Studies On Biological Characteristics Of Neovossia Horrida And Control Of Fungicides To The Rice Kernel Smut

Rice kernel smut is a kind of common disease on hybrid rice which is causedby Neovossia horrida fungus.Because its damage on rice was not serious inconventional rice, its controlling methods and fungicides about the disease haveseldom been studied. Along with the spread of hybrid rice, it has become an importantdisease in hybrid rice seed production and has affected its yield and the qualityseriously, thus hindering the hybrid rice from a further advancement. So far, therehave been few fungicides and formulations which can effectively control the disease.By studying preliminarily the biological characteristics of Neovossia horrida,screening experiment of controlling fungicides on rice kernel smut and surfactant, theresults are as fallows.1. Studies on biological characteristics of Neovossia horrida indicate that thegermination of the chlamydospores is not at the same pace, the germination of thechlamydospores lasts more than 60 days, and some chlamydospores can germinatewithout dormancy.2. In the field trials, two formulations, Propiconazole-Di-fenoconazole 30% EC andTebuconazole 25% EW have been screened. They are. Their effects on Rice kernelsmut are 86.8% and 81.4% respectively.3. A new employing technology of pesticide was studied and a new proposition offormulation carbendazim surface-agent model was raised by using the 0~# diesel oil asdispersion medium. This method can prevent the chlamydospore from germinatingand its spreading effectively. Also it can control the expanding of the germ and reducethe diseased seed rate greatly. Its controlling effect using Folicure spray is 77.81%,17.9 percent higher than that of other formulations and application. By contrast withthe traditional using methods, the new formulation can reduce the labor intensityeffectively, and enhance the labor productivity greatly, with better controlling effect.