Effects of Flower Bud Removal and Nitrogen Supply on Growth and Development of Cotton (Gossypium hirsutum L.)

Abstract

Effects of flower bud removal for various durations (20 or 90 days following first flower bud appearance or 35 days following first flower opening) and nitrogen supply (non-limiting and 33 % of the nitrogen uptake of non-limited plants) on growth characteristics of glasshouse-grown cotton plants are reported. Removal of flower buds and high nitrogen supply stimulated elongation of the main stem and the number of fruiting positions per plant. Nitrogen supply increased both main stem node number and mean internode length whereas flower bud removal increased only the number of nodes on the main stem.

Flower bud removal did not reduce total dry matter yields, number of flowers produced or number of bolls. Vegetative organs provided efficient storage for excess assimilates resulting from the complete suppression of fruiting activity. Plants subjected to nitrogen stress had lower dry matter yield, number of flowers and number of bolls. Compensation following flower bud removal was greater at higher than at lower nitrogen supply. Relative fruitfulness, the partition of biomass between vegetative and reproductive organs, was not affected by either flower bud removal or nitrogen supply.