Herbicide efficacy in retained stubble systems

The GRDC project ‘Maintaining profitable farming systems with retained stubble - upper Eyre Peninsula’ aims to improve farm profitability while retaining stubble in farming systems on upper Eyre Peninsula (EP). Weed control in stubble retained systems can be compromised when stubbles and organic residues intercept the herbicide and prevent it from reaching the desired target, or the herbicide is tightly bound to organic matter. Reduced herbicide efficacy in the presence of higher stubble loads is a particular issue for pre-emergence herbicides. Current farming practices have also changed weed behavior with a shift in dormancy in barley grass genotypes now confirmed in many paddocks on Minnipa Agricultural Centre (MAC) (B Fleet, EPFS Summary 2011, p 177). As a part of the stubble project this trial was undertaken to assess herbicide efficacy in different stubble management systems.

谷物研究与开发公司（Grains Research and Development Corporation，GRDC）资助的“艾尔半岛上部保留秸秆维持盈利耕作系统”项目，旨在优化艾尔半岛（Eyre Peninsula，EP）地区采用秸秆保留模式的耕作系统，提升农场经营收益。在秸秆保留耕作系统中，秸秆与有机残渣可能会拦截除草剂，使其无法抵达靶标位点；或使除草剂与有机质紧密结合，进而削弱杂草防控效果。当秸秆覆盖量较高时，除草剂药效下降的问题在芽前除草剂领域尤为突出。当前耕作模式亦改变了杂草的生存特性，目前已在明尼帕农业中心（Minnipa Agricultural Centre，MAC）的多个试验田内确认，大麦草基因型的休眠特性已发生偏移（B Fleet，《EPFS总结2011》，第177页）。作为该秸秆项目的组成部分，本试验旨在评估不同秸秆管理模式下的除草剂药效。