efficient seed test method validation and proficiency testing and can perform an important role in any test QA system.
Funded by: EC
Aetiology and control of bacterial leaf spot of cherry laurel
1995 - 1998Funded by: MAFF
Vegetable diseases of unknown aetiology
1995 - 1998Funded by: MAFF
Brassicas: Development of a Screening System to detect Xanthomonas campestris in seed and evaluation of pathogen resista
1995 - 1998Funded by: HDC
Enhanced degradation of pesticides
1994 - 1997Funded by: MAFF
Hardy Nursery Stock: Bacterial Diseases (HNS 71)
1996 - 1996Commercial nurseries were surveyed for the presence of suspected bacterial diseases. Disease samples were collected and isolations attempted to confirm the presence of the suspected pathogens.
Funded by: HDC
Seedborne diseases of peas
1992 - 1995Funded by: EC
Bacterial blight of peas
1990 - 1994Funded by: MAFF
Enhanced degradation of pesticides
1990 - 1994Funded by: MAFF
Bacterial blight of peas
1987 - 1990Funded by: MAFF