Making the Replant Decision: Predicting Yield and Fiber Quality in the Mid-South from Planting Date and Population

Abstract

Cotton producers in the U.S. Mid-South often plant in cool, wet conditions to lengthen the growing season and maximize yield potential. Although multiple studies have been conducted to determine optimum planting windows and seeding rates, few studies have evaluated the interaction of these parameters. To make a replant decision, the yield potential of the current stand versus the yield potential of the replant must be estimated. The objective of this study was to determine the impact of plant population and planting date on lint yield and fiber quality. Field experiments were conducted in 10 site-years from 2016 to 2018 in Tennessee, Mississippi, and Missouri. Treatments included five seeding rates (10.5, 6.75, 3, 1.5, and 0.75 seeds m-1) and multiple planting dates (typically early May, mid-May, and early June). Although yields were lowest at later planting dates and low populations, results suggested a uniform population of 74,000 plants ha-1 will not warrant a replant at any date, and uniform populations as low as 49,000 plants ha-1 planted after 5 May also will not warrant replanting. Fiber quality was impacted by environment and planting date, with micronaire decreasing and length, strength, and uniformity increasing as planting date was delayed. These data will assist with replant decisions by providing estimates of the current stand relative to the yield potential of a successful (or unsuccessful) replant. Furthermore, results suggest producers could reduce seeding rates at later planting dates without reducing yield potential.