ROTATIONS WITH COASTAL BERMUDAGRASS, COTTON, AND BAHIAGRASS FOR MANAGEMENT OF MELOIDOGYNE-ARENARIA AND SOUTHERN BLIGHT IN PEANUT

The efficacy of coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne arenaria) in 'Flor unner' peanut (Arachis hypogaea) was evaluated in a 3-year field trial . Coastal bermudagrass-peanut rotation (CBP) was compared with peanut monoculture without nematicide (P-) and peanut monoculture with aldica rb (P+). The performance of CBP was also compared with 'Pensacola' bah iagrass (Paspalum notatum)-peanut (BP), and 'Deltapine 90' cotton (Gos sypium hirsutum)-peanut (CP) rotations. Each rotation crop was grown f or 2 years (1998, 1992) and peanut was planted without nematicide the third year (1993). In contrast with peanut, the alternate crops of bah iagrass, bermudagrass, and cotton did not support M. arenaria populati ons. In 1993, the lowest numbers of M. arenaria second-stage juveniles (J2) in soil were in plots with CP and BP; these rotations resulted i n the highest peanut yields. CBP failed to increase peanut yield and r esulted in the highest population densities of M. arenaria J2. In 1993 , aldicarb reduced J2 densities in the soil but did not increase peanu t yields. Rotations of BP and CP reduced incidence of southern blight (Sclerotium rolfsii) in peanut, but neither CBP nor aldicarb affected the disease.