Cotton yield and quality response to row pattern, seeding rate

Authors: Sorensen, Ronald - Ron; Lamb, Marshall; Butts, Christopher - Chris

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2022
Publication Date: 8/1/2022
Citation: Sorensen, R.B., Lamb, M.C., Butts, C.L. 2022. Cotton yield and quality response to row pattern, seeding rate. Journal of Cotton Science. 26:66–75. https://doi.org/10.56454/QLIP5101.
DOI: https://doi.org/10.56454/QLIP5101

Interpretive Summary: Cotton is grown on about 2.22 million acres in the tri-state area of Alabama, Florida, and Georgia. Cotton is grown in rotation with corn (Zea mays L), peanut (Arachis hypogaea L.), soybean (Glycine max L.), sorghum (Sorghum bicolor L.) and wheat (Triticum aestivum L.). However, the major cropping sequence in the Southeast would be cotton, corn, and peanut with multiple years of either cotton or corn. Cotton is typically planted in single rows. Peanuts are typically planted in twin-rows for greater yield and grade. Planting cotton in a twin-row pattern would increase distance between individual plants and may increase yields. Therefore, it would be cost effective to use a twin-row planter typically used for peanut, for both corn and cotton. The effect of row pattern, i.e., twin-row on the yield or grade of cotton, seems to depend on location, soil type, irrigation system selection, climatic patterns, or other management criteria. However, no research was done using S3DI in comparison with SSDI or sprinkler systems. In addition, most researcher increased the rate of plant population or slightly lower than recommendation, but none had plant populations were at half the recommended rate. Irrigation systems can apply water to the soil to reduce the effects of drought during the growing season. Also, the type of irrigation system, either drip or sprinkler irrigation, may influence yield of these crops. Therefore, the objectives of this research were to document cotton yield and quality when: 1) planted in twin-rows, 2) plant densities at recommended and half-recommended rates, and 3) with various irrigation systems (sprinkler or drip). Research treatments were similar across all sites, soil series, and irrigation systems. There were two row patterns of single and twin-row. The single rows were space 3 ft apart using a double disk opener vacuum planter at recommended seeding depth. Twin-row planting was accomplished using GPS by shifting the tractor 3 inches to the left and right of the 3-ft, to get a six-inch middle between the twin-rows. Seeding rates were at recommended (36,400 seeds/ac) and half-recommended rates (18,200 seeds/ac). Pesticides were applied at recommended times and rates as suggested by manufacture’s practices and on-site field scouting. Irrigation scheduling was accomplished using electronic soil moisture sensors and meteorological data estimating the crops evapotranspiration. Cotton was harvested using a 2-row commercial cotton spindle picker. Total cotton from each plot was weighed, recorded, and a sub-sample was collected for lint out-turn and quality parameters. All data were analyzed with the analysis of variance (ANOVA) and all-pair wise multiple comparisons. ANOVA showed that yield data were significantly different by year and/or location; therefore, each year and location were analyzed separately. Fiber yield along with fiber characteristics were analyzed by row pattern, seed population, and row pattern by seed population interaction. There was no yield effect for row spacing by seed population interaction. There were some fiber characteristic differences across years, locations, and irrigation systems for fiber length, strength, micronaire, and uniformity. However, there was no consistency in any of these characteristics across treatments to be able to draw any conclusions for the fiber characteristics measured. Any significant difference in values due to treatments were not great enough to cause any economic deductions to the lint value. Overall, planting with either single or twin row does not affect yield. Also, the use of drip or sprinkler systems does not seem to affect yield. The decision to plant at a lower rate may have a seed savings but may not always cover the possible loss of yield with the lower planting population.

Technical Abstract: Cotton (Gossypium hirsutum L.) is a major rotational crop associated with peanut (Arachis hypogaea L.) cropping systems in Southwest Georgia. Since peanut is typically planted in twin-rows for greater yield and grade, use of the same twin-row planter for cotton would be cost effective. It is not clear what effect row pattern would have on cotton lint yield. The objectives were to compare cotton yield when planted in different row patterns, with two plant densities, at multiple locations, and irrigated with drip or sprinkler irrigation systems. Cotton was planted in single and twin-row patterns at recommended and half-recommended seeding rates (90,000 and 45,000 seeds/ha, respectively) at multiple locations and cropping seasons. Irrigation systems were subsurface drip irrigation (SSDI), shallow subsurface drip irrigation (S3DI), and overhead sprinkler. Row pattern (single or twin-row), seeding rate, or irrigation system had no effect on lint yield. There were some fiber characteristic differences but there was no consistency to draw any conclusions. Cost savings from planting at half-recommended seeding rate ranged from $-55/ha to over $136/ha depending on year and location, covering the loss of yield and revenue 66% of the time. For consistent year-to-year yield and economics, it is recommended to plant cotton at recommended seeding rates using single or twin-rows with either drip or sprinkler irrigation systems. Reducing seeding rates less than recommended may increase risk of lower yields and revenue that may not be covered by money saved using less seed.