板栗树上挂有象刺猬一样的球果,植物学上叫总苞,又叫栗棚,球果中一般有2—3个栗子,但是有的球果里也许没有栗子,形成空棚。产生空棚的比例在燕山一带约占15%,个别地区能占一半以上,严重影响板栗的产量。产生空棚的原因,以前一般认为是综合因子的作用,其中尤以授粉和营养不良为主。为此,我们做了试验,采取人工授粉, Chestnut tree hung like a hedgehog cones, botany called involucre, also known as chestnut shed, cones generally 2-3 chestnuts, but some cones may not have chestnuts, the formation of empty shed. The proportion of empty sheds accounts for about 15% of the total area in Yanshan and more than half in some areas, seriously affecting the yield of chestnuts. The reason for creating a shed, previously considered a comprehensive factor, especially pollination and malnutrition. To this end, we did a trial, artificial pollination,