Gram-Negative Bacterial Content and Fiber Properties of Raw Cotton

Abstract

The content of gram-negative bacteria was determined for 109 samples of the 1978 crop of American upland raw cotton derived from seven grade divisions and five visual color groups. The populations of gram-negative bacteria entrained in these raw cottons varied from 1.5 X 1010 to 1.5 X 1014 for standard bale size (217.7 kg) lots. Raw cotton fiber parameters, including upper-half-mean length, length uniformity, strength, micronaire, maturity, and fineness, were all significantly and inversely correlated with the content of entrained gram-negative bacteria. The yellowness of raw cottons as measured by the cotton colorimeter was significantly and positively correlated with bacterial content. About half of the variability of gram-negative bacterial content in raw cotton samples of the 1978 American upland crop can be accounted for by variation in micronaire ( r2 = 0.504).