Effects of Meloidogyne incognita and Rotylenchulus reniformis on Growth and Nutrient Content of Vigna unguiculata and Zea mays

Abstract

In a greenhouse experiment, seedlings of cowpea (Vigna unguiculata cv. Yvon Clay) and corn (Zea mays cv. X306B) were grown for 6 weeks in pots receiving initial inoculum (Pi) of 0, 100, 1 000, or 10 000 eggs of Meloidogyne incognita race 1 or immature, vermiform Rotylenchulus reniformis race A. Final nematode populations, plant growth, and concentrations of 11 plant nutrients within shoots and roots were measured. Each nematode reproduced on both hosts but final populations were larger on cowpea than on corn. Both nematodes stunted the growth of each host. Leaves of corn plants inoculated with 1 000 M. incognita eggs or with 10 000 vermiform R. reniformis showed symptoms of nutrient deficiency. For each host-parasite combination, there were more differences in nutrient concentrations in roots than in shoots, when infected and noninfected plants were compared. Specific effects of nematode parasitism on host nutrient concentrations differed with the host and the parasite. However, when