Location and transmission of Macrophomina phaseolina and Alternaria alternata in okra.
A total of 115 okra seed samples collected from different sources were subjected to Standard Blotter Method (SBM) for isolation. Five samples showing higher infestation of seed borne fungi in SBM were selected for studying the location and transmission of the pathogen. Macrophomina phaseolina recorded 2-5% in seed coat, 0-5% in fringe layer, 0-4% in cotyledons, 0-4% in endosperm and 0-3% in embryonic axis. Alternaria alternata was 0-4% in seed coat, 0-3% in fringe layer, 0-2% in the cotyledons, 0-2% in endosperm and 0-2% in embryonic axis in Kharif (monsoon). In Rabi (post-monsoon), M. phaseolina was 0-4% in seed coat, 0-5% in fringe layer, 0-10% in cotyledons, 0-2% in endosperm and 0-1% in embryonic axis while A. alternata 2-3% in the seed coat, 0-3% in fringe layer, 1-3% in cotyledons, 0-2% in endosperm and 0-1% in embryonic axis. The seeds harvested during Kharif and Rabi season favoured the more number of pathogens in the seed coat than in the other components. The transmission of M. phaseolina and A. alternata was 12.2% in Kharif. In Rabi, the transmission was 18.2% in all the five seed samples. The present study revealed that the disease transmission was more during Rabi than Kharif season.