| In order to study the effects of hormone herbicide on the safety of naked oats, shell rate, grain yield and weed control, Baiyan No.2 was used as material. The field experiment of herbicides was coducted in Crop Production Farm of Yuzhong County, Gansu Province, we studied the weed control effect, shell rate, grain yield under different kinds of herbicides and dosage; and seedling physiological and biochemical variations under different herbicides and dosage treatments were also studied through pot experiment.The main results were as follows:(1) Hormone herbicide significantly influenced the safety of oats. After spraying high concentrations of 2, 4-d butyl ester, oats appeared some symptoms, such as medicine spot and leaf redness, the top sagging. From filling stage to maturity, under the treatment of 2, 4-d butyl ester, oats appeared lemma hardening, the top of spike tortuosity, the head top distortion, spikelets floret strain rate and shell rate increasing. Shell rate at high concentrations of 2, 4-d butyl ester was the highest(11.04%), significantly higher than other herbicides. Therefore, 2, 4-d butyl ester is unfavorable to use in naked oat field.(2) Different kinds of herbicides and dosage had significant effects weed control effect. Control effect increased with the increasing concentration of herbicide. medium and high concentrations of 40% Bromoxynil octanoate plus MCPA-sodium had the highest control effect. After 15 d, the plant control effect reached 80.00% and 90.33%; after 30 d, the plant control effect reached 92.00% and 99.00%, respectively.After 30 d, the plant control effect reached 85.33% and 92.67%, the fresh weight efficacy reached 77.00% and 89.00% respectively. High concentration of benzene azole sodium 2 armor take second place, after 15 d and 30 d, the plant control effect reached 70.33% and 87.67% respectively; after 45 d, the plant control effect and the fresh weight efficacy was 83.00% and 86.67% respectively.(3) Different kinds of herbicides and dosage had significant effects on oat seed yield. Seed yield decreased with the dosage rising under the treatments of 20%Fluroxypyr.Under high dosage 20%Fluroxypyr treatment, the seed yield was 3212.2kg/hm2, and 2861.9 kg/hm2 under low dosage. The low dosage of 72% of 2, 4-d butyl ester produced seed yield by 3118.0 kg/hm2, high dosage by 1829.9 kg/hm2.Under the low concentration of 50% Quinclorac treatment, oat seed yield was 2071.5 kg/hm2, and decreased to 1135.6 kg/hm2 under high concentration. Under 50%Benazolin and 40% Bromoxynil octanoate plus MCPA-sodium treatment, oat see yield rose first and then declined. Medium concentration Benazolin(450ml/hm2) and Bromoxynil octanoate plus MCPA-sodium had highest seed yield, by 3517.2 kg/hm2 and 3650.7 kg/hm2.(4) The influence of different herbicides on oat seedling physiological and biochemical indexes was different. Herbicides could lead to variation of leaf physiological and biochemical index in oat, With the increasing days after treatment, POD, SOD activity increased first, and reduced later on. CAT activity showed a slight decline before increase. MDA content rose up and reached the highest level 30 days after treatment. Higher dosage heibicides had severer stress on oat than lower ones. Among 4 heibicides, MCPA-Na had higher effect on oat leaf enzyme activity and not suitable for oat field.(5) Combined with the safety,weed control effect and seed yield, 40% Bromoxynil octanoate plus MCPA-sodium with 1350ml/hm2 had best comprehensive effect in the field of naked oats. |
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