核桃實生苗二次移栽苗木生長特性研究

徐凱 夏玉芳 覃建文

摘 要：試驗將1年生實生核桃苗分為0.5～0.8 cm、0.8～1.0 cm、>1.0 cm 3個徑級進行移栽，通過移栽苗的成活率、苗高、地徑生長，來研究徑級與其生長的關系。結果表明：1）徑級對移栽苗成活率的影響，表現出苗木規格越大，成活率越高;以地徑>1.0 cm（Ⅲ）成活率最高，為83.75%;<1.0 cm（Ⅳ和Ⅴ）成活率低于80%。2）苗高、地徑總生長量從大到小依次為：Ⅲ（苗高100.4 cm、地徑1.984 cm）>Ⅳ（苗高68 cm、地徑1.658 cm）>Ⅴ（苗高62.8 cm、地徑1.385 cm）。3）苗高、地徑生長動態趨勢均呈 “S”型趨勢，地徑的生長總體呈現“慢-快-慢”的生長規律;從生長量看，苗高以徑級大的為好，Ⅴ、Ⅲ移栽后苗高生長增幅速度最大（分別為218%、214.96%）;而地徑生長以Ⅴ的增幅速度最大（225%），Ⅲ、Ⅳ較小（分別為186.29%、146.96%）。4）苗木總生物量，以大徑級最大（100.47 g），且隨著徑級的增大而增加。5）按照核桃苗木分級標準，Ⅲ和Ⅳ的合格苗比例較大（分別為93.94%、80%），Ⅴ的合格苗最少（50%）。綜合各項指標，Ⅲ徑級在苗高、地徑、生物量和出圃苗合格率上均高于其他兩種徑級，說明1.0 cm可作為進行二次移栽的最小地徑苗木標準。

關鍵詞：核桃移栽苗;成活率;苗高;地徑;生物量

文章編號：2096-8108（2020）05-0014-05 ?中圖分類號：S664.1 ?文獻標識碼：A

Abstract：Annual walnut seedlings were divided into three diameter classes to transplant in the test， the relationship between diameter classes and the growth of transplanted seedlings are studied via investigating the survival rate， the seeding height and the ground diameter. The results indicated that 1） The larger specifications of walnut seedlings， the higher survival rate of transplanted seedlings. The highest survival rate （83.75%） was shown in group Ⅲ when the ground diameter was greater than 1.0 cm， and the survival rate of group Ⅳ and groupⅤwere not more than 80% when the ground diameter was less than 1.0 cm.2）The seeding height and the total growth of ground diameter declines from 100.4 cm and 1.984 cm in group Ⅲ to 68 cm and 1.658 cm in group Ⅳ and even to 62.8 cm and 1.385 cm in group Ⅴ.3）The dynamic growth tendency of the seeding height and the ground diameter shows like “S”. The ground diameter presented slow-fast-slow growth pattern. Analyzed from the increment， the larger of the diameter， the higher of the seedling.Group Ⅴ and Ⅲ showed the largest amplification of seedling height growth （218%， 214.96%） and Group Ⅴ exhibited the larger amplification of basal growth （225%） than group Ⅲ and Ⅳ （186.29% and146.96%）.4） The biomass was decided by diameter classes and increases with the growth of diameter classes， the largest biomass was 100.47 g. 5）Group Ⅲ and Ⅳpresent the larger qualified ratio of seedlings （93.94% and 80%）， but group Ⅴshowed the least （50%）. Group Ⅲ taking into consideration various indicators， showed better height， diameter，biomass and qualified ratio than other specifications wich indicated that 1.0 cm could be choose to act as the seedling criterion of the minimum ground diameter for the secondary transplanting seedlings.

Keywords：transplanted walnuts seedlings; survival rate; seeding height; ground diameter; biomass

二次移栽是將苗床中的幼苗移栽到其他苗床的技術措施。二次移栽具有能促進苗木的側根和須根發生、提高苗木的造林成活率、嫁接成活率和苗木生長質量等優點[1-4]。核桃1年生實生苗主要用途，一是作為嫁接苗砧木，二是直接上山造林。核桃苗木合格苗出圃率的高低，直接關系到核桃苗木的質量優劣。

本研究圍繞未達到出圃苗合格標準的苗木，經過二次移栽后對其苗木生長與地徑的關系開展研究，通過其苗高、地徑年生長過程，分析其二次移栽后苗木生長效果及其出圃苗合格率，以期提出未出圃苗可進行二次移栽的最小地徑苗木標準，為核桃苗木生產提供參考。