Effects of Harvest-Aid Herbicides on Sicklepod (Cassia obtusifolia) Seed Yield and Quality

Abstract

Experiments were conducted in 1989 and 1990 to study the effects of 220 g ai ha-1AC 263,222, 840 g ai ha-1glufosinate, 560 g ai ha-1glyphosate, and 840 g ai ha-1paraquat on sicklepod seed production and quality when applied at R5, R6, R7, and R8 growth stages of sicklepod. No seed were produced on plants treated at R5 with paraquat and glufosinate; glyphosate was the least effective herbicide at this growth stage. Although sicklepod seed germinated after AC 263,222 application at R5, no seedling emergence occurred. Normal seedlings, seedling emergence, and seedling radicle length were reduced by all herbicides applied to parent plants at R5, R6, and R7 growth stages. AC 263,222 applied at R7 reduced normal seedlings and seedling emergence more than any other herbicide. No effects were observed on any of the variables investigated when herbicides were applied at R8.