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ARS Home » Southeast Area » Stoneville, Mississippi » Cotton Ginning Research » Research » Research Project #439104

Research Project: Evaluation of the Impact of the Cotton Gin on Contaminating Cotton with Seed Coat Fragments and Plastic Module Wrap

Location: Cotton Ginning Research

Project Number: 6066-41440-009-006-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 28, 2020
End Date: Sep 27, 2022

Develop an understanding of the role of a cotton gin in contaminating ginned lint with seed coat fragments and plastic from round module covers. The propensity for seed coat fragments to be generated is a function of variety, production environment, and ginning conditions. The cotton gin is identified, by the industry, as responsible for the properties of ginned lint and thus developing a model for the cause of seed coat fragments will allow for the role of the gin to be isolated from other factors. Similarly, the gin is responsible for unwrapping modules, however if modules are damaged during harvesting, staging in the field, or transportation to the gin the job of separating seed cotton from plastic wrap is made more difficult. Determining the role of the contribution of the gin in contaminating ginned lint with plastic, due to handling of modules of seed cotton, will allow for the creation of practices and procedures for use by harvesters, transporters, and ginners that are tailored to their specific roles in preventing contamination. This is especially relevant with the introduction of cheaper and more inferior quality module, recently released into the marketplace. The developed best practices will result in reduced incidents of plastic contamination of ginned lint.

The Australian cotton industry will be used as an analog for the U.S. cotton industry. Although the U.S. industry is composed of over 500 gins with an average ginning rate of 40 bales per hour, new gins are moving towards higher capacity and higher ginning rates which are identical to the standard Australian gin that produce 60-100 bales per hour with identical make and models of equipment as found in the U.S. The Australian cotton industry spans from northern production regions which are similar to the southern U.S. regions and more temperate production regions in the central and southern regions of Australia which are similar to the largest cotton producing regions of the U.S. The Australian industry utilizes only six commercial varieties which are grown in all of the production regions, unlike the U.S. which has dozens of varieties tailored for each production region. Ginned seed and lint, of known variety, will be collected from multiple gins in each Australian cotton production region. Seed will be examined for size and damage while the lint will be assessed for seed coat fragments. Additionally, merchants will be surveyed for seed coat complaints from textile mills for bales from each production region. The limited varieties in use will allow for easy control of varietal influence while allowing the influence of growing region on seed quality to be studied. Differences in seed damage will be attributable to variety or growing condition because of the consistency in ginning conditions across the sampling locations. Weather data will be gathered and used in the model. The plastic contamination portion of the work will be carried out by surveying the condition of modules as they arrive at the gin and staged in the gin yard. The U.S. cotton industry is rapidly adopting round modules with over 50% of the industry having converted. The Australian industry is over 97% round modules and, like the U.S., has adopted numerous methods for separating the plastic module wrap from the seed cotton. Incidents of plastic contamination in ginned lint will be matched to the gin handling methodology. Models for both seed coat fragment and plastic contamination will be developed based on ginning systems. Furthering the understanding of the gin’s role in contamination will allow for gins to adopt practices which reduce contamination and improve the quality of ginned lint.