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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #400305
Research Project: Development of Novel Cottonseed Products and Processes

Location: Commodity Utilization Research

Title: Seed hull fracture resistance of Upland and Pima cotton cultivars

Author
item DOWD, MICHAEL - Collaborator
item Delhom, Christopher - Chris

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2023
Publication Date: 7/1/2023
Citation: Dowd, M.K., Delhom, C.D. 2023. Seed hull fracture resistance of Upland and Pima cotton cultivars. Journal of Cotton Science. 27(3):120-126. https://doi.org/10.56454/DVVH5560.
DOI: https://doi.org/10.56454/DVVH5560

Interpretive Summary: This work describes experiments to compare the seed hardness of the two major species of cotton planted in the United States. Early literature indicated that Pima cottonseed was weaker than Upland cottonseed. This conclusion, however, was based on a very limited dataset and likely on seed tested in uncontrolled conditions, which we know now is important to get consistent strength values. In this report, several Pima and Upland cultivars were tested for the amount of force needed to crack the seed, and the results indicate that generally it is the Pima seed that is more difficult to crack than the Upland seed. The results will be of some interest to the ginning industry given the current problem of weak seed being damaged during the ginning process resulting in low quality scores.

Technical Abstract: Seed durability is a current issue of cotton ginners, who have noted smaller and weaker seed, lower seed grades, and increased seed coat fragments within ginned cotton fiber. To better understand the differences in the seed hull properties of Upland (Gossypium hirsutum L.) and Pima (G. barbadense L) seed, compression testing was conducted to determine the seed hull fracture resistance of both species. Plants were grown in Five Points, California, USA, for two years. After roller ginning, seeds were conditioned to a standard set of environmental conditions and were compressed until rupture on a material strength tester. Generally, the seeds of the Pima cultivars required significantly greater maximum compressive force and energy to rupture than did the seeds of the Upland cultivars. However, when the seeds were compressed in a vertical orientation, a few individual Upland cultivars did have compression properties within the range of values observed for the Pima cultivars. Hence, it is possible to find Upland seed with compression properties comparable to or slightly greater than those of some Pima seed. Differences in the data for the two years showed that growing environment affects seed hull strength properties. The results should help clarify some conflicting literature regarding the relative strength attributes of Gossypium species seed.