磷肥对不同结实能力马尾松无性系雌球花量及针叶氮磷营养的影响

为实现马尾松无性系种子园精准施肥和丰产经营,用不同结实能力无性系作为材料,设置每株0、400、800和1600 g 4个磷肥水平(分别记为Po、P4、P8和P16),分别在花原基形成前和球果采摘后施肥,研究磷肥对马尾松无性系雌球花量的影响,以及花原基形成期和球花分化前期不同高度的针叶N、P含量的变化.结果 表明:与Po...

Effects of P fertilizer on female strobilus and needle N and P nutrition of Pinus massoniana clones with different fruiting abilities.

In order to realize precise fertilization and high yield management of Pinus massoniana clonal seed orchard, clones with different fruiting abilities were used as the materials. Four P fertilization levels were at 0, 400, 800 and 1600 g per plant (P₀, P₄, P₈ and P₁₆ respectively). Fertilization was applied before floral primordia formation and after cone picked, respectively. The effects of P fertilizer on the female strobilus of P. massoniana clones and the changes of N, P contents in needles of different positions during floral primordia formation stage and early stage of flower bud differentiation were investigated. The results showed that compared with P₀, the female strobilus of P₈ and P₁₆ were significantly increased by 67.4% and 61.2% in 2018 and 28.9% and 14.1% in 2019, respectively. There was a significant negative correlation between the female strobilus with the N content and N/P, a significant positive correlation between the female strobilus and the P content in needles. The responses of N and P contents in needles to P fertilization differed in clones with different fruiting abilities. In floral primordia formation stage, the N content of clones with weak fruiting ability was high, and the N/P was 11.5-12.5, while the P content of clones with strong fruiting abilities was high, and the N/P was 9.5-10.5. During this period, the P content of most clones under P₈ treatment was the highest, while the N/P was lowest. In the early stage of flower bud differentiation, the N/P of two fruiting clones was 15.3-17.0 and 13.2-15.1, respectively. The P content in upside layer was significantly higher while N/P was significantly lower than that in middle and lower layers. In conclusion, the 800 g P fertilization per plant could increase the P content and reduce the N/P of needles during the floral primordia formation stage of clones with diffe-rent fruiting abilities, which was beneficial to the formation of female strobilus and promote the yield of clone seed orchards.