久树引种到云南干热河谷区能正常生长和开花结实,其植株开花率约30%,19 2%开雄花,10 8%开杂性花;风媒为主;花期主要集中在每年3月中旬至4月上旬;结果率为开花数的39 9%,存果率仅为开花数的6 3%,大量落花落果的主要原因是3—4月的河谷大风和雨季初期的大风降雨;在元江河谷区于7月下旬至8月初可采种,其它地方稍晚。久树种子育苗需对种皮进行处理,机械破壳是目前最简便、经济和有效的方法,育苗地要选择光照和通风好的地方。 Long trees introduced to dry and hot valley in Yunnan Province to normal growth and flowering and fruiting, the flowering rate of about 30% of its plants, 19 2% open male flowers, 108% open hybrid flowers; wind mainly; flowering mainly in March each year From mid-April to early April, the result rate was 39 9% of the flowering and fruit-bearing rate was only 63% of the flowering. The main reason for the large drop-off was the wind gale in March-April and the heavy rain in the early rainy season. Yuanjiang River Valley in late July to early August can be planted, other places later. Long seed tree seedlings need to be dealt with the seed coat, mechanical breaking the shell is the most convenient, economical and effective way to nursery to choose a good place for light and ventilation.