Abstract:

To provide certain reference on mulberry pruning in winter, we analyzed the effect of different pruning heights in winter on the yield of mulberry leaves, the number of mulberry branches and leaves, and crude protein content and water content of mulberry leaves in spring. Five different pruning heights (5, 25, 45, 65 and 85 cm) were set in winter management period of mulberry garden by random design, and the local cutting height of 5 cm was the control. After pruning for 60 days and before feeding the silkworms, the yield of mulberry leaves, the number of branches and mulberry leaves, the length of branches, stem diameter, and the water content, ash content and protein content of leaves were measured. With the increase of pruning height, the aboveground morphological indexes of mulberry, such as the yield of mulberry leaves, the length of branches, the number of mulberry leaves and stem diameter first increased and then decreased. When the pruning height was 45 cm, the yield of mulberry leaves was the highest, and the number of branches increased with the winter pruning height. According to the regression curve (R²=0.945) between the yield of mulberry leaves and the pruning height in winter, the yield of mulberry leaves was the highest when the pruning height was 45.29 cm. The correlation analysis showed that, except the number of branches and leaves, there was a significant correlation between the aboveground morphology and the pruning height (P<0.05 or P<0.01). However, there was a negative correlation between the number of branches and leaves and the diameter of stems. With the increase of the pruning height, the water content and crude protein content of leaves at lower and upper position increased first and then decreased. When the pruning height was 45 cm, the water content and crude protein content of leaves were higher compared with those of control, while the ash content of leaves increased with the pruning height. Different pruning heights in winter have a significant effect on the leaf yield and aboveground morphology of mulberry. When the pruning height is 45 cm, the yield and nutritional quality of mulberry leaves are the best.

Key words: mulberry, winter pruning, mulberry leaves, yield, quality