Study On Regularity Of Plasmopara Viticola Causing Grape Downy Mildew And Disease Control In Shihezi Region

Through carrying grape downy mildew cutting branches and carrying pathogen debris overwintering testing, it was preliminary found that in the areas of ShiHezi the Plasmopara viticola could not overwinter by cuttage gleization hyphal branches to bud in the winter.It was largely based on oospore on the carrying pathogen debris or in the soil to overwinter.Incidence of the law through the study of the identification of Plasmopara viticola sporangia could germinate in 10-35℃to 23℃the highest germination rate. After inoculation by the 12-48h moisture, it could be got disease, the moisture longer, the higher the incidence of disease was also more serious.,between the annual incidence of significant differences, it mainly related to rainfall in the month 6-8, relative humidity and temperature, especially for rainy, cold weather, could easily result in the outbreak and spread of disease.Observation of the spores amount in field was carried out through the spores capturer, combined with disease investigation and analysis of meteorological data, it was definited that within 24 hours in the day, the spores amount during the day was more than at night, sporangia during the day to 8:00 and 20 was more arrested and more stable, further more the suitable height for setting the spores capturer was found to be 2 to 2.5meters.Investigation and testing shows that during the whole date of grape downy mildew incidence, the disease increasing index were correlation to the spores amount. Downy mildew reported in the literature a large number of the latent period of 4 days, with our field survey, and inoculation test results were consistent. Field captured sporulation 4 days after a surge in patients could see significant expansion of law may capture spore forecast four days in advance to predict the disease in order to achieve the system early, by the numbers of the capturing-spores ,we could predict the development of disease,prevention and treatment of small government and effective to reduce economic losses.Through the identification of disease resistance and field surveys indoor and outdoor, it was demonstrated that the different varieties of grape had significant differences on their resistance. Through investigating of the leaves resistance identification, 33 varieties of causing grape to grape downy mildew disease could be divided into four category in ShiHezi, showed that the resistance of first type cultivars was stronger, including JingYa,KeRuisen, Folei , GaoQi, XinNongle, BaiXiangjiao, the disease-index range was from 9.31 to 19.27. The resistance of second type cultivars was medium, including 8611, HuangJiaqiutian and so on .The third type cultivars were susceptible, including HeiDali, AoDiyawuhe and other ten cultivars. The fourth type was most susceptible variety including WuHezi and other 5 cultivars, which disease-index was all above 64.Results of the effect of the tested pesticides in plate and in field indicated that for the test in 66.8%MelodyDuo,70%Antracol,78%Cuprofix was not only for Plasmopara viticola sporangia germination significantly inhibited, while the disease is also more apparent protective effect of prophylactic and therapeutic effects. Auken SC,72% Cymoxanil mancozeb WP, 35% Dimethomorph WP, 50% Upone WG was also had good effect. Protection in the pharmaceutical trials, the protective effect of Bordeaux mixture was still prominent, the focus should be to promote the use of the protective agent.