Abstract: The present invention relates to a cotton plant, seed, variety and hybrid. More specifically, the invention relates to a cotton plant having a mutant allele designated OA1 which results in a cotton plant with a Main Stem Load structure when present in either the heterozygous or homozygous state. The invention also relates to crossing cotton plants containing the OA1 mutant allele with cotton plants lacking the OA1 mutant allele to produce novel types of cotton plants.

Abstract: Cotton plants may be rendered male sterile while retaining substantial female fertility by contracting the plants with a gametocidally effective amount of a novel compound which has the formula: ##STR1## where X is oxygen, sulfur, or ##STR2## and where R is a substituted and unsubstituted aryl, alkyl, cycloalkyl, alkoxy and alkene group, and maintaining the effective amount for a sufficient time to form sterile plant flowers that can then be pollinated by a second variety cotton plant to provide cotton having hybrid cotton seeds.

Abstract: Methods are disclosed for rendering cotton plants male sterile through application of isothiazole plant growth regulators without causing substantial female sterility or loss of reproductive vigor. Processes for effecting the hybridization of cotton employing monitoring of the degree of burning of cotton bracts are presented. More particularly, male sterility is attained by the application of potassium 3,4-dichloroisothiazole-5-carboxylate to cotton plants in an amount sufficient to cause finger burning of the bracts without causing excess burning thereof. Hybridization is attained by exposing male sterile plants in accordance with the foregoing processes to pollen from plants of differing varieties of cotton.

Abstract: Methods are disclosed for rendering cotton plants male sterile through application of isothiazole plant growth regulators without causing substantial female sterility or loss of reproductive vigor. Processes for effecting the hybridization of cotton employing monitoring of the degree of burning of cotton bracts are presented. More particularly, male sterility is attained by the application of potassium 3,4-dichloroisothiazole-5-carboxylate to cotton plants in an amount sufficient to cause finger burning of the bracts without causing excess burning thereof. Hybridization is attained by exposing male sterile plants in accordance with the foregoing processes to pollen from plants of differing varieties of cotton.