Effect of Meloidogyne incognita and Importance of the Inoculum on the Yield of Eggplant.

The relationship between population densities of race 1 of Meloidogyne incognita and yield of eggplant was studied. Microplots were infested with finely chopped nematode-infected pepper roots to give population densities of 0, 0.062, 0.125, 0.25, 0.50, 1, 2, 4, 8, 16, 32, 64, and 128 eggs and juveniles/cm(3) soil. Both plant growth and yield were suppressed by the nematode. A tolerance limit of 0.054 eggs and juveniles/cm(3) soil and a minimum relative yield of 0.05 at four or more eggs and juveniles/cm(3) soil were derived by fitting the data with the equation y = m + (1 - m)z(PT). Maximum nematode reproduction rate was 12,300. Hatch of eggs from egg masses in water or from sodium hypochlorite dissolved egg masses was similar (41% and 39%), but egg viability was significantly greater from egg masses in water (58%) than from sodium hypochlorite dissolved egg masses (12%) after 4 weeks. Greater numbers of nematodes were collected from roots of tomatoes from soil infested with entire egg masses than from tomato roots from soil infested with egg masses dissolved by sodium hypochlorite.