Interactions of Late-Season Morningglory (Ipomoea spp.) Management Practices in Peanut (Arachis hypogaea)1

Abstract

Experiments were conducted in North Carolina during 2002 and 2003 to evaluate entireleaf morningglory control by 2,4-DB applied alone or with seven fungicides. In a separate group of experiments, tall morningglory control by 2,4-DB was evaluated when applied in four-way mixtures with the following: the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, or tebuconazole; the insecticide lambda-cyhalothrin; and the foliar fertilizer disodium octaborate or the plant growth regulator (PGR) prohexadione calcium plus urea ammonium nitrate. Pyraclostrobin, but not azoxystrobin, boscalid, chlorothalonil, fluazinam, propiconazole plus trifloxystrobin, or tebuconazole, reduced entireleaf morningglory control by 2,4-DB. Mixtures of fungicides, insecticides, and foliar fertilizer/ PGR did not affect tall morningglory control by 2,4-DB. Placing artificial morningglory in the peanut canopy when fungicides were applied did not intercept enough fungicide to increase peanut defoliation by early leaf spot and web blotch or reduce pod yield compared with fungicide applied without artificial morningglory.Nomenclature: 2,4-DB; azoxystrobin; boscalid; chlorothalonil; fluazinam; lambda-cyhalothrin; prohexadione calcium; propiconazole; pyraclostrobin; tebuconazole; trifloxystrobin; entireleaf morningglory, Ipomoea hederacaea var integriuscula Gray #3 IPOHG; tall morningglory, Ipomoea purpurea (L.) Roth # PHBPU; early leaf spot, Cercospora arachidicola S. Hori; web blotch, Phoma arachidicola (Marsas et al.); peanut, Arachis hypogaea L. ‘NC-V 11’, ‘VA 98R’.Additional index words: Fungicide deposition, pesticide interactions, weed interference.Abbreviations: PGR, plant growth regulator; UAN, urea ammonium nitrate.