密植桃樹夏季回縮修剪技術研究

吳中平

摘要 主干形和“Y”字形是密植桃樹常用的樹形。為了避免密植樹形主干上的結果枝組過長，必須進行適時回縮。本研究選用三年生桃砧中油13號“Y”字形和主干形植株，進行了二年生枝的夏季回縮修剪強度及回縮時期對其上新梢生長和成花的影響試驗。結果表明，在5月中旬，將主干形植株上二年生枝留基部2、4、8個葉叢枝回縮對再發新梢的增粗、增長及成花沒有顯著差異，再發新梢的成花均較好；在5月中旬和6月中旬對“Y”字形桃樹上所有二年生枝留基部2個或3個葉叢枝回縮修剪，再發新梢的成花均較好，但6月中旬回縮后的再發新梢的空節率和單花芽率明顯升高，復花芽率有較大降低。

關鍵詞 桃樹；主干形；“Y”字形；夏季回縮；新梢長度；總果枝率

中圖分類號 S662.1 文獻標識碼 A 文章編號 1007-5739（2017）22-0053-02

Abstract The peach tree structure in cordon shape or in ′Y′ shape were mostly adopted in dense planting peach cultivation. In order to avoid fruit shoots on the trunk too long，retraction pruning was commonly adopted. This study chose three-year-old Zhongyou 13 peach trees with the ′Y′ or corden shape tree structure，the effects of retraction time and retraction strength on shoot growth and flower bud formation were studied.The results showed that the retraction pruning treatments at the 2，4 and 8th shoots with leaf bush away from the branch base on the biennial branches for the corden shape trees in mid-May had no significant difference in growth and flower bud formation for the new shoots on them，and the flower bud formation of the new shoots were all good for these treatments. The flower bud formation on new shoots were all good too between the retraction pruning treatments in mid-May and mid- June for ′Y′ shape trees，but the no bud node rate and the rate of nodes with single bud for the treatment in mid-June were higher than one in mid-May，and the rate of nodes with multiple flower buds for the treatment in mid-June was lower than that in mid-May.

Key words peach tree；corden shape trees；′Y′ shape trees；retraction pruning in summer；length of new shoots；total fruit shoot rate

我國傳統桃樹樹形多采用三主枝自然開心形，桃樹種植密度495～825株/hm2，但自然開心形具有結果晚、修剪量大、產量低、更新不易等缺點，且不適合密植栽培。現在世界各國在果樹栽培方面都趨向于矮化密植栽培，桃樹具有結果早、成形快、壽命短等特點，更需要矮化密植栽培。密植桃樹的樹形主要有主干形和“Y”字形，這些樹形整枝簡單，作業方便，結果快，產量高，目前在我國推廣較快[1-4]。但是，密植桃樹采用的是強干弱枝的密植栽培模式，主干上直接著生結果枝組。若結果枝組過長、過大，會引起植株密集擁擠、內膛快速光禿、外圍結果的現象[5]。本文以主干形和“Y”字形2種樹形的三年生桃砧中油13號油桃為試驗材料，研究了夏季回縮修剪強度及時期對再發新梢的生長成花的效應，以解決密植桃園枝組過長、過大的問題。……