Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: February 12, 2010
Publication Date: April 26, 2010
Citation: Wanjura, J.D., Kelley, M.S., Boman, R.K., Holt, G.A. 2010. Harvest timing and techniques to optimize fiber quality - Initial findings. In: Proceedings of the Beltwide Cotton Conferences, January 4-7, 2010, New Orleans, LA. 2010 CDROM. p. 539-550. Interpretive Summary: Since 2008, Texas cotton production has accounted for almost 50% of the US crop. Production conditions in the Texas High Plains region, where most of the Texas crop is produced, can limit fiber maturity resulting in fiber with elevated nep and short fiber content. Further, harvesting and ginning practices can increase nep and short fiber levels, resulting in reduced ring spinning performance. Research is needed that focuses on improved harvesting methods for preserving fiber quality from the field to the gin. Providing cleaner, higher quality seed cotton to the gin helps reduce ginning costs and increase lint value to the producer. This work investigates novel harvesting techniques using conventional harvesting equipment applied at different stages of final crop maturity to optimize fiber quality. Harvesting treatments included 1) spindle picker applied at 80% open bolls then again at 100% open bolls (pick then pick), 2) spindle picker applied at 80% open bolls followed by a brush-roll stripper at 100% open bolls (pick then strip), 3) spindle picker applied at 100% open bolls (conventional pick), and 4) a brush-roll stripper applied at 100% open bolls (conventional strip). Results indicate that non-color fiber quality parameters were improved for the initial picker harvest events conducted at 80% open bolls. However, economic comparison of the treatments indicated that the conventional pick treatment resulted in significantly higher net return than the pick then strip treatment. The conventional strip and pick then strip treatments were not different from any other treatments with regard to net income. The crop used in this study produced relatively mature fiber. Future studies will evaluate treatment effects on crops with less mature fiber.
Technical Abstract: Production conditions typical to the Texas High Plains region can produce cotton crops with high short fiber and nep content, both of which have a detrimental impact on ring spinning performance. Since Texas now produces nearly 50% of the US cotton crop annually, it is critical that research focuses on finding ways to maximize fiber quality in order to improve the competitiveness of US cotton on the world market. The objectives of this work are to document the within-plant distribution of yield, fiber quality, and lint value for a well irrigated High Plains cotton crop; investigate differences in fiber quality from cotton harvested with conventional equipment applied at different levels of final crop maturity; and evaluate the economic feasibility of using new techniques with conventional harvesting equipment to maximize fiber quality. Four harvesting treatments were investigated in this work: 1) picker harvest at 80% open bolls followed by a second picker harvest once all bolls were open, 2) picker harvest at 80% open bolls followed by a subsequent stripper harvest once all bolls were open, 3) conventional picking, and 4) conventional stripping. The findings of this work indicate that non-color fiber quality parameters can be improved through using a spindle picker at approximately 80% open bolls prior to defoliation. Lint value was decreased for these treatments due to poor color grades resulting from the presence of green leaf trash with high moisture content. A basic economic comparison of harvesting treatments indicated the highest net return for conventional picking but no significant difference was observed between conventional picking, conventional stripping, or the treatment using the picker at 80% open bolls prior to defoliation and then again once 100% open bolls were achieved. The harvest treatment using a picker at 80% open bolls prior to defoliation and then a brush-roll stripper at 100% open bolls after crop desiccation returned the lowest net value and was significantly lower than the conventional pick treatment.