Control of Pathogens and PestsA number of harmful fungi and bacteria are encountered in composts which deplete the nutrients present for growth of mycelia, and attack fruit bodies at different growth stages of crops, resulting in serious crop losses. Myco-viruses are also known to attack mushrooms. Biological control of nematodes through plant extracts and nematophagous fungi are being tried at Solan. Leaf extract of castor, madar (Calotropis) were lethal to nematode (e.g. Aphelenchoides composticola) followed by neem, chrysanthemum, bhang (Canabis sativa), safeda and marigold, respectively. Incorporation of dried plant materials of above plants to compost increased yield to 7-12 per cent through favorable shift in the compost mycoflora (Sohi, 1988).