Novel approaches for the management of leaf and bud nematodes (Aphelenchoides spp) in hardy nursery stock

SRUC, Scotland’s Rural College, delivers comprehensive skills, education and business support for Scotland’s land-based industry founded on world class, sector leading research, education and consultancy. Our 1500 staff are located on 6 campuses and around 40 business units across Scotland and the North of England.

This studentship is funded by the HDC (Horticulture Development Company), a subsidiary of the Agriculture and Horticulture Development Board (AHDB). The aim of this PhD is to develop new guidelines for the integrated management of foliar nematodes in hardy nursery stock utilising existing and novel methods. Leaf and bud nematodes (primarily Aphelenchoides ritzemabosi and A. fragariae) are widespread and damaging pathogens of ornamental plants grown in greenhouses and nurseries. This PhD research project aims to address the relative lack of treatments available to growers for the management of foliar nematodes in hardy nursery stock by evaluating the potential and efficacy of treatments that can be applied to the soil for contact and systemic control of nematodes, and as foliar treatments for systemic nematode control, and as elicitors of resistance within the plant against nematodes. The mechanism underlying induction of nematode resistance by elicitors will be determined and assessed in a range of hardy nursery stock plants via the development of a simple assay to identify species/varieties that are responsive to elicitors.

The approach to be undertaken will target three distinct phases of nematode infection: movement from soil to the plant; movement within the plant; and induction of plant resistance to infection and nematode multiplication within the plant. Laboratory and glasshouse pot tests will evaluate the efficacy and persistence of a range of soil applied treatments for their contact toxicity to leaf and bud nematodes. Application of products and compounds that act as elicitors of systemic acquired resistance will be evaluated to determine whether they can induce natural defences and confer levels of resistance to nematodes, and how long this level of resistance lasts. Treatments that have shown promise from the glasshouse pot tests will be investigated further in similar pot tests with differing combinations of treatments and timings to refine and develop treatment programmes that will be evaluated in glasshouse trials and at commercial nurseries. The PhD student will be encouraged to attend grower meetings to outline the research to be undertaken and to engage growers with the research process, particularly as grower involvement to carry out field trials is an essential component of this project.