Abstract:

Abstract: The genotypes of forest trees and the optimum mixture ratio for fertilization are crucial factors for breeding superior seedlings. In this experiment, seven half-sib families were selected for the culture of Betula platyphylla seedlings. During the growth period, three different nutrient solutions, with different mixture ratios of N.P.K, were used to fertilize the seedlings on the leaf surface regularly. Hitherto, this paper for the first time reported a systematical study of the effects of the formula fertilizer on different families of Betula platyphylla, which could provide theoretical bases for breeding superior seedlings with higher survival rate after being transferred from the nursery. After the variance analysis and multiple comparisons of several indexes, including the height and height to caliper ratio and shoot to root ratio, of each families under three different fertilization treatment as well as control, we found the optimum fertilizer prescription for each family. The results were as follows: the optimum fertilizer prescription for F1, F3, F4, F5 was T2, promoting the seedling height by 13.43%～35.74%; the best fertilization prescription for F6, F7 was T3 which was able to enhance the seedling height by 24.93% and 26.46%; and the optimum fertilizer prescription for F2 was T1. The three fertilizer prescription all improved the growth during the seedling period. As for the seven families as a general, T2 was the best fertilizer prescription.

Key words: Key words: Betula platyphylla family, prescription fertilization, seedling growth