Epidemic Research Of Grey Mould Disease On Strawberry And Tomato Greenhouses Of Hubei Province

Grey mould caused by Botrytis cinerea is one of the important diseases on greenhouse fruits and vegetables, which results in flowers and fruits rot, and seriously affects the yield and quality of greenhouse fruits and vegetables. Due to the particular environment of greenhouse, grey mould always leads to devastating loss once it happens. The control of greenhouse strawberry and tomato grey mould relies mainly on chemical method and the control of greenhouse temperature and humidity against Botrytis cinerea. Also, the disease control effect is closely related to the time and method of chemical control. Therefore, the influence of greenhouse temperature and humidity on the incidence of strawberry and tomato grey mould in Hubei province was studied, and the control of strawberry grey mould was discussed in this paper.Comprehensive epidemic results of greenhouse strawberry grey mould occurred in 2013 and 2014 were as follows, the flowers grey mould started from last December, peaked in the mid to late March and April to early May, the average incidence was 8.09%, the peak incidence was 31.81%;The blade grey mould began in early January with no obvious peak, the average incidence is 0.62%;The fruit grey mould began in late December, peaked in the mid to late March and April, the average incidence was 9.86%, the peak incidence was 86.07%. The greenhouse temperature and humidity of two years were consistent, the average daily temperature was 6 ~ 23 ℃, relative humidity 63 ~ 90%. Optimum temperature(20 ℃ < T < 25 ℃) and high humidity(RH > 85%) were beneficial to the occurrence of strawberry grey mould, and low temperature(T < 10 ℃) inhibited the incidence. The correlation between greenhouse temperature and humidity and strawberry grey mould incidence was studied in two years, integrated analysis showed that, strawberry grey mould incidence was no significant correlation with relative humidity of greenhouse, and disease incidence of strawberry flower, leaf and fruit were significantly positive correlation with temperature(p < 0.05), the disease incidence of leaf and fruit were significant correlation with disease rate of flower, which showed that flower infection played an important role in the whole strawberry grey mould epidemic. Strawberry carrier rate were studied by moisturizing and PCR detection method, PCR detection results were more stable, the comprehensive results were as follows, strawberry flower, leaf and fruit with Botrytis cinerea were detected from late December, flowers carrier rate peaked in late December and mid of March and April, the average carrier rate was 10%, the peak rate was 50%; Blade carrier rate peaked in mid to late January and late March, the average carrier rate was 9.26%, the peak carrier rate was 50%. Three chemical of different concentrations were studied to control greenhouse strawberry grey mould, the results showed that continuous spray twice of the same concentration and the same drug controlled better than once, 0.4 g/L Pyrimethanil suspension had best control effect, 0.33 g/L Boscalid the lowest, the control effects of continuous spray twice of them were respectively 71.67% and 56%.Comprehensive epidemic results of greenhouse tomato grey mould in 2013 and 2014 were as follows, the flowers grey mould started from last March, peaked in late May, the average incidence was 7.12%, the peak incidence was 23.82%; the stem grey mould started from last March, peaked in late May, the average incidence was 4.46%, the peak incidence was 14.37%;The blade grey mould began in early March with no obvious peak, the average incidence is 4.46%;The fruit grey mould began in last March, peaked in the mid to late May, the average incidence was 1.29%, the peak incidence was 11.17%. The greenhouse temperature and humidity of two years were consistent, the average daily temperature was 13~31 ℃, relative humidity 71 ~ 95%. Optimum temperature(20 ℃ < T < 25 ℃) and high humidity(RH > 85%) was beneficial to the occurrence of tomato grey mould. The correlation between greenhouse temperature and humidity and tomato grey mould incidence was studied in two years, integrated analysis showed that, tomato grey mould incidence was no significant correlation with relative humidity of greenhouse, and disease incidence of tomato flower was no significant correlation with temperature, disease incidence of leaf and fruit were significantly positive with temperature and disease rate of flower(p < 0.05), the disease incidence of fruit were significantly correlation with disease rate of leaf,(p<0.01),Y=4.857 X-0.432(R2=0.91). Tomato carrier rate were studied by moisturizing and PCR detection method, PCR detection were more sensitive in detecting Botrytis cinerea on tomato flower, the comprehensive results were as follows, tomato flower and leaf with Botrytis cinerea were detected respectively from mid to late April and early March, flowers carrier rate peaked in mid to late April and May, the average carrier rate by PCR detection was 75.70%, the peak rate was 100%; Blade carrier rate peaked in mid to late April and May, the average carrier rate was 27.33%, the peak carrier rate was 81.25%. The survival of diseased tomato tissues under different soil depths showed that, on the soil surface, Botrytis cinerea on tomato stem and leaf can live for 60 d and 30 d respectively; Under the soil 10 cm, Botrytis cinerea on stem and leaf can both live for 30 d. In soil depth of 20 cm, Botrytis cinerea on stem can live for 30 d, gray mold on the leaf could not live.