Analysis of Precipitation Change Trend during Flue-cured Tobacco Growth Period in Lijiang

Based on the precipitation data from 1959 to 2009 in Lijiang, linear trend equation and regression trendliness models were used to estimate the characteristics and change trend of precipitation during the growth period of flue-cured tobacco. The results showed that the precipitation variability was big among years and growth stages of flue-cured tobacco in the areas, while the precipitation in the most years could meet water requirements of flue-cured tobacco. The mean of precipitation is 760.61mm during the growth period of flue-cured tobacco According to the simulations, the precipitation during the growth period of flue-cured tobacco in Lijiang appeared to have remarkable difference, where a clearly downward tendency from northeast to southwest could be seen. In the last 51 years, the precipitation during transplanting to maturation stages of flue-cured tobacco showed inverted S-shaped curve in a 10-year cycle. The preliminary forecasted that precipitation decreasing trend during transplanting to resettling growth stage and precipitation increasing trend during vigorous to maturation stage from 2010 to 2020.