Effects of uniconazole on the drought resistance of Perennial ryegrass

The effects of uniconazole (S3307) on the drought resistance of Perennial ryegrass were investigated by pot experiment under different concentration treatments of SS3307（0-80 mg/L）. Perennial ryegrass was subjected to soil drought stress by withholding watering at the fifteen days after spraying SS3307. The results showed that S3307 increased the relative water content of Perennial ryegrass and therefore increased the drought resistance. When the soil water content decreased to 14%, the leaves of nonspraying control withered greatly, however, the leaves in uniconazole treatment had normal leaf color, the contents of chlorophyll, the leaf water content and freeproline, and also the ratio of the root to crown of Perennial ryegrass were significantly increased, the treatment with 40 mg/L concentration were better than others. When the concentration increased to 80 mg/L, it restrained the growth of underground part, and decreased the range and depth of imbibing ability, then reduced the resistance of the Perennial ryegrass. This suggested that spraying 40 mg/L uniconazole could effectively increase the drought resistance of the Perennial ryegrass.