FACTORS AFFECTING BIOLOGICAL CONTROL EFFECTIVENESS OF PASTEURIA PENETRANS IN MELOIDOGYNE JAVANICA AND THE BACTERIAL DEVELOPMENT IN THE NEMATODE BODY

Abstract

The invasion and infectivity of Meloidogyne javanica juveniles (J2) encumbered with spore of Pasteuria penetrans were influenced by the temperature and the time J2 were in the soil before exposure to roots. The percentage of infected females decreased as the time juveniles spent in soil increased. When spore encumbered J2 were maintained at 30°C the decrease in infection was greater than that at 18°C. The thermal time requirements and the base temperature for P. penetrans development were estimated. The rate of development followed an exponential curve between 21 and 36°C and the base temperature for development was estimated by extrapolation to be 18.5°C. The effect of integrating a nematode resistant tomato cultivar with the biocontrol agent P. penetrans also was investigated. The ability of the biocontrol agent to reduce numbers of root-knot nematodes was dependent on the densities of the nematode and P. penetrans spores in the soil.