Application of near infrared spectroscopy in cotton fiber micronaire measurement

The term “micronaire” describes an important cotton fiber property by characterizing both the fiber maturity and fineness. In practice, micronaire is regularly measured in laboratories with the well established high volume instrumentation (HVI™) protocol. In most scenarios, cotton breeders/geneticists sent cotton breeding line field trial samples to laboratories equipped to use the HVI™ systems available for fiber micronaire determination. Researchers have previously investigated the use of NIR as an alternative means of measuring micronaire either at breeding sites or in standard laboratories. As a proof-of-concept investigation, this study collected both near infrared (NIR) spectra and HVI™ micronaire from a total of 381 cottons harvested in the 2011 and 2012 crop years. Partial least square (PLS) calibration model relating NIR spectral information to fiber HVI™ micronaire was developed and then applied to both a validation sample set from identical crop years and an independent test sample set from the 2014 crop year. Results indicated an acceptable bias (or differences between HVI™ measured and NIR predicted micronaire) and an over 97% correctly predicted micronaire (within ±0.30 micronaire unit) in an independent test set. Therefore, the development of a robust and effective NIR model for rapid laboratory micronaire assessment that would be applicable to remote/breeding locations is feasible.