关键词: 咪唑乙烟酸, 冀谷33, 生长发育, 后茬作物, 安全性

Abstract: 【Objective】 Jigu 33 is a new imazethapyr-resistant millet variety. Chemical seedling thinning and weed control can be realized by applying proper imazethapyr herbicides in large-scale cultivation and production. The objective of this study is to examine the effect of imazethapyr on the growth of millet Jigu 33 and its safety on succeeding crops, and to provide references for the application and promotion of Jigu 33.【Method】The experiment was carried out at the Qiema test station of the Institute of Millet Crops of Hebei Academy of Agricultural and Forestry Sciences with 6 dose levels of imazethapyr (0, 56.25, 75, 112.5, 150, 225 g a.i./hm²) from May 2013 to June 2015. The effect of imazethapyr on millet Jigu 33 growth was tested in the field. Jigu 33 seedling height and fresh weight were investigated on 7, 10, 13, 16, 20, 25 and 30 DAS (days after spraying); plant height, spike length, spike diameter and yield were investigated in the mature period; the residue of imazethapyr in millet, chaff, plant and soil were detected. Its safety on succeeding crops (Chinese cabbage, Jigu 19, Jigu 33, sugar beet, sorghum, maize, wheat and cotton) was tested on 30, 60 days and 1 year after sowing in net room.【Result】The growth of millet Jigu33 was normal at 56.25 to 225 g a.i./hm² and there was no evident injury. The effect on Jigu 33 seedling height and fresh weight in different periods after spraying showed that there was no obvious difference between the treatment and control. The sensitive period for seedling height was at the early jointing stage from 13 to 16 DAS, and the sensitive period for seedling weight was on the late jointing stage and the early jointing stage from 20 to 25 DAS. Then the inhibition was lightened gradually, and the growth of millet Jigu 33 was normal at harvest time, the yield of which was higher than the control. The residue was only detected in plant at 225 g a.i./hm² dose level with (0.01±0.006) mg?kg^-1, which was less than LOQ. The inhibition on the succeeding crops was also lightened gradually as time progressed. The plant height of the succeeding crops one year after sowing had significant differences. Of all the succeeding crops, Chinese cabbage and sorghum were sensitive with significant yield loss. In the spraying imazethapyr field in the summer millets region, the rotation cropping of Jigu 33 could be wheat, maize and cotton.【Conclusion】The growth and yield of millet Jigu 33 was normal at 56.25 to 225 g a.i./hm². The inhibition on the succeeding crops was lightened gradually as time progressed. The rotation cropping of Jigu 33 could be wheat, maize and cotton. In production, more attention should be paid to the control of the dosage and the rational rotation.

Key words: imazethapyr, millet Jigu 33, growth and development, succeeding crops, safety