Use of Heat Tolerance in Cotton Breeding

Carl V. Feaster and E.L. Turcotte


 
ABSTRACT

Much of the Pima cotton (Gossypium barbadense L.) production in Arizona is at low elevation below 450 m) where day and night temperatures are high, 430C+ and 27 C+, respectively, during the fruiting period. In this environment, the adaptation of a cultivar depends largely on its tolerance to high night temperatures. Boll shedding commonly is severe in cultivars without heat tolerance. Breeding for heat tolerance has been a major objective of the Pima improvement program since the late 1950's.We have used the height on the plant at which an appreciable number of bolls begin setting as an indicator of heat tolerance. Bolls setting at a lower level on the plant indicates greater heat tolerance. The releases of 'Pima S-21 in 1960, 'Pima S-4' in 1966, and 'Pima S-5' in 1975, each with progressively increased heat tolerance, have resulted in over a 50 percent increase in commercial Pima yields at low elevation in Arizona. The release of 'Pima S-61 in 1985 likely will provide further gains in commercial Pima fields.



Reprinted from 1985 Proceedings: Beltwide Cotton Production Research Conferences pp. 364 - 366
©National Cotton Council, Memphis TN

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