EVALUATION OF SESAME FOR CONTROL OF MELOIDOGYNE-ARENARIA AND SCLEROTIUM-ROLFSII IN PEANUT

Sesame (Sesamum indicum) was evaluated in a 6-year field experiment as a rotation crop for the management of root-knot nematode (Meloidogyne arenaria) and southern blight (Sclerotium rolfsii) in 'Florunner' pea nut (Arachis hypogaea). The experiment was initiated in 1988 in an irr igated field with severe M. arenaria and S. rolfsii infestation which had been in peanut production with winter fallow for 10 years. Rotatio ns with bahiagrass (Paspalum notatum) were included as positive contro ls, Meloidogyne arenaria juvenile (J2) population densities in soil we re reduced in plots with sesame or bahiagrass, while aldicarb applied to monoculture peanut failed to reduce J2 population densities in all but 1 year. Incidence of southern blight was lowest in peanut followin g 2 years of bahiagrass, while disease incidence in peanut following 1 year of bahiagrass was no less than that in peanut monoculture. Cropp ing systems with sesame had no consistent effect on southern blight. Y ield of peanut without nematicide following 1 year of sesame uas highe r than yield from continuous peanut without nematicide in 2 out of 3 y ears. Yield of peanut following 2 years of sesame was higher than mono culture peanut with and without nematicide. The relationship between M . arenaria juvenile populations and peanut yield was not influenced by cropping system and was significant for all years except 1990. Peanut yield was inversely and linearly related to the number of southern bl ight disease loci, and the relationship between these 2 variables was unaffected by cropping systems but Ras influenced by production year.