Effect of time on the degradation of Pasteuria penetrans-infected females of Meloidogyne javanica and the proportion of parasitized nematodes in the roots of tomato planted subsequently

Different parameters were evaluated to confirm that how long Pasteuria penetrans infected Meloidogyne javanica females took to degrade and for spores to be released from the cadavers into the soil. Regression analysis was carried out to compare the degradation of P. penetrans infected females cadavers in different time intervals over two crop cycles. There were highly significant decreases in the total number of egg-masses per plant between the 3 weeks and other treatments. Infected females (%) over both crop cycles were compared by the estimated coefficients of the fitted lines and increased significantly with degradation period and significantly higher in the second crop. The 3 week duration apparently allowed more spores to disperse which was reflected in the observations of more infected female nematodes and reduced numbers of egg-masses and total females per plant compared with the first crop. The results of this experiment suggest that dispersal of spores from the degrading females occurs after 2 weeks and this is reflected in a significant reduction in egg-masses, galling and the female population between the 1 week and 3 weeks treatments. The greatest percentage of infected females and numbers of endospores were recorded in that treatment where P. penetrans infected females were left to degrade for 3 weeks.