| Bradysia odoriphaga Yang et Zhang, belongs to Diptera Sciaridae Bradysia Winnertz. B. Odoriphaga severely threat the quality and output of Allium tuberosu m because it is an important underground pest and difficult to prevent in our cou ntry. Chemical insecticides always used as mainly prevention and control measures of B. odoriphaga in production. Long-term and single to use same chemical inse cticides, not only result in excessive pesticide residue of A. tuberosum, but also i ncrease resistance of target insects. At the same time, it makes a potential threat to the health of consumers. On the one hand, the study to determine indoor toxic ity of ozone against B.odoriphaga with three states and its impacts on the soil en vironment. it also determine how the ozone effect to A. tuberosum seed germinati on and early seedling. On the other hand, the study was determined the toxicity of 5 botanical insecticides to the different stages of B. odoriphaga and potted pes ticide effect experiments. Meanwhile the study on the temperature effect of veratri ne to B.odoriphaga and safety evaluation of veratrine to the soil microorganism a nd earthworm were evaluated in the laboratory also be tested. The objective of th is paper can provided theoretical basis and technical guidance for B.odoriphaga de contamination control. The main results are as follows:1.Ozone had the higher toxicity to 3th instar, pupa and adult of B.odoriphaga with LC50 values of 3.793 mg/L, 4.950mg/L and 61.518mg/m3 respectively.2.Different concentrations of ozone water treatment, the content of soil microorganisms were significantly different than control. The impacts of soil microorganism were treat by 2 mg/L of ozone water, the content of bacteria, fungi and actinomycetes was reduced by 39.14%、45.10% and 26.67% respectively compared with control group. After 4.5 mg/L of ozone water treat the soil, the content of bacteria, fungi and actinomycetes was reduced by 80.95% 、 86.80% and 60% respectively compared with control group. With different concentration of ozone water treatment of soil, the result shows that the content of soil p H value slightly increased, but not significantly difference were found with the control group; the content of organic matter was lower than the control group,but no significant difference between the two treatment groups;4.5 and 2 mg/L of ozone water, the content of NH+4-N was 17.03 and 18.79g/kg respectively, and lower than control with 20.96g/kg, but no significant difference between the two treatment groups; 4.5 and 2 mg/L of ozone water, the content of available P was 22.94 and 24.00g/kg respectively, a indistinctive lower than control group; 4.5 and 2 mg/L of ozone water, the content of active K was 121.89 and 89.53g/kg,and higher than the control which has significantly difference with 2 mg/L and 4.5 mg/L of ozone water, it shows that the content of active K was improved by ozone treatment.3.When effect of processing with ozone on germination and seedling growth of A.tuberosum were tested. Founding that immersion of seed into ozone water for 15 min get the highest effective which can effectively enhance A.tuberosum seed germination rate、root length and buds length with 87.78% 、 1.86 cm and 7.50 cm respectively. Effect of ozone water to seed germination and early seeding was declining in the order as following: 15min> 10min> 20min> 5min> 0min. It shows that in 15 min, ozone water can effectively facilitate the seed germination and early seedling growth. However,after15 min disposed, the promoting effect getting slower.4.In order to determine the pesticide toxicity, 5 kinds of botanical insecticides to different stages of B. odoriphaga was detected using the dripping ration liquid methods,and the controls were set up by traditional organophosphorus pesticide(chlorpyrifos and phoxim). Toxicity of 7 pesticides to the eggs of B. odoriphaga was declining in the order as following: veratrine> matrine> phoxim> Celastrus angulatus> chlorpyrifos>azadirachtin, veratrine showed higher toxicity to it with LC50 to 55.685mg/L. While toxicity of 7 pesticides to the 3th instars of B. odoriphaga was declining in the order as following: veratrine> matrine> phoxim> Celastrus angulatus> chlorpyrifos> azadirachtin.However, toxicity of veratrine was detected under different temperatures. Under three different given temperature, veratrine shows the positive temperature effect and the toxicity rising with the increasing of temperature. Meanwhile, this article which studied on the safety evaluation of A.tuberosum was tested by veratrine treatment, when concentration of veratrine less than or equal to 10 mg/L, it is not effect on the seed germination and early seedling growth of A.tuberosum. 5 kinds of botanical pesticides,veratrine had higher toxicity to eggs and 3th instars of B. odoriphaga and had a safety evaluation of A.tuberosum, it is worth to be extending and applicating.5.Text for safety evaluation of veratrine insecticides to soil. The results show edthat veratrine had low toxicity for earthworms, veratrine belong to the lower poi sonous pesticide category on soil microbe. it is a security pesticide for soil enviro nment. |
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