Study On The Resistance Evaluation Of Main Flue-cured Tobacco In Kunming To Tobacco Disease And Its Occurrence Tendency

To identify elite gene resource resistant to tobacco black shank (Phytophthora parasitica var. nicotianae), tobacco mosaic virus and tobacco brown spot disease in the cuhivar'hongda','K326','yun87'species, three species were tested in natural field test garden to select materials resistant to these tobacco disease. Results showed that the integrative disease resistance of various cuhivar:K326>yun87>hongda. Respectively, the cuhivar resistance to Phytophthora parasitica var.nicotianae:K326>yun87>hongda, the cuhivar resistance to tobacco mosaic virus:hongda>yun87>K326, the cuhivar resistance to tobacco brown spot:K326>hongda>yun87.The investigation on the diseases and pest insects was carried out in the main distribution and cultivation area of three counties (Luquan county, Fumin county, Yiliang county) in Kunming city. The results showed that tobacco black shank disease occurs mainly in June and July period, easily affected by rain, under the high-moisture burning hot weather easy to have plant disease. Specially, the adjacent periods which grows in the tobacco have the occurrence, by tobacco mosaic virus primarily, the symptoms is the appearance "the arteries is bright", the leaf blade assumes the olivine interaction the heterogeneity. The cuhivar K326 growth earlier period occurrence in field, the floral leaf is mainly obvious, however, the cuhivar K326 mainly occurs growth later period in the field. The tobacco brown spot disease occurs when the leaf tobacco enters is mature starts to be taken bad, the morbidity degree aggravates gradually along with the leaf tobacco mature plant disease, The temperature and the humidity are affect it to have the degree primary factor. Often with tobacco wildfire disease mix occurrences. The tobacco wildfire disease occurs mainly in June Tuanke-period of tobacco in the field and July period, The symptoms degree and the'low atmospheric pressure, the high-moisture and the illumination are insufficient the meteorological factor has the close relation.The tobacco anthracnose disease occurrence growth period of tobacco in the field. The symptom peak was mainly at the end of June to the beginning of August.