A new method to calculate cotton fiber length uniformity using the HVI fibrogram

Authors: SAYEED, MD ABU - Texas Tech University; TURNER, CHRISTOPHER - Texas Tech University; KELLY, BRENDAN - Texas Tech University; Wanjura, John; SMITH, WAYNE - Texas A&M University; SCHUMANN, MITCHELL - Texas A&M University; HEQUET, ERIC - Texas Tech University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2023
Publication Date: 5/9/2023
Citation: Sayeed, M., Turner, C., Kelly, B., Wanjura, J.D., Smith, W., Schumann, M., Hequet, E. 2023. A new method to calculate cotton fiber length uniformity using the HVI fibrogram. Agronomy Journal. 13(5). https://doi.org/10.3390/agronomy13051326.
DOI: https://doi.org/10.3390/agronomy13051326

Interpretive Summary: The measurement of cotton fiber length characteristics is critical to cotton producers, ginners, and spinning mills in efforts to maximize economic returns and processing efficiencies. The variation in fiber length in cotton samples plays a large roll in determining how the material can be spun into yarn and the final quality of that yarn. The current way this length variation is described is through a parameter named length uniformity index (UI). UI does not adequately characterize the variability due to the shortest half of fibers in a cotton sample. Thus, this work was undertaken to develop an improved parameter for describing length variability. The new parameter was tested with cotton samples from research plots and from commercial bales and was shown to significantly improve yarn quality prediction models over the current UI parameter. Moreover, the benefits of this new parameter can be realized through use of existing fiber testing equipment with only moderate changes to the control software to process the required data.

Technical Abstract: Knowledge of cotton fiber length uniformity is important for the cotton industry. Accurate and reliable measurement of fiber length uniformity would allow cotton breeders to develop germplasm with improved within-sample variation in length. This knowledge would also help spinning mills to optimize their machine setup, which would improve yarn processing performance. Currently, High Volume Instrument (HVI) is most commonly used to characterize the within-sample variation in fiber length. HVI length measurement is based on the fibrogram principle Currently, HVI length measurement characterizes two points, 1.8% as upper half mean length (UHML) and 7.8% span length as mean length (ML), from the fibrogram and reports UHML and uniformity index (UI). UI is calculated as the ratio of ML to the UHML, expressed as a percentage. UI measurement does not represent the shorter fibers within a sample as the above two span length represents only the longest fibers within a sample. We propose to calculate the uniformity of cotton fiber length using the complete fibrogram as an alternative. First, the area of the measured fibrogram curve is calculated. Second, the area of a theoretical mono-length fibrogram with a length equal to the maximum length of the fibers for the same sample is calculated. Finally, we calculate a new length uniformity as the ratio of the measured fibrogram area to the mono-length fibrogram area expressed as a percentage. Based on the results obtained using a set of 991 commercial samples, the new length uniformity shows promise. We also applied this new length uniformity to a set of 60 commercial-like samples and developed partial least square regression (PLSR) prediction models to predict yarn quality. The results obtained demonstrate that the new length uniformity predicts yarn quality better than the current UI.