Research Project: Enhancing the Profitability and Sustainability of Upland Cotton, Cottonseed, and Agricultural Byproducts through Improvements in Pre- and Post-Harvest Processing

Location: Cotton Production and Processing Research

2020 Annual Report

Objectives
Objective 1: Enable, from a technological standpoint, new commercial equipment and processes for harvesting, storing, and pre-processing Upland cotton; resulting in (1) lower use of chemicals, and (2) enhanced cleanliness and quality of the seed cotton, cottonseed, and/or lint fiber. Subobjective 1A: Develop technology for chemical free cotton pre-harvest defoliation and desiccation treatments. Subobjective 1B: Develop sensing technology for monitoring/control of cotton during harvest operations. Subobjective 1C: Evaluate the accuracy of microwave sensor based cotton yield monitoring systems and investigate the relationships between yield measurement error and crop characteristics and environmental parameters. Subobjective 1D: Develop technology for improving the accuracy and reliability of cotton yield monitor data. Subobjective 1E: Develop technology for improving the cleanliness of harvested seed cotton and the efficiency and productivity of cotton harvest. Objective 2: Enable new commercial technologies and methods for post-harvest processing of stripper-harvested seed cotton, cottonseed, lint fiber and/or agricultural byproducts that preserve and/or enhance quality/value, storage, and utilization. Subobjective 2A: Develop sensing technology for identification and control of cotton gin moisture control systems. Subobjective 2B: Develop commercially viable means of delinting cottonseed, to produce planting quality (naked) seed, without the use of chemicals. Subobjective 2C: Develop and evaluate the use of cotton gin byproducts in the manufacture of composite materials. Subobjective 2D: Develop methods and technology for improving the quality and productivity of Southern High Plains cotton. Sub-objective 2E: Develop sensing technology for detection of contaminants in seed-cotton and cotton lint during post-harvest operations. Sub-objective 2F: Develop simulation models for use in enabling rapid development of cotton-gin based contamination removal machinery. Sub-objective 2G: Develop machinery for detection and removal of contaminants in seed-cotton during harvest operations. 3: Enhance the knowledge base pertaining to measurement, characterization, and estimation of non-combustion source particulate matter emitted from agricultural production and processing operations.

Approach
This five-year project plan addresses critical production, harvesting, and processing issues facing cotton producers and processors in the United States. Our plan of work is based on an interactive research approach which emphasizes the development of improved harvest preparation, mechanical harvesting, lint cleaning, cottonseed processing equipment, and in finding suitable uses for cotton byproducts and/or waste materials. The planned research targets two critical areas: 1) harvest, storing, and pre-processing technologies for Upland cotton, and 2) innovative post-harvest processing of seed cotton, cottonseed, lint fiber, and/or cotton byproducts and co-products. Commercial viability of the research is a key component of any problem solution.

Progress Report
This project is concluded, and the following is a five year summary of progress. Objective 1: A new chemical-free method for preparing cotton for mechanical harvest was developed. This work investigated the use of mechanical and thermal (flame and laser) techniques to girdle cotton stalks near the base of the plants thereby reducing nutrient and water transport and accelerating the process of natural senescence. The mechanical methods were very difficult to implement under field conditions and were considered infeasible for commercial cotton production. However, various thermal methods were explored that proved to be viable alternatives to chemical defoliation. The most successful of these was the use of directed propane flames to provide elevated temperatures necessary to boil the sap inside the stalks. In field testing trials, this method yielded a strong defoliation response with nearly zero regrowth. Current chemical defoliation methods struggle to provide adequate regrowth control when plants receive rainfall after defoliation but before a killing frost. Various methods for detection of field-based plastic contamination were explored with the objective to provide advanced warning in time to actuate a mechanical exclusion system that would prevent the plastic from being harvested. The two most promising methods developed utilized deep infrared thermal sensing of black plastic (materials heated by the sun to well above ambient and surrounding crop materials) and the use of visible color detection methods. The visible color detection method was more fully developed for use in detecting contaminants in seed cotton in the ginning process and additional work is ongoing to adapt this technology for harvester-based applications. Microwave sensor-based yield monitors were evaluated to determine accuracy in estimating cotton yields. Multiple large-scale, replicated cultivar testing locations were harvested with cotton strippers equipped with microwave yield monitors to collect data for the analysis. Yield monitor error was measured for each experimental plot by comparing the accumulated plot weight reported by the yield monitor to the total plot weight measured by a mobile reference scale system. Additional data were collected to investigate the relationship between yield monitor error and crop moisture content, foreign matter content, seed size, and fiber quality parameters. Results indicate that the microwave yield monitor system error is on the order of +/- 12% and is correlated with seed size and seed cotton moisture content. Recommendations for calibration were made to help growers minimize yield monitor errors. During the course of research on evaluating microwave yield monitor errors on cotton stripper harvesters, a new system was designed, fabricated, and field tested that provides yield monitor calibration data on the harvester without the need for expensive and often unavailable portable reference scales. An algorithm was developed to calculate seed cotton weight in the basket of the harvester as a function of basket position and hydraulic pressure in the basket lift cylinder hydraulic circuit. Custom electronics and hydraulic componentry were developed and implemented for field testing on multiple grower owned and operated cotton strippers. Field trial results indicate that the system is capable of producing accurate weight data with average error less than 1%. A new field cleaner was designed and tested for use on state-of-the-art cotton stripper harvesters. The new machine has increased material processing capacity and substantially improved cleaning performance compared to the current field cleaner used on stripper harvesters. In cooperation with a commercial partner, the machine was field tested over several years to ensure cleaning performance and reliability. The new field cleaner design has been slated by the commercial partner to become the production model field cleaner in the near future. Objective 2: Researchers developed a microwave moisture sensing system for seed cotton. The system was successfully field tested on micro-modules for determination of seed cotton moisture content. The work provides the basic physical properties of seed-cotton electrical permittivity necessary for sensor commercialization. The system was tested over a frequency range from 1-2 GHz which revealed the need for a multi-frequency approach to obtain the highest accuracy. The system was able to handle seed cotton micro-modules ranging in moisture content from 8% to over 20%, which covers the anticipated range of harvestable seed-cotton moisture. A bench-top mechanical cottonseed delinter was developed and tested for use in cotton breeding programs to eliminate the need for acid. The bench-top model was so successful that the technology was transferred to a local cotton gin manufacturing company for commercial sale. There have been four commercial units sold thus far, 3 domestically and one internationally. The bench-top model led to building an 8-ft prototype to evaluate the possibility of mechanically delinting cottonseed on a commercial-scale. A commercial-scale unit was built and will be installed in a commercial facility for evaluation. Several mycelium/agricultural substrate mixtures were evaluated as acoustic absorbers. During the evaluation, a modification to the 3-microphone method was developed to obtain faster readings with less technical equipment. The results from the testing were published showing the benefits of selecting agricultural substrates that complement each other. The new modification to the 3-microphone method was published and provides the acoustic industry a quicker more reliable measurement of reflective and through sound wave transmissions. A small-scale ginning system was designed and fabricated to augment cultivar development efforts of public and private cotton breeding programs. The new system incorporates seed cotton cleaning technology prior to the gin stand to remove foreign material and provide consistent, continuous seed cotton flow into the gin. The gin stand incorporates powered-roll technology which allows the system to operate without human interaction, which is a major benefit for worker safety, sample processing efficiency, and data consistency. After the gin stand, novel lint cleaning technology was included to further reduce lint foreign matter while minimizing fiber damage. Results of research conducted with the new ginning system indicate substantially improved reliability in lint turnout, seed production, and fiber quality parameters measured on commercial and experimental lines. The ginning system design has been transferred to a commercial gin equipment manufacturer for production and sale. A low-cost system for detecting and removing plastic contamination from seed cotton flowing down a gin feeder apron was developed. The design objective for this system was to develop a high-speed detection system that would provide a control signal in time for a subsequent removal system to eject the contamination from the cotton flow. After researching multiple detection technologies, a machine-vision approach utilizing cell-phone processors and color imagers was selected. A pneumatic removal system was designed and implemented at the base of the feeder apron to blow contaminants out of the seed cotton and onto the floor in front of the gin stand. This technology was developed and successfully demonstrated in multiple commercial field trials at several cotton gins. Testing results indicate the system is capable of 90% detection/removal efficiency on the feeder apron. Final evaluations were conducted in cooperation with two commercial partners who are now manufacturing and selling the systems into cotton ginning industry. During the course of the investigation, it was determined that a primary source of plastic contamination is large plastic inner tails from cylindrical cotton module wraps that inadvertently get into the cotton flow and then hang on the module-feeder dispersing cylinders. If the plastic is not quickly removed from the cylinders, normal operation of the cylinders against incoming cotton will cause the plastic to be continuously torn off in small pieces which can potentially contaminate hundreds of bales. To address this problem, an early warning detection system was developed that periodically monitors the cylinders that are normally obscured from view by incoming cotton. This system has proven valuable in alerting gin personnel that they have plastic on the cylinders in time for them to stop the gin before the majority of the potential contamination has had a chance to occur. A cooperating commercial gin utilizing the prototype reported a significant decrease in the number of plastic contamination calls from the USDA Cotton Classing Office compared to the previous year. Objective 3: Dispersion modeling input data on the mass of particulate matter (PM) per ton of bulk material for raw material and byproduct piles at nut processing facilities and cotton gins were developed. Samples of raw nut piles from a California almond processing facility and multiple Texas cotton gins were collected and subjected to sieving and particle size distribution analyses. Results of this work provided to stakeholders included estimates for the mass of total PM, PM10 (PM less than 10 microns in diameter), and PM2.5 (PM less than 2.5 microns in diameter) per ton of original material. In absence of these data, these parameters must be estimated by modelers often at levels far in excess of realistic levels which leads to over estimation of PM emissions from agricultural sources.

Accomplishments
1. Visual inspection plastic removal (VIPR) system developed to mitigate plastic contamination in cotton. Plastic contamination is the single largest threat to the U.S. cotton industry today. According to USDA Agricultural Marketing Service Cotton Classing Offices, most of the plastic contamination in lint samples from ginned cotton bales in the U.S. originates from plastic wrap material used around cylindrical or “round” modules formed by state-of-the-art cotton harvesters. Plastic contamination is the major reason for the loss of a premium that U.S. grown cotton once received on the international market for its reputation as a reliable source of contaminant-free natural fiber. On an annual basis, this loss of premium equates to a loss of revenue to the U.S. cotton industry in excess of $750 million. This problem affects all cotton producers – even if a producer has no cotton bales that receive a classing call for plastic contamination. Researchers in Lubbock, Texas, developed a low-cost system that identifies and removes plastic and other contaminants in seed cotton before the gin stand. This system, commercially known as VIPR (Visual Inspection and Plastic Removal), utilizes imaging sensors from the cell phone industry with low cost embedded microcontrollers to identify plastic in seed cotton before it flows into the gin stand. When a contaminant is detected, a pneumatic system is actuated to blow the contaminant out of the seed cotton and onto the floor in front of the gin stand. Commercial testing shows that the system can operate with detection/removal efficiency in excess of 90%. The technology was developed, tested, and successfully transferred to a commercial partner and is now being sold domestically and internationally. This system has the ability to save the U.S. cotton industry over $1 billion over the next decade.

Review Publications
Pelletier, M.G., Wanjura, J.D., Holt, G.A. 2019. Electronic design of a cotton harvester yield monitor calibration system. AgriEngineering. 1:523–538. https://doi.org/10.3390/agriengineering1040038.
Pelletier, M.G., Wanjura, J.D., Holt, G.A. 2019. Embedded micro-controller software design for a cotton harvester yield monitor calibration system. AgriEngineering. 1(4):485-495. https://doi.org/10.3390/agriengineering1040035.
Pelletier, M.G., Preston, S.C., Cook, J.A., Tran, K.D., Wanjura, J.D., Holt, G.A. 2019. Thermal performance of double-sided metal core PCBs. AgriEngineering. 1(4):539-549. https://doi.org/10.3390/agriengineering1040039.
Pelletier, M.G., Wanjura, J.D., Holt, G.A. 2019. Man-machine-interface software design for a cotton harvester yield monitor calibration system. AgriEngineering. 1(4):511-522. https://doi.org/10.3390/agriengineering1040037.
Shojaeiarani, J., Bajwa, D., Holt, G.A. 2020. Sonication amplitude and processing time influence the cellulose nanocrystals morphology and dispersion. Nanocomposites. 6(1):41-46. https://doi.org/10.1080/20550324.2019.1710974.
Pelletier, M.G., Wanjura, J.D., Holt, G.A., Greetham, L., Kaplan-Bae, J., McIntyre, G., Bayer, E. 2019. Acoustic evaluation of mycological biopolymer, an all-natural closed cell foam alternative. Industrial Crops and Products. 139:111533. https://doi.org/10.1016/j.indcrop.2019.111533.
Delhom, C.D., Indest, M.O., Wanjura, J.D., Armijo, C.B., Bowman, R.K., Faulkner, W.B., Holt, G.A., Pelletier, M.G. 2019. Effects of harvesting and ginning practices on Southern High Plains cotton: Textile quality. Textile Research Journal. 90(5-6):537-546. https://doi.org/10.1177/0040517519871942.
Pelletier, M.G., Holt, G.A., Wanjura, J.D. 2020. Cotton module feeder plastic contamination inspection system. AgriEngineering. 2:280-293. https://doi.org/10.3390/agriengineering2020018.
Sayeed, A., Schumann, M., Smith, W., Wanjura, J.D., Kelly, B., Hequet, E. 2020. Characterizing the total within-sample variation in cotton fiber length using the HVI fibrogram. Textile Research Journal. https://doi.org/10.1177/0040517520935212.
Pelletier, M.G., Holt, G.A., Wanjura, J.D. 2020. Plastic contamination image dataset for deep learning model development and training. AgriEngineering. 2(2):317-321. https://doi.org/10.3390/agriengineering2020021.