An investigation was started in 1987-88 to update lint-cleaner recommendations for spindle-harvested cotton in view of changing varieties and grading standards, and recent lint-cleaner developments. Most of the research data used to formulate present recommendations were collected 20 years ago. Specifically the effect of non, one, two, and three stags of saw-cylinder lint cleaning upon classer's grade and staple length, and weight and market value of the bale was studied. Both smooth- and hairy-leaf varieties are included in the study.

Increasing the number of lint cleaners gave a consistent improvement in the grade index of the cleaned lint, but caused the bale weight to decrease with each cleaner used. Wasted material extracted per bale by one, two, and three lint cleaners averaged 32, 42, and 53 percent. Neps in the ginned lint increased from 11 to 32 neps per 100 in 2 of web with lint cleaning and the increase at each of the three stages was statistically significant. Seed-coat fragments averaged about 50 fragments/3g lint and the count was only slightly affected by lint cleaning.

The use of too many stages of lint cleaning, reduced the bale value, because the weight loss offset any gain from grade improvement. Smooth-leaf variety cottons generally required one less lint cleaner than hairy-leaf varieties used in the experiments. No lint cleaning produced the highest bale value on one smooth-leaf variety; while one or two lint cleaners gave the highest dollar value with a second smooth-leaf cotton. The same general trend in bale values was obtained when using the 1987 CCC loan values. Experiments will continue on this project to increase the data base. Lint cleaners built by the various manufacturers will be used.