荔枝“大小年”结果现象及秋冬季关键技术对策建议

The Biennial Bearing in Litchi and Key Management in Autumn and Winter

利用近10年全国59个主产县的荔枝单产数据,比较分析各县区、示范园和荔枝品种的“大小年”表现。数据显示:全国荔枝平均亩产267.1千克,居平均值以上的县24个,最高650.4千克;平均大小年结果指数(BBI)为0.24,位居平均值以下的县35个,BBI最低为0.05;亩产位居平均值以下的产区县35个,平均亩产在100~150千克之间,BBI在平均值0.24以上的产区县24个。64个体系示范园荔枝的加权平均亩产量为523千克,加权平均BBI为0.33。亩产在平均值以上和BBI在平均值以下的品种包括‘白糖罂’‘妃子笑’等;单产较高但BBI也较大的品种有‘鸡嘴荔’和‘黑叶’;‘桂味’‘糯米糍’等优质品种单产低、BBI高,表现出低产和不稳产的特征。建议借鉴‘妃子笑’和‘白糖罂’的管理经验,从果园改造、充足养分管理、恰当的水分调控、严格的末次秋梢期调控、准时促花等环节入手,做好克服荔枝“大小年”生产的秋冬季技术管理。

Based on the data of litchi yield in 59 major producing counties in China in recent ten years,the biennial bearing index(BBI)was calculated in counties,demonstration orchards and cultivars.The data indicated that,the average yield per mu was 267.1 kg,and there were 24 counties with yield above the average with the maximum of 650.4 kg.The average BBI was 0.24 and there were 35 counties with BBI below the average with the minimal BBI of 0.05.On the other hand,there were 35 counties with yield below the average and their average yield was from 100 kg/mu to 150 kg/mu,and the BBI index of litchi from 24 counties was above the average of 0.24.The weighted average yield per mu was 523 kg while the weighted average BBI was 0.33 in the 64 demonstration orchards.Cultivars'Baitangying','Feizixiao','Qinzhouhongli'and etc were with yield above the average and BBI below the average.Cultivars'Jizuili'and'Heiye'were with yield and BBI above the average.However,those good quality varieties such as'Guiwei'and'Nuomici'performed a low yield and strong biennial bearing character(high BBI).Learning from the experience of'Feizixiao'and'Baitangying'after fruit harvest,proposed key techniques to overcome the biennial bearing of litchi trees include re-structure of the orchard,sufficient supply of nutrients in a heavy bearing year,proper irrigation under the dry weather conditions,careful management of the terminal autumnal shoots,and stimulation of floral initiation before the critical time.