Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2007
Publication Date: 12/31/2007
Citation: Stetina, S.R., Young, L.D., Pettigrew, W.T., Bruns, H.A. 2007. Effect of Corn-Cotton Rotations on Reniform Nematode Populations and Crop Yield. Nematropica. vol. 37:237-248 Interpretive Summary: The reniform nematode has become the predominant nematode damaging cotton in the Mid South area of the United States. Reniform nematodes are not able to grow and reproduce on corn, so this crop was grown in rotation with cotton to see if it could reduce the number of reniform nematodes in the field. Continuous cotton, continuous corn, corn-cotton-corn-cotton, and cotton-corn-corn-cotton sequences were compared. When cotton followed one season of corn, nematode populations started out low but increased to damaging levels by the end of the season. However, nematode populations remained below damaging levels throughout the season in cotton following two seasons of corn, and cotton lint yields increased with this rotation sequence. Corn yields were either not affected or, in one year, improved when the crop was grown in rotation with cotton. Rotation with corn can be an effective management tool for growers working to suppress reniform nematode populations in cotton.
Technical Abstract: Corn (Zea mays) as a rotation crop with cotton (Gossypium hirsutum) was evaluated in a field study conducted from 2000 through 2003 at Stoneville, MS to determine its impact on reniform nematode (Rotylenchulus reniformis) populations. The experimental design used was a randomized block split-plot with eight replications. The main plots were crop rotations (continuous cotton, continuous corn, corn-cotton-corn-cotton, or cotton-corn-corn-cotton), and six-row subplots were one of four genotypes of either corn or cotton. Nematode populations in the center two rows of each subplot were determined at planting, midseason, and harvest. Cotton and corn yields were determined from samples taken from one or all four of the inner subplot rows, respectively. Nematode populations at planting in plots planted to cotton the previous season exceeded the action threshold for Mississippi, regardless of rotation sequence. Nematode populations remained below damaging levels throughout the season in cotton following two seasons of corn. However, when cotton followed one season of corn, nematode populations rebounded by the end of the season. Cotton lint yield from the cotton-corn-corn-cotton rotation was 194 kg/ha greater than yield from the continuous cotton plots in 2003 (P = 0.065). At the nematode population levels in this study, a rotation with at least two consecutive years of corn appears to be necessary to achieve reniform nematode suppression sufficient to increase cotton yield. Corn yields were either not affected or, in one year, improved when the crop was grown in rotation with cotton.