A Preparation Of 30% Propiconazole+Difenoconazole Se And Extention To Control Wheat Sharp Eyespot And Rice Sheath Blight

Wheat sharp eyespot is one of important rice diseases in China. Validamycin, carbendazim, triadimefon are widely used to control this disease. Owing to applying these fungicides for many years, and the control effect decreased greatly. This paper is to developed 30% propiconazole+difenoconazole SE to control the diseases of wheat and rice.1. Rhizoctonia cerealis against 12 fungicides was evaluated by mycelial inhibitive assay in vitro. The results indicated that difenoconazol had the best inhibitive efficiency on the mycelial growth (EC50=0.67μg/mL). The second best inhibitive efficiency was propiconazole with the EC50 1.08μg/mL. The synergism of difenoconazol and propiconazole were tested by bio-assays employing Rhizoctonia cerealis. The co-toxicity coefficients (CTC) of propiconazole+difenoconazole in different ratios varied from 115.64 to 194.78, showing a additive or synergistic effects, the most perfect ratio of difenoconazol and propiconazole was 1:1, the EC50 was 0.42μg/mL.This ratio of could be chosen as the prescription of compound.2. In order to develop an environmental friendly formulae,30% propiconazole+difenoconazole Suspension emulsions(SE) was determined. The optimal composition was propiconazol 15%, carbendazim 15%, sodium methylene bis-naphthalene sulfonate 1.5%, soprophor HY-22.5%, dimethylbenzene 5%, calcium dodecylbenzene sulfonate 1.5%, emulsifier 331.5%, phosphate ester 1.5%, sulfonation 0.5%, magnesium aluminosilicate 2.0%, xanthan gum 0.5%, ethylene glycol 4.0%, octanol 0.5% and water 53% were determined. The experimental results showed all indexes of the formulae were qualified to the requirements for the formulation.3. Under the study on wavelength, mobile phase, linearity correlation and accuracy of quantitative analysis of 30% propiconazole+difenoconazole SE by Gas Chromatography, a method of detect contents of propiconazole and difenoconazole in compound of SE was introduced. Test results shows, under the same condition, the two effective componets among propiconazole+difenoconazole SE separated obviously, with keeping times were 10.2 min and 2.3 min respectively. This method was convenience, quickness, high accuracy, and could be used as the analysis method of 30% propiconazole+difenoconazole SE.4. Field trials of 30% propiconazole+difenoconazole SE to wheat sharp eyespot and rice sheath blight had been evaluaed at four different province of Jiangsu, Shandong, Henan and Anhui from 2006 to 2007. The results showed that the formulae could control the two diseases, effectively. With the doses of 15 to 20 mL per 667m2, the control efficiency to wheat sharp eyespot varied from 67.8% to 82.74% with mean efficiency of 81.8%, while control efficiency to rice sheath blight varied from 64.44% to 84.52% with mean efficiency of 82.9%. During the period of 2007-2008, this foumulae had been applied about 200000 ha with the mean control efficiency of about 85%.