Influence of Harvest-Aid Herbicides on Dry Bean (Phaseolus vulgaris) Desiccation, Seed Yield, and Quality1

Abstract

Field trials were conducted in 1998 and 1999 to determine the influence of harvest-aids on dry bean desiccation, seed yield, and quality. Light Red Kidney and Great Northern dry beans were pulled from the soil and placed on the soil surface to dry or treated with glufosinate at 440 g ai/ha, with glyphosate at 840 g ae/ha, or with paraquat at 560 g ai/ha at three stages during the maturation process. Dry bean seed weight and seed yield were reduced by all harvest-aid treatments applied when only 5 to 7% of the seedpods were yellow. Herbicides did not affect dry bean seed yield, weight, or germination if treatments were delayed until 77 to 85% of the seedpods had turned yellow. Application of harvest-aids at early stages of the maturation process enhanced desiccation of dry bean plants, pods, and seeds, but reduced yield. Herbicides applied at later stages of the maturation process avoided seed yield reductions, but were not as effective in desiccating plants. Therefore, applying glufosinate, glyphosate, or paraquat to reduce the time from dry bean maturation to harvest may not be beneficial when the crop is grown on the high plains of the United States.Nomenclature: Glufosinate; glyphosate; paraquat; dry bean, Phaseolus vulgaris L.Additional index words: Great Northern ‘Beryl’, Light Red Kidney ‘Sacramento’.Abbreviations: DAT, days after treatment.