Transfer of Pollen by Bees in Hybrid Cotton Seed Fields in Arizona

Gerald M. Loper, Gordon D. Waller, and Dick D. Davis


 
ABSTRACT

Experimental plantings (7-10 acres) of A- and B-line cottons (Gossypium hirsutum) were studied in three locations and of A-, B-, and R-lines in another location in Arizona in 1982. Various row ratio planting patterns were studied. Honey bee foraging densities and pollen dispersal measurements were made weekly. Yield estimates were obtained in all locations and pollination efficiency (stigma pollen counts/seeds per boll) relationships were determined. At Safford, AZ, the A-line and R-line (Pima, G. barbadense) were parents from Dr. Davis's NX-1 genetic system. When equally adapted CMS cotton (A-line) and B-line (commercial varieties) were used, lint yields on the CMS A-line ranged from about 50 to 83% of the adapted B-line. In Safford, the determinaret, early maturing A-line yielded only 50% of the B-line (DPL-90). However, at Aguila, the seed yield from the A line yielded 117% of the adapted Upland B-line cotton. At Safford, AZ, pollen deposition (grains/stigma) on the A-line adjacent to the Pima R-line averaged only 1/4 the pollen deposition on the A-line adjacent to the B-line. This is further evidence of what has earlier been referred to as the "'sticky' Pima pollen problem". In spite of this disparity, the A-line yields were equal; i.e., bee densities and pollen deposition was still high enough to facilitate complete pollination in this study. The results indicate that when the male parent is G. barbadense, been densities (as measured by % flower visitation) must be greater than what would be required for optimum pollination when a G. hirsutum is the male parent. Applications of various pesticides interfered with pollination at two locations resulting in inadequate pollen dispersal and yields.



Reprinted from Proceedings of the 1983 Beltwide Cotton Production Research Conference pg. 94
©National Cotton Council, Memphis TN

[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page
 
Document last modified Sunday, Dec 6 1998