Studies on sorghum [Sorghum bicolor(L.) Moench.] grain Molds and their management

Abstract

Sorghum [Sorghum bicolor (L.) Moench] is a vital life-sustaining food crop for humanbeing as well as for livestock in many parts of world. It is one of the major staple foods for the world’s poorest and insecured people. Many improved varieties have developed in several countries in recent years, many of them were found to be susceptible to diseases due to narrow genetic makeup. Therefore, were discarded by the farmers within a short period of use. Among, the several sorghum fungal diseases occurring in Maharashtra, viz., Anthracnose (foliar, head, root and stalk rot), Charcoal rot, Downy mildew, Damping-off, Grain discoloration, Leaf spot, Leaf blight, Root rot, Seedling blight and Smut are appearing every year. Among the several sorghum diseases, majority of them are reported to be seed borne. Therefore, considering the importance of the problem, the present investigations were carried out on various aspects to generate more information on seed borne fungi of sorghum. The natural symptoms and signs of discolored sorghum grains were studied by collecting different discolored earheads from various parts of Maharashtra. The isolation, microscopic examination and identification of detected fungi were carried. Nine fungi viz., Fusarium moniliforme, Fusarium oxysporum, Colletotrichum graminicola, Macrophomina phaseolina, Curvularia lunata, Alternaria alternata, Phoma sorghina, Aspergillus niger and Aspergillus flavus belonging to seven genera were found associated with discolored disease sorghum grains. The pathogenicity test of predominant fungi, viz., F. moniliforme, C. graminicola, A. alternata, F. oxysporum and M. phaseolina were found positive. These pathogens adversely affect seed germination and cause seedling mortality in in vitro and in vivo. In case of F. moniliforme seed germination and seedling mortality in vitro and in vivo was 58.0, 75.00 and 62.0, 78.00 per cent, respectively, which was found to be most pathogenic. The reisolation from diseased seeds and blighted seedlings yielded the same respective pathogen, used for inoculation.