188宝金博页面版

341Thirteenth Australian W eeds Conf erenceSummary Four trials conducted at two sites during 2001, using Select® showed the effect that environ-mental and crop conditions can have on weed control, and gave some indication of adjuvants that might be useful in dealing with application in less than perfect conditions.Keywords Clethodim, Select, sulphate, adjuvants, annual ryegrass.atrazine, ammonium INTRODUCTIONThis paper reports a series of four trials carried out in Western Australia during 2001. Clethodim, sold under the trade name of Select®, is a major herbicide in the post-emergent annual ryegrass control market in Australia. Atrazine forms the basis of weed control programs in Triazine Tolerant Canola crops. In spite of timing confl icts between Select and atrazine application, there are occasions when the two products are tank mixed. There have also been instances when these mixtures have failed to provide adequate weed control, while split applications have been effective. There were two primary objectives for the trials; (a) to examine the adjuvants used in combination with Select, and identify possible ways to improve the adjuvant system used with the product, and (b) to examine the adjuvants recommended for use with Select and atrazine tank mixtures, again with the aim of improving the effi cacy of those mixtures.The targeted weeds were populations of annual ryegrass ( Lolium rigidum), which were suspected to be resistant to the ‘fop’ herbicides.MATERIALS AND METHODSAll trials were established with four replicates. One site was at Piawaning (Site 1) in the Western Australian wheat belt, while the second site was at Bindi Bindi (Site 2). There were two trial protocols used, one incor-porating atrazine mixtures, and one focused on Select in combination with various adjuvants. The strategy behind the trial protocols was to de-liberately use lower rates than normal of Select, as a means of identifying differences between the perform-ance of the adjuvants tested. Seasonal conditions in 2001 also had a signifi cant impact on the trials.Both plans were repeated at the two sites. Site 1 had very poor growing conditions prior to application, whereas Site 2 had good growing conditions prior to application.All treatments were applied using a wheelbarrow mounted boom spray, operating at 200 kPa pressure, through Tee Jet 11001 nozzles at 3.6 km h-1. This pro-vided a total water volume of 107 L ha-1.The atrazine formulation used was a 500 g L-1 fl owable. LiaseTM is a liquid formulation of ammonium sulphate. HastenTM, UptakeTM, EnhanceTM, FreewayTM and Hot-upTM are all commercially available adjuvants from various manufacturers.Adjuvants for use with Select herbicide and mixtures with atrazine David Howey1 and Mark Sumner21 Sumitomo Chemical Australia Pty. Ltd., PO Box 3023, Mandurah East, Western Australia 6210, Australia2 Serve-Ag Research, 14 Elizabeth Street, South Perth, Western Australia 6151, AustraliaTable 1. Adjuvants used with Select for control of annual ryegrass (2001).ProductsRatesSite 1 – Piawaning (50 DAT)Site 2 – Bindi Bindi (51 DAT)Annual ryegrass count m-2% control Annual ryegrass count m-2% control Untreated77.50–207.2–Select + Hasten200 mL + 1.0%44.2542.97.296.5Select + Uptake200 mL + 0.5%29.7535.87.896.3Select + Uptake200 mL + 1.0%34.5055.54.298.0Select + Enhance200 mL + 1.0%38.7550.05.097.6Select + Hot-up200 mL + 0.25%58.0025.219.590.6Select + Freeway200 mL + 0.02%58.5024.581.061.9Select + Hasten + Liase 200 mL + 1% + 2%40.2548.14.797.8LSD 95%32.35737.983