Trichoderma Green Mould Disease of Cultivated Mushrooms

Abstract

AbstractThis chapter presents a literature overview about the green mould disease of cultivated mushrooms caused by Trichoderma species, a problem which may result in serious economic damage due to substantial losses of crop yield in mushroom production. The first major green mould epidemic struck the production of white button mushroom (Agaricus bisporus) in Northern Ireland in 1985, but since then, the problem has occurred in a series of further countries. Outbreaks appear to be primarily caused by two subspecies of Trichoderma aggressivum. Trichoderma green mould infection has also been observed in many countries in cultivated oyster mushroom (Pleurotus ostreatus), where the main pathogens have been described as T. pleuroticola and T. pleuroti. Moreover, various further Trichoderma species have been reported to cause green mould problems in the production of shiitake (Lentinula edodes), as well as less frequently produced other mushrooms like Ganoderma species and Cyclocybe aegerita.Components of mushroom cultivation substrata, the air, vehicles, equipment, contaminated clothing and animal vectors are among the potential sources of green mould infections. General symptoms of green mould generally appear in the mushroom cultivation substratum as large, greenish spots, but the causal agents may also colonise the surface of fruiting bodies. Green mould species compete efficiently for nutrients and space in the cultivation substratum; in addition, they produce extracellular enzymes, toxic secondary metabolites and volatile organic compounds that can lead to drastic crop losses.Species-specific primers are now available for the effective monitoring of Agaricus-, Pleurotus- and Lentinula pathogenic Trichoderma species. Control measures include pasteurisation, the use of disinfectants, chemical treatments, biological control by natural products or the use of antagonistic bacteria and fungi, as well as the breeding and cultivation of resistant mushroom cultivars.KeywordsWhite button mushroom Agaricus bisporus Shiitake Lentinula edodes Oyster mushroom Pleurotus ostreatus Ganoderma Cyclocybe aegerita Green mould disease Trichoderma