Management of dry root rot of greengram (Vigna radiata) caused by Macrophomina phaseolina

Abstract

The experiment of screening was conducted during 2006 and 2007 to evaluate 25 greengram [Vigna radiata (L.) Wilczek] genotypes for resistance to root rot caused by Macrophomina phaseolina (Tassi.) Goid. Complete resistance to root rot could not be found, however, ‘MSJ 118’ genotype exhibited highest suppression of dry root rot, followed by the genotype ‘KM 4-59’ and appeared as moderately resistant genotypes. In compost experiment 4 different composts, viz banana (Musa accuminata), nadep, Calotropis and vermicompost have been used as soil amendments to determine their influence on disease incidence and soil microflora during rainy (kharif) 2007 and summer season 2007 and 2008 in greengram plants in pots (cv. ‘RMG 492’). The composts in general enhanced microbial populations in amended soil resulting in reduction in the disease incidence. Banana and vermicompost amended treatments were found superior in the suppression of dry root rot, while C. procera compost-amended treatment showed the least suppression of the disease. Among composts, the counts of fungi, bacteria and actinomycetes were again higher in the vermicompost and also in the soil, amended with vermicompost, followed by banana compost amended soil, while Calotropis and Calotropis compost-amended soil had least counts of microflora.