SCREENING HERBICIDE COMBINATIONS FOR EFFECTIVE NAVUA SEDGE MANAGEMENT IN THE HERBERT CANE GROWING REGION

摘要

navua sedge (Cyperus aromaticas) is a clump-forming perennial sedge that can be spread by seeds or from rhizomes. It has been reported on roadsides in the Mulgrave district in the late 1980s and is now found from Mossman to the Herbert.It has become established in cane blocks in the wetter areas of districts and can stall basecutters while mechanical harvesting.A replicated field trial was established in ratoon cane during the 2011/12 wet season. A range of herbicides and tank mixtures was applied to established navua sedge (approximately 15-100 cm tall) in a third ratoon block of Q204, which was between 75-125cm tall at the time. Li 700~R @ 250 mL per 100 L of spray volume was added as the adjuvant.Sempra~R @ 130 g/ha and Hero~R @ 250 g/ha treatments as well as Hero~R @ 250 g/ha plus Actril~R DS @ 1.5 L/ha all gave a complete kill of small clumps of navua sedge. However, even though the ratings improved over time for the larger clumps of navua sedge, later inspections revealed regrowth and a second application would have been required for satisfactory control.All treatments that included Krismat~R achieved excellent control of smaller clumps and seedlings less than 15-20 cm tall as well as acceptable control of even taller clumps. The addition of Daconate~R improved the initial knockdown as well as the overall performance of Krismat~R. Daconate~R @ 3 L/ha plus Actril DS @ 1.5 L/ha or Velpar~R K~TM @ 2 L/ha plus Daconate~R @ 3 L/ha gave acceptable control of all size clumps of navua sedgeNavua can be effectively controlled in fallow situations with a blanket application of herbicides. Management in ratoon cane can be achieved with a directed application of herbicides under the crop canopy, as required.