Row and plant spacing effects on growth and yield of dryland cotton where growing season duration is limited

Authors: Baumhardt, Roland - Louis; Schwartz, Robert; Marek, Gary; BELL, JOURDAN - Texas A&M Agrilife

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/3/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: As water from the declining Ogallala Aquifer becomes scarce, sustainable dryland farming may replace irrigated production. Cotton is a good dryland crop, but the limited growing season on the Southern High Plains limits yield. Scientists from ARS in Bushland, Texas and Texas A&M AgriLife Research and Extension Service field tested row and plant spacing effects on cotton fiber quality and yield. Early and regular maturing cotton varieties grown in narrow, 10 to 20 inches, rows were shorter and had fewer bolls per plant than normal 30 inches rows. Row width and plant spacing did not usually affect fiber quality premiums. These results show farmers and crop consultants that dryland cotton planted using narrow rows and plant spacing yielded the same or less lint of similar fiber quality than for normal 30 inches rows.

Technical Abstract: Irrigation water availability is decreasing in the Southern Great Plains due to continued pumping from the Ogallala aquifer. Cotton (Gossypium hirsutum L.) is a profitable alternative crop suited to sustainable dryland production. However, the growing season of the Texas Panhandle and southwestern Kansas is often energy limited, which may increase the production risk by limiting fiber maturation and yield. We hypothesized that marginal cotton yield produced from earlier bolls could be offset by increasing plant population using narrower row or plant spacing. Our objectives were to quantify (i) row width and (ii) plant spacing effects on the growth, yield, and fiber quality of dryland cotton. Field tests comparing planting row widths from 0.25 to 0.76 -m and plant spacing of 0.075, 0.10, and 0.15 – m for populations of 8.8 – 26.7 plants per square meter were conducted from 1999 to 2005 on a nearly level Pullman clay loam (fine, mixed, superactive, thermic Torrertic Paleustoll) managed in a wheat (Triticum aestivum L.), cotton, fallow (W-Ctn-F) rotation. Drought conditions prevented crop establishment in 2002 and in 2005 the crop was destroyed by hail. Plant height, boll number and lint yield increased significantly during most years as the space between rows but not plants increased. This wider row spacing benefit was observed for the short season cultivar more frequently than for full season cultivars. Our data also show that planting semiarid dryland cotton in narrow rows to increase plant population often reduced fiber quality and market value compared with conventional 0.76 m rows.