Abstract
In a greenhouse experiment, a population consisting of 1,500 Pratylenchus zeae in 20-cm pots were pathogenic on sorghum, and suppressed top and root growth. Pronounced necrosis of the roots resulted. Top growth was retarded by combinations of P. zeae-Curvularia spp., P. zeae-Fusarium moniliforme, P. zeae-Rhizoctonia solani, and P. zeae-Macrophomina sp., and by F. moniliforme and R. solani, alone. All nematode-fungi combinations and all fungi alone suppressed root growth. The combination P. zeae-Curvularia spp. produced most damage. P. zeae-R. solani, Curvularia spp., and F. moniliforme produced severe necrosis of sorghum roots. An initial inoculum of 750 P. zeae in 20-cm pots was not pathogenic on sorghum in a second experiment. Only the combination of P. zeae-F. moniliforme affected the fresh root weights; dry root weights were retarded significantly by P. zeae-F. moniliforme and by F. moniliforme, alone. The intensity of necrosis also varied with the different inocula.