| Rice is the main food crop for people. The yield and quality of rice are mainly concerned for a long time. Thence, the rice crop loss caused by diseases and pests are the problems that people had been researching and solving. Rice rtalk rot sclerotia is one of the important diseases on rice production. The influence of the environment such as the acid, alkaline soil, climatic conditions, made the disease severity different. In the past, the disease mostly occured in the Yangtze river, Southwest and Southeast of rice planting areas, etc. But in recent years, in Jilin and Heilongjiang, the disease not only had occurred, but also trended to gradually expand and aggravate the harm degree. Therefore, it was great significant and valuable for the production to prevent the treatment of rice Sclerotium stalk rot in life. In this study the sclerotium of rice stalk rot control and the resistance of varieties were investigatived to effectively control sclerotium rice stalk rot. The results of the study were as follows:1、To determine the optimum growth environmental combination factors to sclerotium rice stalk rot hypha, three factors orthogonal experiment was carried out about light, temperature and medium. It choosed the optimal combination to understand the different environmental factors’ effect on the rice stalk rot sclerotia. The out comes indicated that the temperature was the strongest factor. The second was the light and the last was the culture medium. The most suitable environment conditions for mycelial growth were 30℃, dark and PDA culture.2、The resistance research of the 17 kinds of rice cultivars to rice stalk rot was conducted. The living potted inoculation technology was used and observed the disease incidence of different cultivars. According the grading and resistance standard to calculate the incidence and disease index. The results showed that Jijing88 and 9903 had stronger resistance than other cultivars to Sclerotia rice stalk rotdisease. For this reason that Jijing 88 and 9903 can be used widely in production.3、This research aims to test the indoor toxicities of several kinds effective fungicides and screen out the proportioning ratio for controlling rice sclerotium stem rot, and lay the foundation for the next agent distribution work. Boscalid, coumoxystrobin, kresoxim and hymexazol had good inhibitory effect with EC50 of 0.0037 mg/L、0.0079 mg/L、0.0091 mg/L、0.0096 mg/L, which were all under 0.01 mg/L.4、Four kinds of reagents on the fungi had best inhibition effects. In the light of the single dose indoor toxicity measurement, a single dose of bacteriostatic effect which was good was choosed. In line with the different organism mechanisms, boscalid, coumoxystrobin, kresoxim and hymexazol were mixed. At the same time in order to verify the control effect, the examination was advanced by outdoor potted experiments. The results revealed that when boscalid and coumoxystrobin were blended at ratio of 5:1, the synergy was strongest with synergistic coefficient of 6.28. It also achieved better synergy in the pot experiment with the efficiency coefficient of 5.11.5、On the basis of the distribution of medicament,the process researched drug for the water dispersible granule of 36% by liquid chromatograph analysis of the drug. The drug contained 30% boscalid, 6% coumoxystrobin, 4% Sodium dodecyl sulfate, 2% Sodium lignosulphonate, 2% urea and diluted kaolin up to 100%.6、Under the research results of pharmacy compounding of boscalid and coumoxystrobin, the field control effect experiments were launched. Field efficacy results demonstrated that when the indoor 36% boscalid·coumoxystrobin WDG was used at the dosage of 200 g.a.i./hm2, after 3 times of drug control effect after repeated trials, the average control effect to this rice stalk rot sclerotia reached 90.84%. It provides a new reagentselection for the prevention and treatment of the rice stalk rot sclerotia in field. |
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