| Soybean is one of the most important oil crops and grain crops in our country. With the wide using of the Soybean Herbicide, people paid more and more attention to the non-target effects of herbicides. Soybean root rot is a major disease of the soybean seedlings. In order to explore the impact that the Soybean Herbicide makes on the Fusarium oxysporum, this project studies in the interactive relationship between the Soybean Herbicide and the Fusarium oxysporum. In this passage, there are four types, five kinds of herbicides which are used in the soybean field usually. They are diphenyl ether herbicides fomesafen,amide herbicides acetochlor and metolachlor,triazine herbicides metribuzin,organic heterocyclic herbicides clomazone. I studied in the impact of the Fusarium oxysporum on mycelium growth,dry weight of the mycelium,growth,defense enzymes. And I also studied in the field investigation of its soybean root rot disease and yield effects.1. The test on Fusarium oxysporum mycelium growth showed that the highest toxicity function is acetochlor,EC50 was 251.36 mg/L,and followed by metolachlor,clomazone,metribuzin,the weakest toxicity function was fomesafen, EC50 was 2468.88 mg / L.2. The mycelium dry weight test's results showed that all of the different kinds of herbicides can produce the inhibiting function to the Fusarium Oxysporum's mycelia, and the inhibiting function will be more and more stronger with the increasing of the dosage. Dose of 400 mg / L, the highest inhibition rate was acetochlor, followed by clomazone,metolachlor,metribuzin, the weakest inhibiting function was fomesafen.3. The height and fresh weight of Soybean's impact test showed that the inhibiting function will increase with the increasing of the dosage, the inhibiting function decreased with the growth of soybean. Metolachlor dosage of 3750 mL/hm2 in 15d on the height and fresh weight of the highest inhibition rate were 20.18% and 28.92%.Fomesafen dosage of 1500mL/hm2 in 15d on the height of the lowest inhibition rate was 4.44%.Metribuzin dosage of 450g/hm2 in 15d on the fresh weight of the lowest inhibition rate was 1.37%.Acetochlor dosage of 1800mL/hm2 in 45d on the height of the highest inhibition rate was 7.99%.Metolachlor dosage of 3750mL/hm2 in 45d on the fresh weight of the highest inhibition rate was 11.34%.Fomesafen dosage of 1500mL/hm2 in 45d on the height of the lowest inhibition rate was 0.82% .Clomazone dosage of 750 mL/hm2 in 45d on the fresh weight of the highest inhibition rate was -2.54%.4. The field findings indicated that disease index in the two-leaf stage compared with the control from low to high soil treatment were fomesafen and acetochlor mixture dosage of 1800+1500,1200+1500,1800+2100,1200+2100mL/hm2;fomesafen dosage of 1800,1500 mL/hm2;metribuzin dosage of 600 g/hm2;fomesafen dosage of 1200 mL/hm2;the manual weeding plot;fomesafen and metolachlor mixture dosage of 1800+2500 mL/hm2.Disease index in the two-leaf stage compared with the control from low to high stem and foliage treatment agent were fomesafen dosage of 1800,1500 mL/hm2;fomesafen and clomazone mixture dosage of 1200+800,1800+800mL/hm2. Disease index in the third-leaf stage lower than the control soil treatment was metribuzin dosage of 600 g/ hm2. The disease indexes of stem and foliage treatment and clomazone in the two-leaf stage and third-leaf stage were both higher than the control, and it will be lower and lower with the increasing of the dosage. 5. After using the herbicides, the effect of herbicides soybean yield components results showed that acetochlor dosage of 1500 mL/hm2,metribuzin dosage of 500 and 600 g/hm2,metolachlor dosage of 2500 mL/hm2,metribuzin and acetochlor mixture dosage of 600 g/hm2+2100 mL/hm2,metribuzin and metolachlor mixture dosage of 600 +2500 and 600 g/hm2+3500 mL/hm2,clomazone dosage of 1200 mL/hm2,the manual weeding plot on the various yield components were better than the control.6. After using the herbicides, the test of the soybean production in field showed that most of the productions of herbicide application were higher than control, there are significant differences between the production treatments. The highest yield production was soil treatment Metribuzin and metolachlor mixture dosage of 600g/ hm2 +2500 mL / hm2, was 6.61kg was increased by 34.9%. The lowest yield production was stem and foliage treatment fomesafen. Its dosage of 1800mL/ hm2 was 3.93kg, and it was reduced 19.8% than the control.7. The test results of 5 enzymes activity in defense enzymes measurement showed that the application of herbicide treatment could cause body of soybean PPO, POD, CAT, PAL, SOD enzyme activity changes of different degree. In addition to CAT enzyme activity slightly increased, the left enzymes activity were increased at first and then decreased. With both of treatment that herbicides and inoculated-pathogen made, In addition to PAL enzyme activity slightly increased, the left enzymes activity were increased at first and then decreased. But its enzyme activity is different from the application of herbicide treatment. It can cause a change in soybean's defense mechanisms to indicate the pathogen infection... |
PDF Full Text Request