| Flase smut of rice(FSR), Uiilagidea viwia (Cke)Tak, is widely dispersed over the world and a widespread disease in the major of rice planting area of China. Since it was first report in Wuchang city of Hdiongjiang province in 1986, it has spreaded to more than 10 counties in the southern region of province and aggravated the yield loss of rice gradually. The objective of the present paper was to study the biological characteristic of Uo~ilagMoidea vwena (Cke)Tak, the ocQurrence of FSR, yield loss of rice damage by FSR and its control techniques. 1. Using FSR sclerotia isolation to culture pathogen of FSR In PSA medium, the study demonstrated that the best C source for mycellium growth was sucrose, the suitable concen- tration was ranged from 254?54 ,the suitable temperature was 25~C, it was conducive to myceuium growth in dark condition. The soaking liquid of diseased grains significantly influ- enced the germination of rice seeds, which the inhibition to germination of seeds was strong with the Increase of soaking liquid concentration. 2. The results of experiments by Inoculating pathogen of FSR at different developmental stage of rice showed that the rice boot stage was infection period of FSR. Field investigation Indicated the occurrence of FSR was related to the meteorologic condition of years, specific climate of fields, varieties - resistibility and application of fertilizer rate. When it was more precipitation, less sunshine time, higher relative humidity and suitable temperature during .lulyug. the occurrence of FSR was early, serious and7 It could be more the formation of .cclerotium. Under the condition of specified P fertilir application , the damage by FSR worsened with the increase of N fertilizer rate. 3. The study of yield loss of rice damaged by FSR showed that the number of diseased grains each diseased ear was difference, with the increase of the number of diseased grains the weight of grain each ear decreased and the blighted grain rate increased, 1000梘rain? weigh decreased and the rate of yield loss of rice increased. It was significantly positive linear correlation between the number of diseased grains and th~ rate of blighted grain per ear. 4. There were differences of incidence of the disease among rice varieties. Through 2 years field identication, the resistant varieties to FSR were identified; they were Munian No. 3, Daoguang, Longdun 90?47, Xueguang, Mu 840, Ha 97?93, Mu 19, Mu 96? 103, Dong 9601, HeJiang 23, Ji 89?5, Mu 20, Mu 22, Mu 20iao, Tongxi 103, Llzhihong, Mu 1894 and etc. The susceptible varieties were Zupei 20, 88?1, Qiutian No.2, Qingjin Pi, Ha 35013, Qingxiangnuo, Ha 92?3, Shisei, Fengjin Pia, Shijin P1 and etc. 5. The control by fungicide in the field demonstrated that the control efficiency with sprays of 304 DT 450g aiIhm or 154 triadixnefon 225g ?alIhm2 WP at rice boot stage was over 9054, which was salty to rice . Also ,the adaptation of agricultural measure, such as cleaning diseased remnants from field, could decreased the occurrence of FSR. Names Ji Hongping Speciality: Plant Pathology Advisor: Wen Jingzhi... |
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