乙草胺不同时期施用对大豆安全性和杂草防效影响

为探讨乙草胺苗前和苗后不同时期施用对大豆安全性和杂草防效影响,采用随机区组田间试验设计,乙草胺苗前单独施用和苗前苗后连续施用及连续施用并与氟磺胺草醚、精喹禾灵、异噁草酮分别混施,每间隔7 d调查杂草防效,同步测定大豆生长和叶片超氧化物歧化酶(SOD)活性、过氧化物酶(POD)酶活性、丙二醛(MDA)含量。乙草胺连续施用较单独施用显著提高杂草防效,连续施用并与氟磺胺草醚、异噁草酮混施后期杂草防效更显著,其中乙草胺连续施用并与氟磺胺草醚混施杂草防效最佳,第35天杂草株防效仍可达90.16%,大豆株高及干重与人工除草相比无显著差异。叶片SOD、POD活性先升后降,MDA含量增加,至施药后28 d与对照均无显著差异。乙草胺苗前苗后连续施用并混施氟磺胺草醚或异噁草酮显著提高大豆安全性及除草效果。

Weed control and soybean response to application of acetochlor in different periods

To explore the application of acetochlor in the pre-emergence and post-emergence periods to the safety of soybeans and improve the control of weeds in soybean fields in the late spring.By using the randomized block group field trial design with three treatments, the study used the acetochlor pre-emergence application for the first treatment, both pre-emergence and post-emergence for the second treatment, and two applications which were mixed with fomesafen, quizalofop-p-ethyl and clomazone respectively for the third treatment. The weed control was investigated at intervals of 7 d,and the soybean growth and superoxide dismutase(SOD) activity, peroxidase(POD) enzyme activity,and malondialdehyde(MDA) content in the leaves were measured simultaneously. The sequential application of acetochlor compared with acetochlor applied pre-emergence alone was increased the weed control, and the third treatment which mixed with fomesafen or clomazone was more effective in improving the late growth period of weeds control. Among them, the sequential application of acetochlor and the combination of fomesafen were the best for weed control, and the weed control on the 35 th day was still up to 90.16%. The soybean plant height and dry weight had no significant difference with artificial weeding. The activities of SOD and POD in leaves increased firstly and then decreased, and with the increased content of MDA. There was no significant difference between the leaves and the control of application after 28 d. The application of acetochlor in two periods and with the combination of fomesafen and clomazone were significantly improved for the safety of soybean and weed control.