八种除草剂对小麦田三种抗精噁唑禾草灵杂草的生物活性

为筛选能有效防除抗精噁唑禾草灵杂草的除草剂,采用温室盆栽法测定菵草(敏感S_w、抗性R_w)、日本看麦娘(敏感S_r、抗性R_r)、耿氏硬草(敏感S_y、抗性R_y)对精噁唑禾草灵的抗性水平,并研究了8种除草剂对这3种抗性杂草的生物活性。结果显示,3种杂草抗性种群对精噁唑禾草灵的抗性指数均大于33.7,已达高抗水平。3种杂草抗性种群均对同类乙酰辅酶A羧化酶类抑制剂唑啉草酯和炔草酯产生了11.6~56.5倍不等的高水平抗性。对部分乙酰乳酸合成酶类抑制剂产生了2.0~4.8倍的低水平抗性,氟唑磺隆对3种杂草抗性种群防效较差,GR_(90)为67.31~114.39g(a.i.)/hm~2;啶磺草胺仅对Rr种群防效较好,GR_(90)为4.67 g(a.i.)/hm~2;甲基二磺隆对3种杂草抗性种群防效均较好,但对Rr种群存在抗性风险,已出现2.0倍低水平抗性;磺酰磺隆对Ry和Rr种群防效较好;丙苯磺隆对Rr种群防效好。细胞分裂抑制剂氟噻草胺对3种杂草抗性种群防效均最好,在田间推荐剂量120 g(a.i.)/hm~2下可达90%以上的防效。

Biological activities of eight herbicides to three species of fenoxaprop- P-resistant weeds in wheat fields

In order to screen effective herbicides to fenoxaprop-P-resistant grasses, whole-plant dose response experiments were conducted in greenhouses, and the resistance of Beckmannia syzigachne (sensitive population S_w, resistant population R_w), Alopecurus japonicus (S_r, R_r) and Sclerochloa kengiana (S_y, R_y) to fenoxaprop-P-ethyl were evaluated, and the three resistant weed species were also used to study the biological activities of eight kinds of herbicides. The results showed that all the resistant populations of the three grass species had evolved high resistance to fenoxaprop-P-ethyl, and the resistance indexes were greater than 33.7. The three resistant populations had evolved high resistance to ACCase inhibitors pinoxaden and clodinafop-propargyl (the resistance index were 11.6-56.5), but low resistance to some ALS herbicides (the resistance index were 2.0-4.8), while flucarbazone-Na displayed poor control effect to the resistant populations, with a GR₉₀ from 67.31 to 114.39 g (a.i.)/hm²; pyroxsulam could control the R_r population effectively, and the GR₉₀ was 4.67 g (a.i.)/hm²; mesosulfuron-methyl showed high efficacy against the three resistant populations, but there was risk of resistance in R_r population, with a resistance index of 2.0; sulfosulfuron could well control R_y and R_r populations, while propoxycarbazone-sodium showed high efficacy in controlling R_r population. Flufenacet was the only herbicide that had ideal effects to all R_w, R_r and R_y populations with a control efficacy of more than 90% at the recommended field rate with 120 g (a.i.)/hm².