Effect Of Meteorological Factors On Wheat Stripe Rust And Wheat Scab In Hu County

Wheat is an important crop worldwide, but many of the wheat disease not only affect the yield of wheat, also have an impact on the quality of wheat. In the Guanzhong area,wheat stripe rust and wheat scab are two relatively common major wheat diseases. At the same time, these two diseases are also well known as they are greatly influenced by weather conditions. In view of this, the present study took Hu county as an example and used gray correlation analysis and sensitivity analysis to deal with the data of meteorological factors and the corresponding data of wheat diseases, the main conclusions are as follows:(1)In terms of wheat strip rust, firstly, the result showed that the wheat strip rust pathogen can survive over the winter but not the summer in Hu County. In the second place, the amount of disease field area of wheat stripe rust fluctuated from 1998 to 2012 in Hu County and the biggest amount of disease field area happened in 2005 with 2.8×104 hm2. Besides, the grey comprehensive correlation of meteorological factors and field disease rates of wheat stripe rust and analysis results of different meteorological factors showed that factors associated with grey comprehensive correlation greater than 0.6, including the spring epidemic average relative humidity R7(0.669) and spring epidemic precipitation R6(0.622), were the main meteorological factors impacting the development of wheat stripe rust in Hu County and they can be used to predict the occurrence of wheat stripe rust situation in Hu County. Finally, the grey relative correlation of the average temperature over January(R4), precipitation over spring epidemic stage( R6) and the average temperature over autumn-seedling stage(R1) were 0.604, 0.588 and 0.557, respectively. As a result, the fluctuation rates of all of these three meteorological factors can be used to predict the fluctuation situation of the field disease rates of wheat stripe rust in Hu County.(2)In terms of wheat scab, firstly, the results showed that the incidence of wheat scab in Hu County had a significant increase trend and fluctuated dramatically over the 15 years and the worst year was 2010 with 100 percentage disease fields. Secondly, factors associated with grey correlation greater than 0.75, including the heading and flowering average relative humidity R2(0.902) and autumn precipitation R6(0.805) and the heading and flowering precipitation R1(0.757), were the main meteorological factors impacting the development of wheat scab in Hu County. Additionally, the average relative humidity(R2) and precipitation(R1) over the heading-flowering stage can be used to predict the occurrence of wheat scab situation in Hu County. In addition, combining the data of absolute of gray incidence, the average relative humidity over heading and flowering stage R2 and the precipitation over heading and flowering stage R1 can be used to predict the future situation of wheat scab. Meanwhile, combining the data of gray relative relationship and precipitation over autumn R6, heading and flowering average relative humidity R2 and sunshine hours over heading and flowering stage R4 can be used to predict the onset of fluctuations in the area of wheat scab in terms of fluctuation rates.(3) Between 1998-2012, except the sensitivity between the average temperature in the winter and the disease rate of wheat stripe rust in Hu County rising, all the other meteorological factors had a downward sensitivity with the disease rate of wheat stripe rust and all these five sensitivity were in close proximity. Except the sensitivity between the precipitation in autumn and the disease rate of wheat scab in Hu County decreasing, all the other meteorological factors had a upward sensitivity with the disease rate of wheat scab. Especially the sensitivity between the temperature in winter and the disease rate of wheat scab is higher than other five meteorological factors’ sensitivity.