Effects of different concentrations of paclobutrazol on growth，yield and quality of sunflower

In order to study the effects of paclobutrazol on the growth，yield and quality of sunflower，different concentrations of paclobutrazol（50，75，100，125，150 mg/L）were sprayed on the leaves of sunflower. The results showed that paclobutrazol treatment had different degrees of inhibition on sunflower plant height，increased the sunflower stem diameter，shortened the sunflower internode length and petiole，reduced the sunflower leaf length and width， decreased the leaf number，increased the sunflower plate diameter，single plate grain weight and hundred grain weight， increased the rate of seed kernels，increased yield，at the same time could improve the quality of sunflower seeds， improve the grain crude protein and crude fat content and so on. The results indicated that sunflower sprayed by 75 mg/L of paclobutrazol performed best.