Physiological analysis of yielding ability in Hirsutum cottons II. Parameters controlling dry matter accumulation, boll number and seed-cotton yield

Nine varieties of hirsutum cotton, differing in their growth habits, dry matter production and seed-cotton yield, were examined for the components of seed-cotton yield and dry matter accumulation. Seed-cotton yield is controlled by boll number as well as dry matter produced. The effect of boll number is a direct one, while the dry matter effects yield through boll number. Boll number and boll weight contributed over 95% seed-cotton yield, though individually the correlation between boll weight and seed-cotton yield was not significant. Boll number and fruiting points produced were associated with dry matter production, while the boll weight showed its association with fruiting coefficient and the efficiency of the plant to transfer dry matter to the reproductive parts during flowering. A negative correlation was observed between boll number and boll weight and between dry matter and fruiting coefficient. Dry matter production was related mainly with mean leaf area of the plant. It is, therefore, suggested that for achieving higher seed cotton yield, an optimum balance between dry matter and fruiting coefficient is necessary.