Adaptability and Persistence of Pasteuria penetrans in different Cropping Sequences

In root-knot nematode infested microplot, the bacterial parasite, Pasteuria penetrans was added @ 1g root powder/m² containing approximately 2 x 10⁷ spores. Four sequences of crops viz. okra-cowpea-tomato-brinjal; jute-chilli-cabbage-french bean; cowpea-maize-tomato-okra and cucumber-maize-onion-brinjal, were grown in the microplots one after another in the respective sequences. The build up of bacterial population in the root-knot infected roots was estimated after the harvest of each crop. P. penetrans population multiplied and persisted well throughout the year in the cropping sequences. Maximum bacterial spore population/unit weight of root powder was recorded in okra-cowpea-tomato-brinjal followed by jute-chilli-cabbage-french bean.