Impact of Soil Applied Potassium on Cotton Yield, Quality, and Plant Growth in Texas

In recent years, various areas in the Texas Blacklands and Gulf Coast agricultural production regions have reported increased incidence of potassium (K) deficiencies in cotton. Cotton, specifically, is sensitive to low potassium levels reducing yields and fiber quality, as well as making the cotton plant more susceptible to some foliar diseases. In 2013 and 2014, eight locations were chosen to conduct trials on the rate of potassium applied to cotton, as well as the application methods.  These sites ranged from low (60 ppm) to high (350 ppm) potassium levels in the soil. Treatments included four rates of granular (0-0-60) broadcasted and incorporated and five rates of liquid (0-0-15) injected fertilizer, as well as, untreated plots. In-season data collection included: plant height, nodes to first fruiting branch, total nodes, and leaf tissue sampling. The plots were harvested by various means, depending on the location. After harvesting was completed, samples were weighed and ginned. Lint samples were sent to Cotton Inc. to test fiber properties by HVI and AFIS analysis. The 2014 trials were non-responsive to the treatments at these two locations, unlike the 2013 trials which had a positive correlation between the amount of fertilizer and application method and yield.