Biological Control of Tomato Grey Mould with Compost Water Extracts, Trichoderma sp., and Gliocladium sp.

Abstract

Compost water extracts prepared from animal sources (horse, sheep, and cattle) and a plant source (olive) were tested for their control of leaf grey mould on tomato. Disease was reduced by 27–66% and by 41–70% by extracts after 7 days and 15 days of fermentation respectively. No effect was noted with extracts after only 10 hours of fermentation. Conidial suspensions of Trichoderma harzianum, of Gliocladium sp. and compost extracts derived from horses achieved similar and significant (P<0.05) reductions in grey mould as compared to the water control. Dilution of extracts did not impair extract effectiveness if they were derived from horse and ovine compost. Pasteurization of extracts significantly reduced their effectiveness, particularly in the case of olive, but compost extracts from other sources achieved significant grey mould reduction despite pasteurization.