Peanut-cotton-rye rotations and soil chemical treatment for managing nematodes and thrips

In the southeastern United States, a cotton-peanut rotation is attractive b ecause of the high value and extensive planting of both crops in the region . The objective of this experiment was to determine the effects of cotton-p eanut rotations, rye, and soil chemical treatments on management of plant-p arasitic nematodes, thrips, and soilborne fungal diseases and on crop yield . Peanut-cotton-rye rotations were conducted from 1988 to 1994 on Tifton lo amy sand (Plinthic Kandiudult) infested primarily with Meloidogyne incognit a race 3, Belonolaimus longicaudatus, Sclerotium rolfsii, Rhizoctonia solan i, and Fusarium oxysporum. Continuous peanut, continuous cotton, cotton-pea nut rotation, or peanut-cotton rotation were used as main plots; winter rye or fallow as sub-plots; and cotton with and without aldicarb (3.36 kg a.i. /ha), or peanut with and without aldicarb (3.36 kg a.i./ha) plus flutolanil (1.12 kg a.i./ha), as sub-sub-plots. Population densities of M. incognita and B. longicaudatus declined rapidly after the first crop in continuous pe anut and remained low thereafter. Neither rye nor soil chemical treat ment affected M. incognita or B. longicaudatus population density on peanut or c otton. Cotton and peanut yields from the cotton-peanut rotation were 26% an d 10% greater, respectively, than those from monoculture over the 7-year st udy. Cotton and peanut yields were improved 9% and 4%, respectively, follow ing rye vs. fallow. Soil chemical treatments increased yields of cotton 23% and peanut 32% over those of untreated plots. Our data demonstrate the sus tainable benefits of using cotton-peanut rotations, winter rye, and soil ch emical treatments to manage plant-parasitic nematodes and other pests and p athogens and improve yield of both cotton and peanut.