|Bauer, Philip - Phil|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2004
Publication Date: 3/1/2005
Citation: Bauer, P.J., Frederick, J.R. 2005. Tillage effects on within-canopy cotton fiber properties on two soil types. Crop Science. 45:698-703. Interpretive Summary: A greater understanding of how soil management practices affect cotton fiber quality will help researchers develop improved cotton growing systems with lint that has higher value. We studied how the soil type that the crop is grown on and the tillage practices used to produce the crop affect fiber properties at specific locations within the crop canopy. We found that fibers at specific positions within the canopy differ in length and in micronaire (similar to fiber thickness) between conventional and conservation tillage when rainfall was limiting during boll development. We also found that the range of micronaire values within the canopy was greater on the soil that was more susceptible to drought. This information will be useful to scientists developing cotton production systems with improved fiber quality.
Technical Abstract: The benefits of conservation tillage on soil water availability are well established. The objective was to determine whether soil management practices affect within-canopy cotton (Gossypium hirustum L.) fiber properties on two soils. A three-year field study was conducted with plots on two soil types [Bonneau loamy sand (loamy, siliceous, thermic Arenic Paleudult) and Norfolk loamy sand (fine-loamy, siliceous, thermic Typic Kandiudult)]. Treatments in the study were cover crop [none and rye (Secale cereale L.)] and tillage system (disk tillage and no-tillage). Yield and fiber properties of the whole crop were determined after machine harvesting. Fiber properties were also determined from hand picked samples at three canopy positions (first sympodial position bolls at mainstem nodes 6 and 7, 9 and 10, and 12 and 13). In two of the three years, no-tillage had 34% higher yield than disk tillage. No-tillage had higher fiber length uniformity every year, but no consistent differences between tillage systems occurred for the other fiber properties. Cover crop did not influence within-canopy fiber properties. When differences occurred between tillage systems for fiber length at specific canopy positions, fibers from no-tillage were about 1 mm longer than fibers from disk tillage. Fiber length uniformity results mirrored those for fiber length. Disk tillage resulted in cotton with 0.22 lower micronaire units than no-tillage at mainstem nodes 6 and 7 when rainfall was plentiful in 1997 but had micronaire that was 0.82 units higher than no-tillage at that canopy position during the dryer year of 1998. Within canopy variability for micronaire was greater on the more drought susceptible Bonneau soil than on the Norfolk soil. Tillage management and soil type need to be considered in developing long-term strategies aimed at increasing cotton processing quality.