Effects of crop rotation and nonfumigant nematicides on peanut and corn yields in fields infested with criconemella species.

The effects of nematicide treatments and corn-peanut cropping sequences on the population development of Criconemella ornata, and C. sphaerocephala and the related impact on crop yields were investigated at two North Carolina locations. Criconemella ornata and C. sphaerocephala were present at the Norman Perry farm, Bertie County (BERTIE); however, only C. ornata was found at the Central Crops Research Station, Johnston County (CCRS). An untreated control was compared to aldicarb 15G, carbofuran 15G, ethoprop 10G, and terbufos 15G granular formulations applied at a rate of 2.2 kg a.i./ha. The cropping sequences were monocuhured corn (C-C-C); monocultured peanut (P-P-P); and two corn-peanut (C-P-C; P-C-P) rotations. Nematicides were inconsistent in controlling C. sphaerocephala and C. ornata. Nematicide treatments enhanced corn yields in the monoculture-cropping cycle in the final year of the experiment at CCRS. Peanut yields were greater in the rotated cropping sequence than under monoculture at BERTIE, but rotation had less effect on peanut yields at CCRS. Declining yields were correlated with an increase in numbers of nematodes. Corn was an intermediate host for C. sphaerocephala and a moderate to poor host for C. ornata. Peanut was an excellent host for C. ornata and a poor host for C. sphaerocephala.