10%噁唑·氰氟+480 g/L灭草松对旱直播稻田杂草防除和水稻产量的影响

Effect of 10%Metamifop·Cyhalofop-Butyl Plus 480 g/L Bentazone on Weed Control and Yield of Dry-Seeded Rice

为了有效控制旱直播稻田杂草,采用大田试验,设置不同剂量的10%噁唑酰草胺·氰氟草酯乳油+480 g/L灭草松水剂,以2.5%五氟磺草胺油悬浮剂+480 g/L灭草松水剂为对照,观察不同除草剂组合对旱直播稻田杂草的防除效果及对水稻产量的影响。结果表明,10%噁唑酰草胺·氰氟草酯乳油300~450 g a.i./hm^2+480 g/L灭草松水剂1440 g a.i./hm^2对旱直播稻南粳9108无药害,具有较好的杂草防除效果,株防效和干重防效均达98%以上,而2.5%五氟磺草胺油悬浮剂37.5 g a.i./hm^2+480 g/L灭草松水剂1440 g a.i./hm 2对杂草的株防效和干重防效分别为85.5%和87.3%。10%噁唑酰草胺·氰氟草酯300~450 g a.i./hm^2+480 g/L灭草松水剂1440 g a.i./hm^2处理的水稻产量与人工除草间无显著差异,而2.5%五氟磺草胺+480 g/L灭草松水剂处理的水稻产量较人工除草显著降低,残存杂草造成水稻叶片光合速率降低、根系氧化力减弱是该处理下水稻减产的重要原因。

A field experiment was conducted to evaluate the efficacy of metamifop·cyhalofop-butyl 10% emulsifiable concentrate(EC) plus bentazone 480 g/L aqueous solutions(AS) at different doses on weed control and grain yield of dry direct-seeded rice. The penoxsulam 2.5% oil dispersion(OD) plus bentazone 480 g/L AS was used as control(CK). Metamifop-cyhalofop-butyl at 300 to450 g a.i./hm^2 mixted with bentazone at1 440 g a.i./hm^2 was selective to ’Nanjing 9108’ rice and provided adequate weed control;efficacy measure in terms of plant density and dry weight was above 98%compared to 86% and 87%,respectively,obtained with penoxsulam(37.5 g a.i./hm^2) plus bentazone(1 440 g a.i./hm^2). Moreover, no significant difference in rice yield was observed between plots treated with metamifop·cyhalofop-butyl plus bentazone and those where weeds were manually removed. Penoxsulam plus bentazone,however,significantly reduced rice yield compared with manual weed control. An important reason for the reduction of rice yield under the treatment was a lower leaf photosynthetic rate and root oxidation activity caused by the survival weeds.