Study On Weed Control Effect Of Herbicides Mixture In Oats Field

In order to select suitable,safe and efficient mixed herbicides and further understand their effects on safety,physiological and yield in oat,this thesis studied the mixture type of herbicides,weed control effect,safety and production of different herbicides with different mixture proportion.The main results were as follows:?1?The mixing action type of mixed herbicide is generally additive effect.Among them,cotoxicity coefficient of s-metolachlor and bensulfuron was 132.6,showing a synergistic effect.The mixture treatment was generally showed additive effects through Gowing method by measuring fresh weight inhibition rate of weeds.Among them,the mixture of bensulfuron and s-metolachlor,2,4-d butyl lactate and ethyl carboxylfluoroether emulsion showed synergistic effects.?2?The effect of herbicide treatment on fresh weight inhibition of weeds was significant?P<0.05?.The inhibitory effect of mixed herbicide treatment on weeds was generally better than that of single agent.The fresh weight inhibition ratio of cleavers by Dimethoxychloride and bensulfuron mixture reached 100%;2,4-D butyl ester EC and fluroxine EC mixture also had 100%control of Segmental fennel.?3?Under herbicides stress,the plasma membrane permeability,MDA content,proline content and soluble sugar content of oat increased with the increasing concentration of herbicides.Under mixture treatment of 2,4-d butyl and ethyl carboxyl fluoride(877m L·hm^-2+600 mL·hm^-2),the plasma membrane permeability,MDA content,proline content and soluble sugar content were the highest?46.15%,0.15 mol/gFW,83.41 g/gFW,2.29%?,significantly higher than the control.?4?2,4-d butyl lactate and b-carboxyflurane mixed with high concentration were harmful to oat seedlings,but lower concentration was safe.Herbicides mixture could greatly improve weed control effect compared with their single agents.The best combination was s-metolachlor and bensulfuron mixed with 25.4:1 and 50.8:1.Its fresh weight control efficiency was 90.99%and 83.27%after 30 days of treatment.At the same time,ethyl carboxyl fluoroether emulsion and 2,4 D butyl emulsion mixed with 1:8.3 had a good weed control effect,showing 81.12%and 91.76%plant control and fresh weight control respectively.The dimethyl octanoyl bromide EC and the quincloric acid WP mixed by 4.98:1 led to 86.23%and 98.81%plant control and fresh weight control respectively.Dimethyl tetrachlorm and bensulfuron mixed with 4.8:1 had the best weed control effect.?5?The suitable mixing ratio could not only improve the weed control,but also increase oat yield.S-metolachlor mixed with bensulfuron in higher concentration gave90.99%and 83.27%plant control and fresh weight control respectively 30 days after treatment;Oat hay yield reached 12125.3 kg·hm^-2,and seed yield was 4541.93 kg·hm^-2,increased by 26.86%and 11.83%respectively compared with the control.?6?Comprehensively considering safety,weed control effect and oat yield increasing,the best combination for hulled oat was 96%s-metolachlor(900 ml·hm^-2)+10%bensulfuron(340 ml·hm^-2)and 57%2,4-D butyl emulsion(438.5 ml·hm^-2)+10%ethyl carboxyl fluoroether emulsion(300 ml·hm^-2).40%dimethyl octanoyl bromide EC(1400ml·hm^-2)+50%quincloric acid WP(225 ml·hm^-2)gave the best effect in naked oats field.