ARS | Publication request: Weed Species Density and Diversity in Roundup Ready Cotton: Perceptions Versus Reality

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: February 23, 2008
Publication Date: June 13, 2008
Citation: Cui, X., Rousselle, M.A., Rodgers III, J.E., French, A.D. 2008. Weed Species Density and Diversity in Roundup Ready Cotton: Perceptions Versus Reality. National Cotton Council Beltwide Cotton Conference. p. 1518-1520.

Interpretive Summary: Many cotton fiber properties are influenced by the moisture content. Therefore, cotton samples generally have to be conditioned under the standard atmosphere for sufficient time to achieve moisture equilibrium before testing, and most tests for cotton properties need to be performed under this standard condition also. Maintaining a well-controlled testing lab is costly and challenging, and this is especially true for developing countries. There has been interest to test cotton fibers in less strictly controlled or non-conditioned laboratories and to correct the test results by use of the sample moisture. The Uster HVI can be equipped with a sensor on the sample comb/clamp to measure the moisture of the specimen fiber beard. A set of cotton samples was tested for moisture content in Cotton Incorporated and Southern Regional Research Center on two HVIs that were equipped with moisture sensors. The cottons were also tested by oven method. The moisture contents from CI and SRRC tracked each other very well. However, the results showed a moisture level difference measured on the CI and SRRC’s HVI instruments. The sample moisture history and preparation methods also affected the sample moisture content even after 48 hours of conditioning. The HVI detected the change in sample moisture very well, which was also confirmed by the oven method.

Technical Abstract: A set of cotton samples was tested for moisture content in Cotton Incorporated and Southern Regional Research Center on two HVIs that were equipped with moisture sensors in the sample comb/clamps. The cottons were also tested by oven method. The moisture contents from CI and SRRC had a very high correlation coefficient (R=0.97). However, the results showed a moisture level difference measured on the CI and SRRC’s HVI instruments. All samples (from jars and vacuum-sealed bags) gained moisture after 48 hours of conditioning shown by both HVI and oven methods. Samples in the vacuum-sealed bags still had lower moisture content than that in the jars even after 48 hours of conditioning due to the moisture hysteresis. The HVI moisture measurement detected the change in sample moisture very well.