Cotton Lint Quality Protection Potential of Tighter Boll Types

ABSTRACT GRADES of cotton (Gossypium hirsutum L.) lint are lowered from color deterioration, dust and foreign matter contamination by exposure of open cotton bolls to adverse weather while waiting for harvest and by present harvesting methods. Modern ginning techniques can only partially maintain original grade potentials by dispersing the off color spots and partially removing foreign matter contamination. One possible solution to grade loss is to develop a more protective boll-type in cotton cultivars. The effect of a highly protective boll type was simulated by harvesting mature unopened bolls, removing the trash, leaf, and bracts before these bolls opened and by comparing a primitive strain of semi-closed boll cotton to standard machine-stripped varieties. Results showed that contamination of the seedcotton was practically eliminated by the experimental unopened boll procedure. Some bur particles remained in the ginned lint. Grade, lint brightness and degree of yellowness of the unopened boll and semi-closed boll cotton were preserved at a higher level than that of comparable machine-stripped cotton. Fine dust was reduced in the unopened boll cotton by as much as one-half of that found in comparable machine-stripped cotton.