Effect of Harvest Conditions and Leaf Hairiness on Fiber Quality

Environmental conditions during cotton harvest, specifically relative humidity, play a critical role in scheduling harvest operations.  It is common for producers to halt stripper harvest when humidity levels reach 50%.  The results of preliminary work performed in 2016 illustrated the strong positive relationship between relative humidity at the time of harvest and moisture content of stripper harvested seed cotton.  There was also a slight though significant impact on fiber uniformity and strength, both of which were reduced when cotton was harvested under elevated relative humidity.  This study was expanded in 2017 to include a picker-harvested location in south Texas and a stripper-harvested location in the Texas High Plains.  Harvest was timed around two timings or conditions, one with optimal or low humidity, and another harvest during elevated humidity.  Four cultivars were included in the study, the smooth leaf cultivars FiberMax 1830 GLT, and NexGen 3522 B2XF, and the semi-smooth or hairy cultivars Deltapine 1522 B2XF and PhytoGen 333 WRF.  The actual level of hairs or trichomes was determined by quantifying the number of trichomes per square centimeter of leaf or bract surface.  The objective of this study was to determine the impact of environmental conditions at harvest, namely humidity, in conjunction with varying levels of leaf hairiness or trichome density of commercial cotton cultivars, on the fiber quality of stripper and picker harvested cotton.