Field studies were conducted during the years 2000 to 2003 at Stoneville, MS, to determine the efficacy of fall deep tillage and glyphosate applications on redvine and trumpetcreeper populations and soybean yield in glyphosate-resistant soybean. Fall deep (≈45 cm) tillage for 1, 2, and 3 yr reduced redvine density by 95, 88, and 97%, respectively, compared with shallow (≈15 cm) tillage, but deep tillage did not reduce trumpetcreeper density. Glyphosate applied preplant reduced trumpetcreeper density (25 to 44%), but not redvine density, compared to that with no glyphosate. Glyphosate early postemergence (EPOST) either alone (45 to 67%) or followed by (fb) late postemergence (LPOST; 59 to 83%) reduced density of trumpetcreeper, but not of redvine, compared to that with no herbicide. However, dry biomass of both vines was reduced with glyphosate EPOST or LPOST compared to that with no herbicide. Soybean yields were higher with deep tillage vs. shallow tillage, glyphosate preplant application vs. no glyphosate, and glyphosate EPOST either alone or fb LPOST vs. no herbicide. Redvine did not reestablish in 2003, which was after skipping fall deep tillage for 1 yr following three consecutive years of deep tillage compared with shallow tillage. It is possible to manage redvine infestations with fall deep tillage and trumpetcreeper infestations with glyphosate preplant and postemergence (POST) in-crop applications. Integration of fall deep tillage and glyphosate POST applications could be an effective strategy to manage combined infestations of these vines in glyphosate-resistant soybean.
Nomenclature: Glyphosate; redvine, Brunnichia ovata (Walt.) Shinners #3 BRVCI; trumpetcreeper, Campsis radicans (L.) Seem. ex Bureau # CMIRA; soybean, Glycine max (L.) Merr. ‘DP4690 RR’, ‘DP 5806 RR’, ‘AG 4702 RR’.
Additional index words: Deep tillage, perennial vine, transgenic soybean, weed biomass, weed density.
Abbreviations: EPOST, early postemergence; fb, followed by; LPOST, late postemergence; POST, postemergence; WAP, weeks after planting soybean; WAT, weeks after late postemergence.