Upland Cotton Growth and Yield Response to Enhanced Inputs Across the Mid-south and Southeast Cotton Belt

Abstract

In addition to cost of seed and agrichemicals, cotton growers are often enticed to apply additional inputs in the quest for plant health. It is not known, however, whether these additional inputs are cost effective. The objectives of this study were to evaluate current extension recommendations compared to several additional inputs on yield and economic gain. In addition, differences in plant populations, plant heights and thrips damage were assessed. Additional inputs included enhanced soil fertility, in-furrow and foliar fungicides, in-furrow insecticide, and late foliar applied potassium. Each of the inputs was included as an individual treatment, a combined treatment with all five inputs, and a control treatment based on each state’s extension recommendations in the trial. Each treatment was included at both an early and late planting date from 2014 through 2016 in Missouri, Mississippi, North Carolina, and Virginia. No additional inputs increased fiber yield or economic gain significantly compared to the controls. Plant populations and plant heights at five weeks after planting (WAP) were not influenced by inputs except for a reduction in plant population of the 150% fertility treatment when compared to local extension recommendations in 2016. Thrips injury rating at three WAP was reduced by treatments including the in-furrow insecticide compared to the control in two of three years in both North Carolina and Virginia The data indicate that these additional inputs are for use under specific circumstances or thresholds and should not be used as a blanket agronomic treatment in the name of plant health.