一、生产实践中出题目一九七四年五、六月间,我分场大量地引种加勒比松(洪都拉斯变种)、湿地松和火炬松,但种植后不久,到大署小署间,幼苗针叶变黄发紫。加勒比松和火炬松大量死亡,成活率仅分别为0.5%和3%。湿地松成活率虽有70%,但第一年几乎停止了生长。为什么会有此损失呢?当时说法不一,我们科研组都逐一进行探索,其中有一条认为由于没有菌根,看 I. Problems in Production Practices In May and June of 1974, I introduced a large number of Caribbean pine (Honduras varieties), Pinus elliottii and Pinus pine under our sub-program, but shortly after planting, Needle yellowish purple. A large number of carp pine and loblolly pine death, survival rates were only 0.5% and 3%. Although the survival rate of slash pine 70%, but the first year almost stopped growing. Why did this loss? At that time, different opinions were used, and all of our research groups went one by one to explore. One of them considered that because there is no mycorrhizal,