Interaction of Pratylenchus zeae with Four Soil Fungi on Sorghum

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.

Evaluación agronómica de diez híbridos de sorgo en la costa sur de Puerto Rico en 1993 y 1994

“…Sorghum research on various management and control aspects has been done in Puerto Rico for over 30 years. Research areas covered have included fertilization Lugo-López, 1978), weed control (Almodóvar-Vega, 1984;Miller et ah, 1969), bird resistance (Sotomayor-Rios, 1977), plant pathogen resistance (Bee-Rodriguez and Ayala, 1977;Feliciano et al, 1986;Hepperly, 1988), soil stress (Abruña et al, 1983;Wahab et al, 1976), sweet sorghum potential (Aisina et al, 1975), and forage quality and performance (Caro-Costas, 1981;Méndez-Cruz et al, 1990;Sotomayor-Rios and Santiago, 1981). Few experiments, however, have dealt with commercial sorghum hybrid yield potential in Puerto Rico.…”