NEMATODES AND FUNGI ASSOCIATED WITH POD ROT OF PEANUTS IN OKLAHOMA

Abstract

Peanut fields in four Oklahoma counties were surveyed for pod rot and associated plant parasitic nematodes from early September to mid October during 1983-1985. Mean annual pod rot incidence over 3 years was 5.8 - 21.3%. Meloidogyne hapla was the most commonly found plant-parasitic nematode, followed by Pratylenchus brachyurus, and species of Tylenchorhynchus and Criconemella. Pod rot incidence (15.1%) was greater (P=0.05) in fields infested with these nematodes than in fields without them (7.1%). Meloidogyne hapla was consistently associated with presence of pod rot in fields, and with fungi isolated from pods. Pythium myriotylum, Rhizoctonia solani (anastomosis group 4) Sclerotium rolfsii and Fusarium spp. were the principal fungi isolated from pods with symptoms. Survey results suggest that plant parasitic nematodes, particularly M. hapla, play an important role in peanut pod rot etiology in Oklahoma.