Effect of stumping on the sprouting ability of Pinus yunnanensis with different seedling ages

To discuss the response of different seedling ages of Pinus yunnanensis to the sprouting ability after stumping, P. yunnanensis seedlings aged 6 months, 10 months, 14 months, 18 months, and 30 months were flattened to obtain 5 treatments in this study. The cumulative number of sprouts, net number of sprouts, and sprout length were measured, and the response of their sprouting ability was analyzed every month from 30 days after stumping.

Results The results showed that the cumulative number of sprouts of P. yunnanensis seedlings with different seedling ages after stumping followed a logistic growth process, increasing with the increase of seedling age. The fast-growing point of M6, M10, M14 and M18 were close and appeared in 60 days after stumping, while the fast-growing point of M30 appeared in 116 days after stumping. The number of net sprouts showed a trend of first increasing and then decreasing with growth time, tending to be gentle. Except for M30, the number of net sprouts reached its maximum value 30 days after stumping, and M30 reached its maximum value 180 days after stumping. The number of effective sprouts in 240 days after stumping accounted for the largest proportion in M6 and M30, but the survival rate of M30 was only 20.75%, and the cultivation time was longer. The number of effective sprouts in M10, M14 and M18 increased but in much lower numbers than in M6 and M30 after stumping.

Conclusion The experimental results indicate that different seedling ages of P. yunnanensis have different responses to the sprouting ability after stumping. The cumulative number of sprouts was lower in M6 than in M30, but the survival rate of female plants in M6 through M18 was 80%, which was much higher than that in M30. Therefore, stumping at 6 months of seedling cultivation has the better effect and can obtain high-quality sprouts.