The effect of seed cotton moisture during harvesting on – part 1 – fiber quality

Abstract

It is generally accepted that harvesting and storing of seed cotton above a moisture content of 12% prior to ginning will compromise fiber quality. This advice stems from research conducted on harvesting seed cotton with the conventional basket and separate module building system, which produces large rectangular modules. It is hypothesized that the 12% moisture content limit will also hold true for harvesting seed cotton in a high-production system using alternative harvesters. The latest generation of harvesters, such as the John Deere (JD) 7760 spindle harvester with on-board module building capacity producing smaller round modules, have greater horsepower, traction and fan capacity, which enables them to harvest cotton when field conditions would have made harvesting difficult with conventional systems. This study examined the fiber quality of saw ginned Upland cotton, harvested from one field using a JD 7760 at two moisture levels, <12% and >12%, and storing the harvested modules for 12 weeks prior to ginning. There was a significant difference between the two moisture levels for fiber color, with seed cotton harvested at >12% resulting in fiber that was yellower, with lower reflectance and a color grade of 52, compared to a 51 grade for seed cotton harvested at <12% treatment. The seed cotton harvested at >12% had more trash with a leaf grade of 3, compared to a leaf grade of 2 for the seed cotton harvested at the <12% level. There was no significant difference between the two moisture levels in terms of fiber length and strength, but fiber micronaire was higher for the higher moisture content. There was no significant difference between the moisture levels for total nep count, but the seed cotton harvested at >12% had larger neps and more seed coat neps.