Biology and management of false truffle (Diehliomyces microsporus) during cultivation of Agaricus spp.

Abstract

Pure culture of Diehliomyces microsporus was raised from mature ascocarps when they started turning brown on Malt Extract Medium. In vitro germination of ascosproes was successful and it was possible only after breaking the dormancy of ascospores by hot water treatment at 45C for 24-28 hours. A temperature of 26-30C was found optimum for the germination of ascospores Thermal death point for the mycelium ad ascospores of D.microsporus was found to be 45C for 30 minutes and 70C for 1 hour, respectively. The viability period of mycelium was 6 months while ascospores o=could remain viable up to 5 years. Inoculation with false truffle at spawning stage resulted in 95 and 46 per cent yield loss in Agaricus bisporus and A. bitorquis respectively. A. bisporus strains were found more sensitive to competition as compared to A.bitorquis strains. Dissipation rate of effective fungicides (based on in vitro evaluation) was worked out in compost and casing soil under mushroom growing conditions and on the basis of this a spray schedule consisting of three sprays was developed which was found to give excellent control of false truffle. Among plant material,s, water hyacinth proved quite effective in controlling false truffle. Considerable variation in microflora associated with diseased (false truffle) and healthy crop was noticed.