RELATIONSHIP BETWEEN PASTEURIA PENETRANS INFECTION LEVELS AND DENSITY OF MELOIDOGYNE JAVANICA

Abstract

The interaction between three different levels of Meloidogyne javanica inoculum density and three levels of parasitism by Pasteuria penetrans was investigated in a factorial experiment. The highest and the lowest final female densities were observed at 5% initial parasitism, at the highest and lowest inoculum density, respectively. At 15% initial parasitism and increasing effect of P. penetrans on nematode multiplication was observed. No dose response effect of female density to increasing juvenile inoculum was observed at 40% initial parasitism. At this parasitism inoculum the highest female parasitism was observed at 2000 initial juveniles per pot. The final juvenile density was positively correlated with the final percentage of juveniles with spores. A. P. penetrans effect was also observed at the highest density and parasitism levels, on the number of galls and egg masses per g of root. In a second trial with two fertilization levels, plant growth higher than control and lower M. javanica density and percentage of parasitized females were observed in the treated plants. Data suggest a density dependent relationship between P. penetrans and M. javanica. However, no suppression of the nematode population at the inoculum levels used was observed.