Impact of Environmental Conditions and Variety on Seed Coat Fragment Issues in Georgia in 2020

Abstract

In 2020, there were an abnormal number of seed coat fragment (SCF) reports from cotton produced in Alabama, Georgia, and Florida resulting in price deductions of more than $23 million in the region and $18 million in Georgia alone based on loan value. To understand what led to the historic number of SCF calls, variety trial samples from Georgia were evaluated for SCF issues. Trials were conducted across 24 locations in Georgia and included 12 varieties. A total of 286 seedcotton samples were ginned at the UGA Microgin in Tifton, GA, and two fiber samples were collected, one for High Volume Instrument and one for Advanced Fiber Information System (AFIS) analysis, and a seed sample was collected for free fatty acid (FFA) analysis. None of the samples sent to the Memphis, TN classing office received an extraneous matter call; however, there were differences in AFIS seed coat nep (SCN) counts, trash, and FFA when evaluated by site and variety. Variety was not as impactful as location, indicating that environmental differences between sites were responsible for the differences. As more rainfall occurred from first open boll to harvest, SCN count increased. Additionally, as average daily solar radiation increased, SCN count decreased. Therefore, it was determined that significant and prolonged weathering is what likely led to the outbreak of SCF issues in the Southeast. Future research should continue to evaluate environmental impacts on the occurrence of extraneous matter as well as an objective method to determine extraneous matter occurrences in cotton lint.