我省栽培的板栗,自古以来习惯用播种繁殖,但由于板栗是异花授粉植物,不仅其后代单株间产量和品质的差异悬殊,而且种性混杂,良莠不齐。据调查,遵化县沙坡峪大队高产单株可达250斤,而同样的立地条件,大部分低产树只产6—8斤,甚至还有仅结栗蓬不长栗子的“哑子”树和“渣子树”。果实成熟期也不一致,最早的8月下旬成熟,最晚的要到10月下旬成熟。迁西县杨家峪大队20,121株结果树,株产在40斤以上的丰产树仅占2.7%,株产8.6斤的单株占86.1%,株产2.8斤的低产树占11.2%。为改变这种状况,我们从1971年开始,在板栗单株选优的基础上,于1973年在迁西、遵化两县的一些重点大队,对“渣子”和“哑子”等低产劣种树实行多头高接、改换优种的试验,嫁接后,2年始果,3年获一定产量。迁西县杨家峪大队22株40—50年生低产树(株产5斤以下),高接后连续4年增产, The chestnut cultivated in our province has been habitually propagated by planting since ancient times. However, because the chestnut is a cross-pollination plant, the yield and quality of the offspring are not only greatly different, but also mixed with different varieties. According to the survey, Zhahua County Shapoyu brigade up to 250 pounds of high-yielding single plant, and the same site conditions, most of the low-yielding tree produces only 6-8 kg, and even only chestnuts chestnut not long chestnut “dumb” tree And “residue tree.” Fruit ripening is inconsistent, the earliest mature in late August, the latest to mature in late October. 20,121 trees of Yangjiayu brigade in Qianxi County accounted for only 2.7% of the high-yielding trees that produced more than 40 kilograms, 86.1% of the trees that produced 8.6 kilograms, and 11.2% of the low-yield trees that produced 2.8 kilograms. In order to change this situation, we started from 1971 on the basis of selection of individual chestnut plants. In 1973, a number of key brigade groups in the two counties of Qianxi and Zunhua moved to lower-yielding and inferior species such as “Dregs” and “Dumb” Tree implementation of long high pick, replacement superior seed test, after grafting, 2 years before the fruit, 3 years have been a certain yield. Qianxi County Yangjiayu brigade 22 40-50 year-old low-yield trees (strains produced less than 5 pounds), high yield and increase for 4 consecutive years,