Effect of Rotylenchulus reniformis on yield of cowpea in pots

R. Crozzoli, G. Perichi, N. Greco


The relationship between a geometric series of ten initial densities (Pi) of Rotylenchulus reniformis, (mixtures of eggs, juveniles and immature females) from 0 to 64/cm3 soil, and growth of cowpea (Vigna unguiculata) cv. Blackeye was investigated in two-litre clay pots. Fitting the Seinhorst model, y = m + (l-m)zPiT, to average weight of seeds produced gave a tolerance limit (D to the nematode of 0.12 eggs, juveniles and immature females/cm3 soil. Minimum relative yields (m) for weight of seeds produced was 0.65 at Pi~16 nematodes/cm3• The maximum rate of nematode reproduction was 32.2-fold and occurred at the lowest initial population density. The highest final population density (PfJ of the nematode was 10.3 eggs + juveniles + immature females and eggs/ cm3 soil and occurred at Pi = 1 juvenile + young female/ cm3 soil.

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