Vining peas: development of a laboratory based assay for the detection of Common Root Rot (Aphanomyces euteiches)

Project summary:

Vining peas are susceptible to fungal root rots. Infected plants either mature prematurely or die before harvest. Once the infection is in a field, crop losses can be large and ideally peas are not grown for ten years to enable the fungal population to decline to safer levels. Currently there are three fungal pathogens which cause root rots; Fusarium solani, Phoma medicaginis and Aphanomyces euteiches. F. solani and P. medicaginis can be detected in the field in the UK but A. euteiches cannot. This project will evaluate the methods used in research projects to isolate A. euteiches from soil.

Benefits to the industry:

Growers are increasingly concerned about the problems of root rots when growing vining peas especially in land that has had peas in the rotation for a number of years. In the UK there are three main fungi which cause these rots; F. solani, P. medicaginis and A. euteiches. There is a soil test available for the first two. This identifies the disease loading of the soil and provides a risk rating which can be used to influence crops grown and drilling times. However there is not a test for A. euteiches and very little is known about its distribution in the UK. This project will investigate techniques that could be used to develop a test for A. euteiches. The aim is to evaluate known methods and develop a time efficient technique for testing soils for risk of crop loss due to A. euteiches. Following this project numerous fields could be tested for disease and yield correlations. The progress made will be presented to the growers at grower events and in articles. In addition the results will be presented as a poster at specialist pathology conference.

Aims and objectives:

Project aim(s):

To evaluate glasshouse and microbiological methods as possible techniques for detecting Aphanomyces euteiches in vining peas.

Project objective(s):

a) Literature review to identify techniques to identify the pathogen in vining pea soils using microbiological and glasshouse assays;

b) Identify technique(s) most suitable for a ‘non-glasshouse assay’ for the identification of A. euteiches;
c) Compare the techniques identified in b) with the pot test already in use. Modify these techniques to improve the efficiency of the assay;
d) Identify A. euteiches presence/absence in three field samples from geographically different areas;
e) Compare plant symptoms and yield to the results of d);
f) Present the findings to growers at Road shows and technical meetings.