Interaction of Meloidogyne arenaria with tobacco grown at different stress levels, imposed by plant spacing and ridge height, was studied. Early in the season population densities of eggs and larvae were greatest at close spacing and in low ridges. Later, as interplant competition increased, nematode densities were greatest on the most vigorous plants, those at the widest spacing on high ridges. Averaged across ridge heights, tobacco yield per unit area was greatest at 51 cm spacing, least at 76 cm and intermediate at 25 cm. Yield per plant was lowest at the close spacing and greatest at the wide spacing. Yields were slightly greater with high ridges than with low ridges. Sampling error in nematode density determinations caused marked inflation of the variance estimates.

(Full article published with kind permission from "Tobacco International")