Investigating the relationship between Aphanomyces euteiches and yield decline in peas seen with increase cropping frequency whilst maintaining sufficient crop rotation.

In the UK Vining peas (frozen) are mainly grown along the east coast from Essex to Perthshire. Combining peas (dry) are more widespread. The crop provides acknowledged rotational benefits for the following crop. The annual value of the pea industry approximately £90M. However as much as 38% is lost each year to root rots and yield decline.

PGRO has been investigating the role of root rots caused by Fusarium spp. and Phoma medicaginis on pea yields for over forty years and has developed an assay to measure the likely risk and potential yield loss to these pathogens if conditions are conducive to disease development. Over time pea growers experience a gradual yield decline relating to the number of pea harvests the land has supported.

In recent years Aphanomyces euteiches has been increasingly isolated from unhealthy (and apparently healthy) pea roots in the UK. It is being diagnosed by the PGRO crop clinic with increasing frequency in root rot sometimes in association with Fusarium spp. and P. medicaginis and has been found to be part of the pea root rot complex in Canada, France and Sweden.  A. euteiches is a soil dwelling oomycete with a wide host range and peas are very susceptible. It is hypothesised that asymptomatic infection can go unnoticed in the crop with the potential to cause yield decline. The pathogen builds up in the crop until obvious symptoms are seen and dramatic crop loss occurs.

This is the least understood and studied of the pea root rot pathogens.

The project aims to study the role of A. euteiches in pea yield decline. In particular to better understand how the frequency of pea cropping influences the levels of the pathogen in the soil and to establish an index for quantitatively assessing the levels of soil borne inoculum, the resulting risk and potential yield loss to a pea crop and to indicate how the A. euteiches can best be controlled.

The project is intended to run for three years, based at PGRO.
In addition the student will have the opportunity to work within a dedicated applied science research organisation and have the opportunity to present their data at conferences. They will be expected to present to non- scientists at open days and events.

Sponsors:

University of Nottingham and Processors and Growers Research Organisation

Student:

NBrian O’Loinsigh - School of Biosciences, University of Nottingham, Leicestershire, LE12 5RD

Start Date: October 2015

Duration of study: 3 years