In order to evaluate the negative effect of herbicides, five commonly herbicides (tribenuron-methyl, fluroxypyr, isoproturon, puma super and chlorotoluron) were used to investigate their effects on grain yield and physiological characteristics of weak-gluten wheat Yangmai 13 and strong-gluten wheat Yannong 19. Results showed that (1) all of the five herbicides exhibited inhibitory effects against plant height, and the high-dosage treatment showed significant inhibitory effect with weaker inhibitory effect by the low-dosage treatment. Among the five herbicides, isoproturon with 2 times recommended dosage had the greatest inhibitory rate of 9.6%. The impacts of the majority herbicides on Yannong 19 were more serious than on Yangmai 13. (2) All of the 5 herbicides reduced the SPAD values of Yannong 19 significantly 5 days after treatment (DAT). Tribenuron-methyl, chlorotoluron, isoproturon reduced the SPAD values of Yangmai 13 significantly, but the effects of fluroxypyr and puma super were not significant. (3) Herbicides treatments reduced photosynthetic rate of the 2 tested wheat varieties and this effect of herbicides showed a certain relationship to be dosage. The herbicides' effect on Yannong19 was greater than on Yangmai 13 and the strongest inhibition effect was twice the recommended dosage of isoproturon treatment with the inhibition rate of 27%. The impacts of herbicides on the physiological indicators of wheat plant were more obvious at the initial of the treatment, followed by a gradually slowing effect, at the late of the treatment most of the indicators could be restored to the control level. (4) The grain yield of wheat were reduced all herbicide treatments, and isoproturon and tribenuron-methyl showed greater inhibitory effect on wheat grain yield, then followed by chlorotoluron, puma super and fluroxypyr.

为评价除草剂的负效应,研究了大田条件下苯磺隆、使它隆、异丙隆、骠马和绿麦隆5种除草剂春季施用对强筋小麦烟农19和弱筋小麦扬麦13的籽粒产量及相关生理特性的影响。结果表明,5种除草剂处理后对小麦株高均有一定的抑制作用,表现为高剂量抑制作用强,低剂量抑制作用较弱,其中抑制作用最强的为异丙隆2倍量处理,其抑制率达对照的9.6%;苯磺隆、绿麦隆、异丙隆药后5d显著降低了小麦叶片SPAD值,使它隆及骠马处理则不明显。小麦叶片净光合速率均受到除草剂的抑制,仍以异丙隆2倍量抑制作用最为显著。除草剂对小麦植株生理指标的影响效应随着施药时间的延长逐渐减弱,整体表现为喷施除草剂后15d之前较为显著,其后多数指标能恢复至对照水平。无草条件下施用除草剂显著降低了小麦籽粒产量,减产最明显的是异丙隆和苯磺隆处理,其次为绿麦隆、骠马和使它隆。供试2个小麦品种中,扬麦13表现出比烟农19对除草剂具有更强的耐受性。

A field experiment was conducted to study the effect of 2,4-D butyl and sigma spray-time on the yield components, grain yield, quality and leaf net photosynthetic rate ( Pn ) of high quality wheat “Linyou 145”. Results show that Pn decreases under three spray-time of 2,4-D butyl, and decreasing rank increases with spring-time delay. Leaf and flag leaf Pn during early and middle filling stages drops compared with the control 1~15 days after sigma application in three spray-time. 2,4-D butyl applied in three spray-time shows little effect on filling parameters. Sigma prolongs filling period ( S ) and effective filling period ( Se ) but decreases average filling rate ( R ) and effective filling rate ( Rs ). Herbicide spray-time has greater effects on 1000-kernel weight and per-hectare ear than per-ear kernel. Yield decreases with later 2,4-D butyl spray. Sigma sprayed on Nov. 15 and March 20 increases flag leaf Pn during late filling stage compared with the control, and respectively increases yield by 157.44 kg・hm -2 and 222.34 kg・hm -2 , but yield decreases by 512.71 kg・hm -2 when sprayed on April 4. Wheat quality is improved when 2,4-D butyl is sprayed on Nov. 15 and March 20, but decreases when 2,4-D butyl is used on April 4 and sigma used in three spray-time. In summary, 2,4-D butyl and sigma sprayed on April 4 has a more obvious effect on wheat quality than sprayed on Nov. 15 and March 20. Sigma sprayed on April 4 produces the lowest yield and quality of wheat.

间试验研究了除草剂2,4-D丁酯(A)和世玛(B)11月15日、次年3月20日和4月4日3个使用时期对小麦“临优145”产量结构、籽粒产量、品质和叶片净光合速率( Pn )的影响。结果表明: 2,4-D丁酯3个使用时期均使小麦叶片 Pn 降低, 且随使用期推迟降幅越大; 世玛3个使用时期在1~15 d使叶片和旗叶灌浆前中期 Pn 较对照降低, 灌浆后期B 1 (11月15日)和B 2 (3月20日)处理旗叶 Pn 高于CK处理。2,4-D丁酯3个使用时期对灌浆参数影响相对较小, 而世玛使籽粒灌浆持续期( S )和有效灌浆持续期( Se )延长, 使平均灌浆速率( R )、有效灌浆期灌浆速率( Rs )降低。除草剂使用时期对小麦千粒重和成穗数影响较大, 且随使用时期推迟影响越大, 对穗粒数影响较小。随使用期推迟2,4-D丁酯使小麦产量降低越多, 世玛的B 1 和B 2 处理小麦产量分别提高157.44 kg?hm -2 和222.34 kg?hm -2 , B 3 处理(4月4日)则减产512.71 kg?hm -2 。2,4-D的A 1 和A 2 处理使小麦籽粒品质改善, A 3 和世玛的3个使用时期均使小麦品质指标降低。因此, 2种除草剂11月15日使用对小麦各项指标影响较小, 次年4月4日使用影响最大, 尤其是B 3 处理使产量最低, 品质最差。