EFFECTS OF WATER STRESS AND PLANT DENSITY ON BOLL DISTRIBUTIONS AND BOLL YIELD COMPONENTS OF COTTON (Gossypium hirsutum L.) CULTIVARS DIFFERING IN MATURITY

摘要

Moisture deficit stress reduce lint yield by affecting yield and basic within-boll yield components. Field experiments were conducted in the Aegean region of Turkey during 2008 and 2009 to observe the responses of three cotton cultivars differing in maturity and seed size to deficit water stress under different plant densities. Deficit irrigation inversely affected boll distribution, yield components and within-boll yield components. It is interesting to note that yield components in this investigation differed greatly between M-2005 (late-maturing and large-seeded cultivar), and Carmen (late-maturing and smaller-seeded cultivar) and Flash (early-maturing and smaller-seeded). Non-significant irrigation x plant density for all investigated characters except for boll distribution showed that the response of cotton plant to water stress was determined by cotton genotype. Deficit irrigation inversely affected yield components and within-boll yield components. Deficit water stress decreased boll number located upper and distal positions; total seed surface area per m(2), and seed number per m2 for M-2005 more than Carmen and Flash. These results suggest late-maturing and also small-seeded cultivar would be preferable under deficit irrigation, and that cultivars with small seed are able to produce higher lint yield thorough the production of more bolls, seeds, and total seed surface area m(-2) than large-seeded cultivars.