A Study Of Injury Of Acetchlor To Rape And Its Prevention And Control Technologies

In this dissertation, the safeners, microbial agents and plant growth regulators were used to relieve phytotoxicity caused by acetochlor on rape in culture dish, pot culture and field trial.In culture dish, the influence of acetochlor on rape with its concentration from 10 mg/L to 3200mg/L was tested. The results showed that acetochlor had inhibition effect to rape roots and shoots, and the inhibition effects increased with increase of acetochlor concentration, and the inhibition effects to rape roots were higher than to rape shoots. On this basis, the detoxification effects of eight safeners to acetochlor were assayed with rape in culture dish with soaking seed and mixing with acetochlor. The results showed that, when safeners were mixed with acetochlor,20mg/L (a.i.) dichlormid could relieve the phytotoxicity of 200mg/L acetochlor (a.i.) on rape roots and shoots, the recovery rates were 12.69% and 60.95% respectively.50mg/L (a.i.) fenchlorazole-ethyl could relieve the phytotoxicity of 100mg/L acetochlor (a.i.) on rape roots and shoots, the recovery rates were 15.84% and 104.68% respectively.100mg/L.(a.i.) cloquitocet-mexyl could relieve the phytotoxicity of 400mg/L (a.i.) acetochlor on rape roots and shoots, the recovery rates were 2.8% and 20.66% respectively.50mg/L.(a.i.) benoxacor could relieve the phytotoxicity of 200mg/L (a.i.) acetochlor on rape roots and shoots, the recovery rates were 100.34% and 107.02% respectively. When safeners soaking seed, the rape seed was soaked by 20mg/L (a.i.) mefenpyr-diethyl and acetochlor was 400mg/L (a.i.), the recovery rates of rape roots and shoots were 18.08%, 77.26% respectively. The rape seed was soaked by 20mg/L (a.i.) AD-67 and acetochlor was 200mg/L (a.i.), the recovery rates to rape roots and shoots were 26.06%、92.06% respectively. The rape seed was soaked by 400mg/L.(a.i.) fenclorim and acetochlor was 400mg/L (a.i.), the recovery rates to rape roots and shoots were 12.67%、33.73% respectively. But detoxification effects of all safeners were not ideal, so they could not be applied in field.In pot culture, the influence of acetochlor on rape with its concentration from 465 g/hm2 to 2145 g/hm2 was tested. The results showed that acetochlor had inhibition effect to rape’s plant height and fresh weight, and the inhibition effects increased with increase of acetochlor concentration, and the inhibition effects on rape’s plant height were higher than on rape fresh weight. On this bais, the mitigation effects of one kind of microbial inoculants (Yiwei) and three kinds of plant growth regulators (brassinolide, gibberellin, VitaCat) to acetochlor were assayed with rape in pot culture. The results showed that, when Yiwei seed dressing, Yiwei could remarkablely relieve the phytotoxicity of acetochlor on rape with different concentration, and the recovery rates increased with dosage of Yiwei. When 3kg rape’s seeds were been dressing with 25g Yiwei, the recovery rates were better than others. When brassinolide sparying, brassinolide was 0.021g/hm2, the mitigation effects were better than others. When gibberellin sparying, gibberellin was 168g/hm2, the mitigation effects to rape’s plant height were higher than others, and gibberellin was 21g/hm2, the mitigation effects to rape’s fresh weight were higher than others. But VitaCat could not relieve the phytotoxicity of acetochlor on rape.In plot culture, the connection of dosage of acetochlor and phytotoxicity of acetochlor to rape, content of GSH, GSSG, activity of GST, residue of acetochlor with acetochlor concentration from 525 g/hm2 to 3150 g/hm2 were studied. The results showed that there was a positive correlation between dosage of acetochlor and phytotoxicity of acetochlor to rape, content of GSSG, residue of acetochlor, and there was a negaive correlation between dosage of acetochlor and content of GSH, activity of GST, After sowing 12 days, there was a strong inhibition effects of acetochlor on rape, and GSH contents were lowest than other days, activities of GST were lowest than other days, and GSSG contents were highest than other days. On this basis, there were tested residue of acetochlor in rape and contents of GSH, GSSG and activities of GST in rape’s leaf with Yiwei seed dressing and brassinolide spraying, and primarily discussed the mechanism of Yiwei and brassinolide to relieve the phytotoxicity of acetochlor. The results showed that after being treated with Yiwei, Yiwei significantly increased GSH contents, outstanding improved GST activities, obviously decreased GSSG contents, and the residue of acetochlor was lower than the control group. After dealing with brassinolide spraying, brassinolide significantly increased GSH contents, outstanding improved GST activities, decreased GSSG contents, and the residue of acetochlor was no different with the control group.In field trail, the mitigation effects of Yiwei, brassinolide, gibberellin to acetochlor were assayed with rape. The results showed that Yiwei, brassinolide, gibberellin effectively relieved the phytotoxicity of acetochlor on rape. When 1-3kg rape’s seeds were been dressing with 25g Yiwei, the recovery rates were best than others, and the recovery rates to rape’s plant height and fresh weight were 43.51%、91.30% respectively. When brassinolide was 37.5 g/hm2, the recovery rates were better than others. When gibberellin was 150g/hm2, the recovery rates were better than others.The above tests showed that using Yiwei, brassinolide and gibberellin with seed dressing or spraying, all of them could effectively relieve the phytotoxicity of acetochlor to rape.