Peanut Yield and Injury from Thrips with Combinations of Acephate, Bradyrhizobium Inoculant, and Prothioconazole Applied in the Seed Furrow at Planting

Abstract

Core Ideas Acephate and prothioconazole did not adversely impact peanut response to Bradyrhizobium inoculant. Peanut was more responsive to Bradyrhizobium inoculant when planted in fields with no history of peanut production than in fields with recent peanut plantings. Acephate, Bradyrhizobium inoculant, and prothioconazole can be applied simultaneously in the seed furrow without losing effectiveness of individual components. Peanut (Arachis hypogaea L.) growers often apply commercial inoculant in the form of Bradyrhizobium to the seed furrow at planting to promote biological nitrogen fixation. Additionally, disease and injury from thrips (Frankliniella spp.) feeding can be reduced when prothioconazole and acephate, respectively, are applied in the seed furrow. Interactions of these products have not been determined for Virginia market‐type peanut. Six experiments were conducted during 2009 and 2010 to define interactions of acephate, Bradyrhizobium inoculant, and prothioconazole when co‐applied in the seed furrow at planting. Acephate and prothioconazole did not affect peanut yield response to Bradyrhizobium inoculant. Peanut yield increased in two of six experiments when Bradyrhizobium inoculant was applied. The increase in yield was observed in fields that did not have a known history of peanut production. Visible thrips damage was lower when prothioconazole was applied in absence of acephate, although acephate was more effective in minimizing injury from thrips than prothioconazole. Although acephate did not affect peanut yield, prothioconazole increased yield in all experiments regardless of acephate or Bradyrhizobium treatment. Results from these experiments indicate that acephate, inoculant containing Bradyrhizobium, and prothioconazole are compatible in peanut production systems.