板栗空苞的发生有地区性，发生严重的地区年年都很严重，特别是嫁接树有时成片形成“空苞”。据调查，板栗正常生长的地区平均有15％的空苞率，不少地区空苞率占50％以上，严重的山坡地空苞率达叨％。土壤缺硼是引起极采产生空苞的主要原因。用是板栗受精过程中必要的元素，缺? The occurrence of chestnut empty bracts are regional, serious areas are very serious year after year, especially the grafting of trees sometimes become “empty bracts.” According to the survey, the average growth rate of chestnut areas is 15% of the average rate of empty shell, in many areas accounted for more than 50% of the empty shell, on the serious hillsides, the rate of empty shelves reached 40%. The lack of boron in the soil is the main reason causing the spongy buds. Chestnut is used in the process of fertilization of the necessary elements, missing?