|Durant, John - CLEMSON UNIV.|
|Frederick, James - CLEMSON UNIV.|
Submitted to: Annual Southern Conservation Tillage Conference for Sustainable Agriculture
Publication Type: Proceedings
Publication Acceptance Date: March 15, 1998
Publication Date: N/A
Interpretive Summary: There can be substantial differences in cotton growth and yield within cotton fields in the southeastern USA. This report describes preliminary findings from a study designed to determine whether implementing soil management techniques that improve soil water conditions (conservation tillage) and uniformly applying an insecticide/nematicide at planting reduce the amount of within-field variability for lint yield and fiber properties. We found that the amount of variability for yield and micronaire was the same for cotton grown with conventional and conservation tillage. The amount of variability for fiber length and for fiber strength was lower for cotton grown with conservation tillage than for cotton grown with conventional tillage. Pesticide application did not influence the amount of variability for yield, micronaire, fiber length, or fiber strength. The yield response to application of the pesticide was greater in conventional tillage than in conservation tillage. This information is useful to scientists working on finding ways to reduce the amount of variability in fiber properties in the raw cotton used by mills and to scientists designing best management practices for site-specific farming.
Technical Abstract: There is considerable variability for lint yield within cotton (Gossypium hirsutum L.) fields in the SE Coastal Plain. The objective of this experiment was to determine if soil management techniques and in-furrow application of an insecticide/nematicide influence the amount of variability in cotton yield and fiber properties. Treatments in the study were tillage (conservation vs. conventional) and aldicarb application (1.07 lbs a.i./acre vs. none). In 1997, DPL Acala 90 was planted into large plots that spanned across several soil map units. Two harvesting methods were used to determine variability. First, the large plots were subdivided into 44-ft-long sections and two of the rows in each section were harvested with a spindle picker. Second, a 6-foot sample was hand-harvested from each of three soil map units (Bonneau sand, Eunola loamy sand, and Norfolk loamy sand) within each plot. Neither aldicarb application nor tillage system affected the variability for yield or micronaire among the machine-harvested samples. Variability for fiber length was less in conservation tillage than in conventional tillage only when aldicarb was applied. For fiber strength, conservation tillage had lower variability than conventional tillage for the plots without aldicarb. Soil map unit was responsible for much of the variation in yield, with the Bonneau sand having lower yield. Variability for fiber properties was less than variability for yield.