丙炔氟草胺与二甲戊灵混配使用对棉田杂草的防除效果及棉花安全性研究

为明确丙炔氟草胺与二甲戊灵混配使用防除新疆覆膜棉田杂草的效果及其对棉花的安全性,在新疆南北疆进行了田间药效试验。结果表明,50%丙炔氟草胺WP 45~120 g/hm2+33%二甲戊灵EC 742.5/1 237.5 g/hm2对龙葵Solanum nigrum、藜Chenopodium album、灰绿藜C.glaucum、反枝苋Amaranthus retroflexus和稗草Echinochloa crus-galli等一年生杂草防除效果理想,持效期45～60 d,对苘麻Abutilon theophrasti、田旋花Convolvulus arvensis有一定的防效,但对其生长抑制作用不佳,对榆树Ulmus pumila 苗防效差。50%丙炔氟草胺WP+33%二甲戊灵EC高剂量处理或在持续低温多雨情况下,对棉花出苗和生长有一定影响。在农业生产中,应重视完善和优化丙炔氟草胺与二甲戊灵混配使用的田间应用技术,避免和降低除草剂药害风险。     

气相色谱/气质联用分析5种农产品中的苯醚甲环唑和丙炔氟草胺残留

采用乙酸乙酯提取、活性炭-酸性氧化铝复合柱净化、丙酮/正己烷(1/2,V/V)洗脱法,建立了苯醚甲环唑和丙炔氟草胺在5种农产品上的残留气相色谱-ECD分析法、气质联用确证法。采用气相色谱-ECD法分析时,苯醚甲环唑在生姜、敏豆、毛豆、甘蓝、辣椒的添加回收率为76.4%～101.1%,丙炔氟草胺在生姜、敏豆、毛豆、甘蓝、辣椒的添加回收率为78.7%～102.8%,方法的检测低限为0.001mg·kg-1。采用气质联用法分析时,苯醚甲环唑的SIM离子:325、323(Q)、267、265,丙炔氟草胺的SIM离子:355、354(Q)、287、259,方法的检测低限为0.005mg·kg-1。     

Hydrolysis and photolysis of flumioxazin in aqueous buffer solutions

To determine the degradation rates and degradation products of the herbicide flumioxazin in aqueous buffer solutions (pH 5, 7 and 9), its hydrolysis and photolysis were investigated at 30 degrees C in the dark, and in a growth chamber fitted with fluorescent lamps simulating the UV output of sunlight. The rate of hydrolysis of flumioxazin was accelerated by increasing pH. The t(1/2) values at pH 5, 7 and 9 were 16.4, 9.1 and 0.25 h, respectively. Two degradation products were detected and their structural assignments were made on the basis of LC-MS data. Degradation product I was detected in all buffer solutions while degradation product II was detected in acidic buffer only. Both degradation products appeared to be stable to further hydrolysis. After correcting for the effects of hydrolysis, the photolytic degradation rate also increased as a function of pH and was approximately 10 times higher at pH 7 than that at pH 5, showing t(1/2) values of 4.9 and 41.5 h, respectively. Degradation products formed by photolysis were the same as those formed by hydrolysis. Flumioxazin was degraded more extensively at high pH and should degrade in surface water.     

50%丙炔氟草胺可湿性粉剂防除夏大豆田杂草田间药效试验

田间试验结果表明,50%丙炔氟草胺可湿性粉剂8.0～12.0g/667m2,对大豆田阔叶杂草有较好的防除效果,并且有较长的持效期。对大豆生长安全。     

34%丙炔氟草胺·二甲戊灵乳油对棉田阔叶杂草的防除效果

【目的】研究丙炔氟草胺与二甲戊灵混配剂的除草作用及对棉花的安全性,为新疆棉田杂草防除系统提供新方案。【方法】以二甲戊灵为参比对照,通过田间药效试验方法测定丙炔氟草胺单剂、丙炔氟草胺·二甲戊灵混配剂对棉田杂草的控制作用,评价药剂对棉花的安全性。【结果】34%丙炔氟草胺·二甲戊灵乳油在剂量175~200 mL/667 m²下对3种杂草的效果均较好,与对照药剂42%丙炔氟草胺悬浮剂相比,无显著差异,与对照药剂33%二甲戊灵乳油相比,优于该药剂。【结论】丙炔氟草胺·二甲戊灵混配剂的阔叶杂草的防除效果优于二甲戊灵,对棉花安全,可在新疆地区进行推广使用。     

QuEChERS-高效液相色谱-串联质谱法测定丙炔氟草胺在食品和环境中的残留及土壤中的消解动态

建立了QuEChERS-高效液相色谱-串联质谱 (QuEChERS-HPLC-MS/MS) 测定丙炔氟草胺在食品 (苹果、葡萄、柑橘、甘蓝、小麦、大豆)、土壤和水中残留量的方法，并分析了其在土壤中的消解动态。样品经乙腈均质提取，采用C₁₈、N-丙基乙二胺 (PSA)、石墨化碳黑 (GCB) 和无水硫酸镁混合净化剂分散萃取处理，以C₁₈色谱柱分离，采用电喷雾正离子 (ESI+) 扫描，多反应监测模式 (MRM) 检测，基质匹配标准溶液外标法定量。结果表明:在0.01~5 mg/kg范围内，丙炔氟草胺在苹果、葡萄、柑橘、甘蓝、小麦、大豆、土壤及水8种基质中的峰面积与其质量浓度间呈良好的线性关系 (R2 > 0.997 6)。在0.01、0.1和1 mg/kg添加水平下，丙炔氟草胺在8种基质中的日内平均回收率为82%~104%，相对标准偏差 (RSD) (n = 5) 为1.1%~7.8%；日间平均回收率为77%~109%，RSD (n = 15) 为0.1%~9.2%。方法的定量限 (LOQ) 为0.000 3~0.003 2 mg/kg，均低于美国、中国、日本及欧盟等国家和地区的最大残留限量值 (MRLs)。本方法简便、稳定、灵敏，能够满足实际检测需求。同时，对大田土壤分析的结果表明，丙炔氟草胺在土壤中的半衰期为23.9 d，属易降解农药。     

Dissipation and movement of flumioxazin in soil at four field sites in Chile

BACKGROUND: Flumioxazin is a soil-applied herbicide recommended for broadleaf weed control in soybeans and peanuts, and was recently introduced for vineyard weed management. Considering the limited information available in relation to flumioxazin field soil behaviour, the main objectives of this study were to determine the persistence, adsorption and movement of flumioxazin in soil in four Chilean vineyard production areas. RESULTS: DT(50) values ranged from 10.6 +/- 1.0 to 32.1 +/- 3.1 days between localities, being correlated with rain events, time between herbicide application and first heavy rain event, and soil pH. Flumioxazin soil residue found at 90 days after application (DAA) varied from 9.6 to 24.9% of the initial amount applied, and depended on the total rainfall amount that occurred during the first 90 DAA. Herbicide leaching below 15 cm was approximately 45% of the flumioxazin detected at 90 DAA in the whole soil profile. Flumioxazin maximum leaching soil depth was 45 cm at all locations. K(d) values varied from 2.54 to 6.51 mg L(-1), depending on localities and soil profile depth, and correlated positively with organic carbon and clay content. CONCLUSIONS: These results indicate that flumioxazin is a herbicide with low environmental risk owing to its short DT(50), reduced soil residues 3 months after application and low effective dose.     

Weed control in summer-sown soybeans with flumioxazin plus acetochlor and flumiclorac-pentyl plus clethodim

Field trials were conducted in Taigu, Shanxi province, China, to evaluate the efficacy of flumioxazin plus acetochlor and flumiclorac-pentyl plus clethodim applied to summer-sown soybeans at pre- and postemergence. It was demonstrated that tank-mixing flumioxazin at 50 g ai ha^-1 and acetochlor at 800 g ai ha^-1 created an effective soil-applied herbicide for weed control in soybean crops. The control efficacy was better than when the herbicides were applied individually, and no injury was caused to the soybeans. Flumiclorac-pentyl at 50 g ai ha^-1 plus clethodim at 70 g ai ha^-1 suppressed both broad-leaved weeds and grass weeds with an increased efficacy of more than 90%. Flumiclorac-pentyl applied alone or tank-mixed caused some injury to soybean seedlings, but the soybeans recovered 2–3 weeks after treatment and there was no reduction in the yield.     

二甲戊灵、扑草净与丙炔氟草胺的配比筛选及在油莎豆田的应用效果

为探索和论证二甲戊灵、扑草净与丙炔氟草胺三者复配的合理性及三者复配制剂对油莎豆Cyperus esculentus var. sativus田杂草的防效和对油莎豆的安全性,本试验依据除草剂室内活性测定标准并借鉴除草剂防治大豆田杂草田间药效试验准则,进行了一系列试验。结果表明,二甲戊灵、扑草净与丙炔氟草胺三者联合作用对稗草Echinochloa crus-galli、苘麻Abutilon theophrasti、藜Chenopodium album 3种杂草表现为相加或增效作用,当三者混配比例为30∶30∶1时联合作用为增效,为最佳比例。此比例下的36.6%二甲戊·扑·丙炔SC对油莎豆田一年生杂草有较好的防效,试验有效剂量在1 647.0~1 921.0 g/hm2范围内,对油莎豆出苗、生长较安全;施药后40 d对一年生杂草的防效为91.3%~97.7%。由此可见,二甲戊灵、扑草净与丙炔氟草胺三者联合研制新药剂具有可行性,能扩大杀草谱和应用范围,可用于油莎豆田杂草防控,适宜用量1 647.0~1 921.0 g/hm2。     

丙炔氟草胺在大豆和土壤中的残留及消解动态

通过在山东德州、黑龙江哈尔滨和辽宁海城2年3地的田间试验，采用QuEChERS-高效液相色谱-串联质谱 (QuEChERS-HPLC-MS/MS) 法，研究了丙炔氟草胺在大豆和土壤中的残留及消解动态。结果表明: 在0.000 3、0.01和0.1 mg/kg添加水平下，丙炔氟草胺在大豆植株、青大豆、大豆籽粒和土壤中的日内平均添加回收率为89%~112%，日内相对标准偏差(RSD) (n = 5) 为1.3%~5.3%；日间平均添加回收率为85%~110%，日间RSD (n = 15) 为0.40%~4.8%。丙炔氟草胺在大豆植株、青大豆、大豆籽粒和土壤中的定量限 (LOQ) 均为0.000 3 mg/kg，能够满足农药残留限量标准的要求。丙炔氟草胺在大豆植株和土壤中的消解动态均符合一级反应动力学方程，在大豆植株和土壤中的消解半衰期分别为 5.8~11.8 d和 15.8~24.8 d。采用480 g/L丙炔氟草胺悬浮剂按推荐高剂量 (有效成分60 g/hm2) 及其1.5倍推存剂量 (有效成分90 g/hm2) 于播后苗前施药1次，收获期采样时，丙炔氟草胺在大豆植株、青大豆、大豆籽粒和土壤中的最终残留量均低于中国国家标准中规定的丙炔氟草胺在大豆上的最大残留限量 (0.02 mg/kg)。