| Disease investigations were conducted in Cao village, Shijing village, Xuan village, Mujiao village, Lingjiao Agricultural Ecological Garden in Guangxi. Eight diseases including sclerotium blight, anthracnose, dieback, top blight, leaf spot, smoke mildew, yellow ringspot mosaic and witche's broom were recorded. The causal agent of witche's broom was still unknown. Yellow ringspot mosaic was caused by virus, the other six fungi.Biological characteristics of Sclerotium rolfsii were studied. The results showed that sucrose was optimum C source and KNO3 optimum N source for its growth. Temperatures ranged from 28 to 34℃ were optimum for sclerotium germination. While 28℃ was optimum for hypha growth. Optimum pH for hypha growth was 5.0 to 6.0 and 4.0 to 6.0 for sclerotium germination. Dark condition promoted hypha growth. Light and high RH were beneficial to sclerotium germination. The study also indicated that the fungicides, such as tebuconazole, propiconazole, myclobutanil, frowncide and flusicazole, gave strong fungistatic action against Sclerotium rolfsii in vitro. The rate of inhibition to the mycelial growth all recorded 100%, and the diameter of inhibition zone 25.2mm, 18.33mm, 17.45mm, 14.01mm, 11.65 mm respectively.Antagonistic fungus G, antagonistic bacterium B and fungicide frowncide were used for management of sclerotium blight in greenhouse. The disease incidence and development were significantly delayed by the antagonistic microbes and frowncide. Treatment with antagonist G and frowncide exerted maximum control effect(46.70%) 30d after inoculation. While no significant difference of control efficacy among different treatments was recorded.Frowncide was also used to control sclerotium blight in field. |
