Advances in Experimental Agriculture Vol-III
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different seasons. In this chapter we only discussed about management aspect of this fungus since other aspects like ultrastructure and morphogenesis of sclerotia, soil biology, pathogenesis and disease development have been reviewed by Aycock, 1966, Punja, 1985, Sarma et al., 2002 and Arunasri et al., 2011 . The management of this fungus classified into i. Cultural management, ii. Biological management, iii. Chemical management, iv. Integrated management.
Cultural management Fertilizer and manure In case of fertilizer, mechanism of nitrogen N action, both in form and level, was studied in vitro and it was shown that lower levels of NO3- or NH4 50 ppm were inhibitory, while higher levels were directly toxic to sclerotial germination. Effect of NO3- were not dependent on soil pH. A wide variety of nitrogenous substances including inorganics like NH 3 , NH4 NO3-, Ca NO3 2 and organics like chitin, peptone and ammonium acetate affect germination. Such inhibition of germination was attributed to a build up of antibiotic producing bacteria in the mycosphere, b release of NH3 that temporarily raised soil pH to above 8.5 and caused direct toxicity and c
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direct toxicity of the ions Sen, 1983 . Use of farm yard manure reduces root rot of Cyamopsis psoraloides and chick pea. While Sahni et al., 2008 found significant protection of chick pea from S. rolfsii after use of vermicompost. Aqueous extract in vitro and some crop residue in soil appeared to inhibit the growth of the pathogen in soil. Alfalfa hay distillate containing volatiles like methanol, acetaldehyde, isobutyraldehyde and isovalerldehyde stimulated germinationlysis in the absence of the host. Decomposition of some crop residue like alfalfa hay, legume residue and oilcakes like those of groundnut and Sesamum indicum released NH3 that was directly toxic to sclertia.
Use of micro-elements and macro-elements Management of diseases caused by S. rolfsii through application of micro element calcium and macro element, nitrogen in different forms has been described by many workers Punja, 1989 . The earliest observations on the influence of nitrogenous fertilizers on development of S. rolfsii were made by Leach and Davey 1942 who showed that heavy post-plant applications of anhydrous ammonia and ammonium sulphate reduced disease on sugar beet from 30 to 7.6 and 9.2 , respectively. Similarly, Punja and Grogan 1982 have shown that extremely low doses of ammonium nitrogen compounds provided a high level of control on the disease in golf greens.