Knowledge on the conversion of organic wastes and green mould control in mushroom cultivation has been transferred into plant pathogen control. Research at EMR has identified the conditions needed during composting and anaerobic digestion (AD) to eradicate a range of plant pathogens which may be present in feedstock organic wastes. This is particularly important for organisms with hardy resting spores such as Plasmodiophora brassica, the causal agent of clubroot of brassicas. Laboratory bench-scale fermentations are used to simulate the conditions in large-scale composting and AD systems. This information on pathogen eradication is then tested in large-scale facilities. As new pests and pathogens are introduced into the UK, information on composting and AD technologies is being utilised in the treatment of contaminated plant wastes.
Application to soil or growing media of organic amendments such as composts has been shown to suppress several soil-borne plant diseases. This is usually due to the antagonistic effect of the compost microbiota on pathogens. Research at EMR is investigating the suppressive effect of composts on white rot and Fusarium basal rot in onion. Rather than relying on the natural background microbiota in the compost, antagonists such as Trichoderma species are introduced into the soil with the compost, which also provides a nutrient source for the antagonist. Current research is investigating the field-scale application of composts and biocontrol agents with the aim of minimising the rates of materials and inoculum required to achieve effective disease control.
For more information contact Ralph Noble