Abstract
A field study was conducted to investigate the effects of field exposure and boll conformation upon fiber color properties for a broad spectrum of cotton genotypes. Sixty-eight genotypes were screened for intrinsic R (subscript d) and +b; 16 of these genotypes were selected for further evaluation. Ten agronomic and fiber property measurements were made on lint and seed from unopened, newly opened and field exposed bolls. A great amount of genotypic variability was shown for intrinsic fiber color (R (subscript d) and +b) and fiber color retention. Genotypes exhibiting higher initial R(subscript d) values showed a greater percent reduction with weathering, compared with genotypes showing lower initial R (subscript d) values. Three boll conformation groups (open-boll, storm-resistant and stormproof) were established and distinct fiber color properties were associated with each: open-boll types exhibited the largest R (subscript d) values and the largest percent reduction due to weathering while the smallest R (subscript d) values and smallest percent reduction resulting from weathering were associated with the stormproof genotypes. The lowest +b values and largest percent reduction from weathering were found for the open-boll genotypes. Stormproof genotypes exhibited the largest +b values and smallest percent reductions due to weathering. Decreasing +b reductions were associated with increasing exposure period when weathering was not aided with a sprinkler irrigation system. Chlorinated water was used in the sprinkler system as an aid to weathering and resulted in continually increasing +b reductions for increasing exposure periods. These reductions result possibly from bleaching, leaching or both..
Gannaway, John Robert (1973). The effects of field weathering on fiber color and certain agronomic and fiber properties of American upland cotton. Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -153903.