Biocontrol of botrytis in strawberry and vegetable crops
The complex nature of phyllosphere ecology has, so far, militated against the development of successful biocontrol agents (BCA) for foliar plant pathogens. Consequently, biocontrol efficacy is often inconsistent and/or limited in the field; biocontrol is usually more efficacious in less variable environments. The need to predict the outcome of the interactions between a BCA and the pathogen under field conditions has repeatedly been cited as the way forward to achieve reproducible biocontrol. Unfortunately, there are only a limited number of published studies so far that deal quantitatively with BCA survival, reproduction and dispersal. To improve biocontrol there has been increasing interest recently in using mixtures of BCAs. However, both theoretical and experimental studies suggest that antagonistic interactions among BCAs are more likely to occur than synergy in combined use of BCAs. Synergy among BCAs is only likely to occur when there is large spatial variability in factors that differentially affect individual BCAs – emphasising the importance of understanding relationships of the BCA with external conditions.
Botrytis cinerea, a serious pathogen of many horticultural crops, is usually controlled by intensive fungicide applications. Using BCAs to manage Botrytis has received much attention. Currently, there are two BCA products registered in the UK: Serenade (a bacterium, Bacillus subtilis) and Prestop (a fungus, Gliocladium catenulatum). In addition, EMR has identified to two candidate BCAs (one isolate of B. subtilis and one yeast isolate of Aureobasidium pullulans) and both are effective against B. cinerea; these two strains are currently being formulated by a commercial company.
This project aims to obtain ecological knowledge on BCAs that are currently registered and being registered in the UK and then use the knowledge to develop and evaluate strategies of applying BCAs to improve efficacy against Botrytis development on strawberry and lettuce.