Texas, USA 2010 - International Herbage Seed Group

Table xx. Herbicide treatments and efficacy on V. myuros in a winter wheat field experiment. Meansfollowed by the same letter do not significantly differ.In winter wheatAfter harvest of winter wheatRed fescue 200920072008WinterSpringDate 08.10 31.10 19.08 14.08 02.09 27.10 02.01 20.05TimingABCDETreatment% control% control% control1 Stomp +AtlantisWG- 83 a Stomp Stomp 91 ab Reglone 58 a2 Stomp AtlantisWG96 a Stomp Stomp 92 ab Reglone 55 a3 Stomp - 32 b Stomp Stomp 73 bc Reglone 34 b4 - - - Stomp Stomp 66 c Reglone 38 b5 Reglone 24 cIn spring cereals the efficacy of Stomp was only 5%. Combinations of Stomp and Atlantis WGgave 73% effect when applied in a tank mix at timing A, and similar to the winter wheatexperiment the efficacy was improved (to 87%) when Stomp was applied at timing A andAtlantis WG at timing B. The visual assessments in October reflecting the efficacy of sprayingsin the spring barley as well as after harvest of the cereal crop (A, B, C and D), showed a highefficacy (94-96%) of treatments 1 and 2 and a low efficacy (40-44%) of treatments with only oneor no Stomp application in the cereal crop (treatments 3 and 4). Reglone applied in January had alow effect on V. myuros while Kerb had a high effect. The ground cover of V. myuros in Maywas 1-2% for all treatments including Kerb but 3-11% for all treatments including Reglone.Atlantis WG is not registered for use in spring barley and caused severe crop damage by foliageyellowing and plant stunting. Growth reduction in red fescue after the C and D applications ofStomp was 3% for treatments 3 and 4 and 7-8% for treatments 1 to 4. Red fescue coverage inMay in the seed harvest year was 84-90% for all treatments that had Reglone and 31 to 43% forall treatments with Kerb in the winter.Perspectives139