Soil bioassay with time interval and spore density factors affecting the infection of Meloidogyne javanica by Pasteuria penetrans

A bioassay study was conducted to confirm the effect of different time intervals on the degradation of M. javanica females cadavers filled with of P. penetrans endospores, release and dispersal in the soil. Three time intervals, of one week, two weeks and three weeks were allowed to observe the degradation of infected female cadavers and the dispersal of released endospores. The hypothesis of this experiment was that, the spores of P. penetrans contained in M. javanica females that have been placed in soil would be released as the cadavers decompose and would attach to fresh J2s added to the soil. A very highly significant difference was observed between the treatments as compared to control treatments of both crop cycles. The bioassay revealed a significant decrease in the total number of second stage juveniles from 50 g of the soil samples from second crop than the first crop soil samples. Three weeks duration allowed more endospores as compared to one week and two weeks treatment. These results showed that dispersal of endospores form the degrading female cadavers occurred after two weeks.