Narrowing in on Wide Row Cotton Spacing
October 18, 2022
With thinning margins across the Cotton Belt, interest in alternative row configurations has widened as a possible solution to increase profit per acre. The potential benefits of wide row spacing include lower seed costs, increased drought tolerance, lower incidence of boll rot, and improved harvest efficiency. However, these benefits depend on the growing environment and wide row spacing may not be the best fit for every farm.
The Southeast
In Alabama, where mid-season drought and late-season boll rot can be problematic, researchers at Auburn University are studying wider row spacing as a potential management tool. Initial studies comparing conventional 36-inch rows with 60- and 72-inch row spacings found that there was not enough growth to compensate for the wider rows, especially on Coastal Plains soils.1 Cotton planted on 48-inch rows in south Alabama demonstrated comparable yields to 36-inch rows with reduced seeding rates. Additional research is needed to understand the impact on hard lock and boll rot and how this system would perform on a high yield acre and under mid-season stress.2
Researchers at the University of Georgia tested three wide row spacings, 48-, 60-, and 72-inch rows with standard 36-inch rows and measured the impact of row spacing on cotton growth and development, fiber quality, and yield. Height, total nodes, nodes above white flower, nodes above cracked boll, and the percent of open bolls were comparable between the row spacings in this study. Standard 36-inch row spacing yielded the highest, followed by 48-, 60-, and 72-inch spacings. No fiber quality differences were observed between the row spacings. The lower input costs associated with the wider row spacings did not compensate for the yield reductions and did not provide a larger net return than standard practice.3,4
Research at North Carolina State University indicated that a yield penalty results from ultra-wide row spacing (72-inch rows) and was not an effective means to maximize returns as compared to standard 36-inch rows. However, cotton planted in 2-and-1 or 4-and-1 skip rows may have an economic advantage for some growers. Cotton planted in a 2-and-1 skip row uses standard (36- or 38-inch) row spacing with every third row not planted. In 4-and-1 skip rows, every fifth row is not planted. This approach may help lower input costs, but not for every farm or every year. This information is based on one year of study, where yields were higher than average. Research is ongoing to determine if skip row cotton is an option for North Carolina growers.5
The Midsouth
Trials at Louisiana State University compared 40- and 60-inch row spacing with and without cover crops. Initial results determined that including a cover crop for weed control for wider rows was not necessary with adequate residual herbicide application. The wider row spacing produced a shorter, wider cotton plant. Multiple, low rate, plant growth regulator (PGR) applications are necessary to help control vegetative growth, and higher rates of nitrogen (N) may be required based on the yield goal. Wide row spacing may not be suitable for all soil types, especially clay soils in a wet year.1,6 Delayed planting may become problematic as wide row cotton typically matures later than standard planted cotton. Planting on time is important to help avoid additional yield loss and complications with defoliation. Additional questions about the impact on fiber quality are currently being addressed through further research.6
In northeastern Louisiana, some growers have had success with 60-inch-wide rows as an option to continue growing cotton in the area. The reduction in seed and inputs costs can help make cotton production viable. Using precision equipment, whether built by a manufacturer or fabricated on the farm, can help reduce chemical expenses. A 60-inch row spacing may help with equipment efficiency for corn and soybean growers on 30-inch rows as well as maintain beds for another season when rotating crops, which can help improve soil quality.6
In 2019, the Bayer Learning Center at Scott, Mississippi evaluated different row spacings for growth control and yield potential. Three row configurations were planted: solid planted 38-inch rows, 38-inch 2-and-1 skip rows, and 76-inch row spacing. Vegetative growth control potential was observed to be higher and easier to manage in the 2-and-1 skip row and 76-inch row spacings. All row configurations tested had competitive yield potential, with the 38-inch solid row spacing having the highest average yield of the study.7 These row spacings were evaluated again in 2021 with four seeding rates: 20,000, 30,000, 40,000, and 50,000 seeds per acre. For this study, yield potential was optimized around 30,000 to 40,000 seeds per acre. It was observed that yields were not greatly impacted by lower seeding rates for the 38-inch solid row spacing. The 76-inch-wide row spacing had slightly higher yields at lower seeding rates, but still lower than the 38-inch solid row spacing. Wider row spacing produced acceptable yields in these studies; however, yield potential may be limited when compared to solid plantings.8
The West
Growing cotton on ultra-wide row spacing may be particularly useful for growers in water limited areas. One grower in the Panhandle of Texas has been transitioning from 40-inch cotton to 80-inch cotton to reduce plant stress during periods of drought. No-till and cover crops like cereals and radishes also help with water retention. Plant spacing and avoiding skips is critical at low seeding rates. Investing in precision planting equipment and selecting high quality cotton seed can help with planting efficiency. If the field is irrigated, then water application should be delayed to give the plants time to establish a larger root system. Some success has been observed with lowering N application and increasing calcium application. More passes in the field may be necessary with this system for micronutrient and PGR applications. PGRs should be applied early, frequently, and consistently.9
Wider row configurations are not the best fit for every farm but may have a use for certain situations. If the objective is to lower seed costs, it may be possible to lower seeding rates without making a larger management change to wider rows. Texas A&M scientists analyzed 15 internationally published studies and determined that yield reductions were not observed until plant populations fell below 15,000 plants per acre. This is the total plant population (plants per acre), not the seeding rate (seed per acre). With ideal planting conditions and seed quality with a minimum of 80% germination, it may be possible to make a reduction in seeding rate without a reduction in yield.10
Sources
1 Steadman, J. 2022. Thinking outside the traditional row. Cotton Grower. https://www.cottongrower.com/cotton-production/thinking-outside-the-traditional-row/.
2 Brown, S.M. 2022. 48-inch row spacing in cotton in south Alabama. 2022 Beltwide Cotton Conference.
3 Lawton, C., Snider, J., Roberts, P., Liu, Y., Chee, P., Hand, C. 2022. Evaluating wide row production systems in Georgia. 2022 Beltwide Cotton Conference.
4 Lawton, C., Snider, J., Roberts, P., Chee, P., Hand, C. 2022. Impacts of wide row spacings on yield components of cotton. 2022 Beltwide Cotton Conference.
5 Hart, J. 2022. Can ultra-wide-row cotton work in North Carolina? Farm Progress. https://www.farmprogress.com/cotton/can-ultra-wide-row-cotton-work-north-carolina/.
6 Rowsey, G. 2021. Producers see big savings with wide-row cotton. Delta Farm Press. https://www.farmprogress.com/cotton/producers-see-big-savings-wide-row-cotton/.
7 Row configurations in cotton production. 2020. Bayer. https://www.dekalbasgrowdeltapine.com/en-us/agronomy/row-configurations-cotton-production.html.
9 Huguley, S.E. 2022. Verett’s wide row cotton proves less is more. Farm Progress. https://www.farmprogress.com/cotton/veretts-wide-row-cotton-proves-less-more/.
10 Brown, S. 2021. Alabama cotton seeding rate trial summary. AgFax. https://www.agfax.com/2021/04/19/alabama-cotton-seeding-rate-trial-summary/.
1410_56651
