Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 3/24/2004
Publication Date: 9/20/2004
Citation: Young, L.D., Pettigrew, W.T., Bruns, H.A., Stetina, S.R. 2004. Suppression of reniform nematode populations with cotton-corn rotations. Journal of Nematology. Volume 36, Page 354. Interpretive Summary:
Technical Abstract: The reniform nematode, Rotylenchulus reniformis, has become the predominant phytoparasitic nematode on cotton (Gossypium hirsutum) in Mississippi and Louisiana. Corn (Zea mays) is a nonhost and has potential to reduce the nematode's population size. Corn as a rotation crop was evaluated in a field study conducted from 2000 through 2003 at Stoneville, MS. The experimental design used was a randomized block split-plot with eight replications. The main plots were crop rotations (continuous cotton, cotton-corn-corn-cotton, corn-cotton-corn-cotton, or continuous corn), and subplots were one of four cultivars of either corn or cotton. Subplots were 6 rows spaced 102 cm apart by 7.6 m long. Nematode populations in the center 2 rows of each subplot were determined at planting, midseason, and harvest. These same rows were harvested for yield determination. Nematode populations at planting in plots planted to cotton the previous season (mean 5364/L) exceeded the action threshold of 2200/L for Mississippi, regardless of rotation sequence. When cotton followed one season of corn, nematode populations rebounded by the end of the season. However, nematode populations remained below damaging levels throughout the season in cotton following two seasons of corn. The crop rotation effect was significant at P=0.06 during 2003, when cotton lint yield from the cotton-corn-corn-cotton rotation was 194 kg/ha greater than yield from the continuous cotton plots. Rotation did not impact corn yield. At these nematode population levels, a rotation with at least two consecutive years of corn appears to be necessary to achieve reniform nematode suppression sufficient to increase cotton yield.