Study On Regularity Of Occurrence And Chemical Control Of Corm Rot Of Chinese Water Chestnut In Store Period

dominant pathogen and Trichoderma asperellum was the second dominant pathogen. When temperature in storage was 25℃or room temperature (16.4-30.0℃), Trichoderma asperellum was the first dominant pathogen and Fusarium oxysporum was the second dominant pathogen.It was showed that incidence of corm rot of Chinese water chestnut was lower if temperature in storage was 20-25℃and was higher if temperature in storage was 10-20℃. If corm pile was between 50-70 cm height in storage, incidence of corm rot of Chinese water chestnut were not obviously different. Corm rot of Chinese water chestnut were also not obviously different between corms with red-leaf disease and with no red-leaf disease at growth stage.The forecast formula was established based on store period (x₁) and average temperature (x₂) per ten-day as self-variable, and incidence (y) of corm rot of Chinese water chestnut as dependent variable.(?) =24.70+0.21 x₁-1.04 x₂ was established based on incidence of corm rot under natural store condition, (?) = - 9.26 + 0.20 x₁+0.46 x₂ was established based on incidence of corm rot with spraying fungicide before storing and no picking rotten corms out, and (?) =4.88+0.15 x₁- 0.11 x₂ was established based on incidence of corm rot with spraying fungicide before storing and picking rotten corms out per ten-day in store period. The fitness of forecast formula was considerable.The fungicides of thiabendazole+iprodione, propiconazole, prochlorraz, and prochlorraz+iprodione could decrease incidence of corm rot of Chinese water chestnut in storage and control efficacy of thiabendazole+iprodione and prochlorraz+iprodione were the best among them. Eleven species of pathogens which were isolated from 4 710 samples of corm rot of Chinese water chestnut successively collected from storages of 4 places including Qingshan Town of Lipu County, Liantang Town of Babu Region, Yuantou Town of Pingle County and Guangxi University in Guangxi were identified as Trichoderma asperellum, Fusarium oxysporum, Penicillium sp., Fusarium sp., Trichoderma aureoviride, Trichoderma atroviride, Trichoderma viride, Mucor sp., Zygorhynchus sp., Thielaviopsis sp., Nectria sp. and isolation rates of these 11 species were 36.8%, 32.9%, 7.5%, 4.3%, 3.9%, 3.1%, 3.1%, 2.7%, 2.6%, 2.5%, and 0.5%, respectively. Trichoderma asperellum and Fusarium oxysporum, which isolation rates were the highest among them, were dominant pathogens of corm rot of Chinese water chestnut in storage. Trichoderma aureoviride, Trichoderma atroviride and Nectria sp. were first recorded as pathogens of corm rot of Chinese water chestnut in storage.The temperature in storage influenced the species of dominant pathogens. When temperature in storage was 15-20℃, Fusarium oxysporum was the first...