Responses of Winter Wheat to Herbicide-Fungicide Tankmixes

Tankmixing herbicides with fungicides could improve production efficiency and reduce application costs. A total of six field trials were conducted from 2012 to 2014 in Ontario to study the tolerance of winter wheat to herbicide (fenoxaprop-p-ethyl/mefenpyr, prosulfuron + bromoxynil and fluroxypyr + MCPA ester) plus fungicide tankmixes (pyraclostrobin/metconazole, tri-floxystrobin/propiconazole, azoxystrobin/propiconazole and picoxystrobin) applied alone and as a tankmix. At 1 WAT, fenoxaprop-p-ethyl/mefenpyr applied alone or in tankmix with tri-floxystrobin/propiconazole or azoxystrobin/propiconazole fungicides caused minimal visible injury (up to 1.3%) in winter wheat but caused no significant injury when applied as a tankmix with pyraclostrobin/metconazole or picoxystrobin fungicides. There was no effect on visible injury in winter wheat with other herbicide and fungicide tankmixes. Fenoxaprop-p-ethyl/mefenpyr applied alone with no fungicide reduced winter wheat height 3% but had no adverse effect on height when tankmixed with fungicides evaluated. Prosulfuron + bromoxynil or fluroxypyr + MCPA ester herbicides applied alone with no fungicide or tankmixed with pyraclostrobin/metconazole, tri-floxystrobin/propiconazole, azoxystrobin/propiconazole and picoxystrobin fungicides had no adverse effect on winter wheat height. There was no adverse effect of herbicide plus fungicide treatments on winter wheat yield. Co-application of fenoxaprop-p-ethyl/mefenpyr, prosulfuron + bromoxynil and fluroxypyr + MCPA ester herbicides with pyraclostrobin/metconazole, tri-floxystrobin/pro- piconazole, azoxystrobin/propiconazole and picoxystrobin fungicides could provide winter wheat growers with a single-pass treatment for the control of weeds and diseases.

氟磺隆水解动力学研究

采用试验室内模拟试验的方法,研究不同pH的缓冲溶液和不同自然水体对氟磺隆水解的影响。实验结果表明,不同pH缓冲溶液和不同自然水体对氟磺隆水解速率均有不同程度的影响。在碱性条件下氟磺隆的水解速率最快,半衰期为0.2 d,酸性条件下次之,半衰期为6.0 d,在中性条件下水解较慢,半衰期为15.7 d,而在不同自然水体中氟磺隆的降解速率为:伊通河水>稻田水>青湖水>蒸馏水。

超高效液相色谱-串联质谱法测定玉米和土壤中的氟磺隆

[目的]建立玉米和土壤中氟磺隆残留的液质串联快速分析检测方法。[方法]样品中的氟磺隆经乙腈提取，N-丙基乙二胺（PSA）和石墨化炭黑（GCB）净化，利用超高压液相色谱-串联质谱（uvLc—MS／MS）在多反应监测模式下进行检测。以碎片离子对418．2／252．1定性、离子对418．2／139．1进行外标法定量。[结果]仪器在O．005—1．0mg／kg范围内，具有良好线性关系。在0．005-0．5mg／kg添加水平范围内，氟磺隆在玉米和土壤中的平均回收率为84．8％-103．9％，变异系数为2．8％～7．5％。该方法的检出限（LOO）为0．031-0．034μg／kg，定量限（LOQ）为5μg／kg。[结论]方法简便、快速、准确，能满足国内外法规的要求，可用于玉米和土壤样品中氟磺隆的农药残留确证检测。