Efficacy of weed residues vis-a-vis their composts on survival of Macrophomina phaseolina and dry root rot incidence on clusterbean.

摘要

The effects of partially decomposed residues and composts of Aerva persica, Celosia argentea and Euphorbia hirta on the survival of M. phaseolina and on the incidence of dry root rot in cluster bean were studied in Jodhpur, Rajasthan, India, during 1998-2000. The weed residues and composts were incorporated separately or in combination at 0.5 t/ha to a depth of 20 cm. Soil amendment with weed residues or composts markedly reduced plant mortality due to dry root rot. Among the residues, those of A. persica were superior in the reduction of plant mortality except in 1999, when this treatment was as effective as C. argentea. The combination of these residues was more effective than the individual treatments in 1999 only. Under laboratory conditions, the initial population of M. phaseolina was markedly reduced by all treatments in 2000. The combination of composts was also the most effective. Among the residues, E. hirta residue resulted in the lowest viable counts of M. phaseolina, whereas among the composts, C. argentea and E. hirta were superior.