Study on Safety of Imidazolinone Herbicides to Succeeding Crops

The field trial on effect of residues of imidazolinone herbicides in soil on succeeding crops were conducted during 19962000. The results showed that the sensitivity of succeeding crops to the herbicides was different. Wheat, corn and pumpkin could be planted safely 12 months after and rape, beet, Chinese cabbage, flax and potato planted safely 24 months after the applying of imazamox 40 g/hm2 and 60 g/hm2 . The sensitive crops, such as rape, beet, Chinese cabbage, flax and potato, might be injured at the higher dosages of imazamox 80 g/hm2 and 120 g/hm2 after 12 months. Under the commended dosage of imazethapyr/imazamox 50 g/hm 2 , it is safe that planting wheat and corn after 12 months and planting rape, pumpkin, potato after 24 months. However, beet, Chinese cabbage and flax could be injured seriously after 24 months. At double dosage of imazethapyr/imazamox 100 g/hm2 , there were severely harmful to sensitive crops besides wheat and corn in this experiment after 12 and 24 months. At the commended dosage of imazethapyr 75 g/hm2 , wheat and corn could be planted safely after 12 months, and planted pumpkin and potato was safe 24 months later. Serious injury was observed 12 and 24 months after the applying of imazethapyr to rape, beet, Chinese cabbage and flax.