|
Eighteen plant characteristics and growth ratings were examined for their effect of five lint yield and quality measurements obtained from a set of seventy-nine diverse strains of striper harvested cotton. Factor analysis was used to look for the independent physical elements within the variation of the entire data set. Bivariate and stepwise regression analyses were used to identify linear relationships of plant and growth characters of plant and growth characters with yield and quality measurements. Six independent elements (Factors) were identified which explained 72 percent of the total variance in the data. Plant hairiness emerged as the most distinct element in this data. The number of teeth per bract was also slightly related to this element. Variables having to do with plant growth separated into another independent element. Size of the plant and its parts was negatively correlated with ratings for maturity and incidence of verticillium wilt. Lint yield had a slight correlation with this plant growth element. Seed size, lint length, seed cotton per boll, and fiber strength separated into an element that seem to be a product size relationship. The number of seeds per boll, peduncle strength, peduncle diameter, and weight of lint per seed separated as an element that is a contrast related to the partitioning of dry matter between lint and the other elements making up the boll. Lock tenacity and angle of boll opening, in combination with linters content of the seeds, separated as a separate element that apparently represents boll tightness. Lint yield and fiber strength had small correlations with this element. Lint uniformity and micronaire separated as an element that possibly represents lint maturity. Lint yield would not separate as a distinct element nor clearly load onto one of the distinct elements that emerged. This means that lint yield is a complex function of the other variables and not simply correlated with any one. Grade index was represented by only four grades across all 79 cotton strains and had no definite correlation with any of the genetic factors measured. Fiber length tended to be positively correlated with seed size and fiber strength by deviations around the trends were large. Span length measured on field samples was fairly well correlated with upper half mean and classers staple of the ginned lint, having correlation coefficients of 0.89 and 0.73 with each one respectively. There were also low correlations (0.42, 0.34) between boll size and the fiber length measurements. Micronaire was not associated with the other variables except for a weak negative correlation (-0.46) with span length of field samples. Brightness % reflectance of the lint tended to be negatively correlated with foreign matter (-0.44) and stick content (-0.47) of the machine stripped cotton and positively correlated (0.50) with lock tenacity. Brightness was correlated with yield (0.64) and several other variables, consequently it was dropped out of the factor analysis to get a more clearly interpretable result. Yellowness or colorimeter +b was weakly correlated with maturity rating and micronaire, having correlation coefficients of -0.52 and 0.42 respectively. |
|
|
©National Cotton Council, Memphis TN |
Document last modified Sunday, Dec 6 1998
|