Potential for the Usage of Current-year Seedlings and Year-round Planting of Containerized Pinus Thunbergii Seedlings

27 Mar Potential for the Usage of Current-year Seedlings and Year-round Planting of Containerized Pinus Thunbergii Seedlings

View Original

Abstract

現在東北地方の津波被害地では広範囲の海岸林の早急な再生のため, 大量のクロマツ苗の植栽が必要になっており, 育苗期間の短縮と, 作業の平準化のための通年植栽が求められている。そこで, 当年生苗の利用可能性と通年植栽の可能性を検討するため, 宮城県仙台市において, 当年生コンテナ苗と 2 年生裸苗の成長比較試験と, コンテナ苗を厳冬期の1 月を除き, 2 カ月おきに通年で植栽する試験を行った。その結果, 11 月下旬と 3 月下旬植栽の当年生コンテナ苗の成長後の幹長と地際直径は 2 年生裸苗と有意差がなかった。幹長の成長量は, 3 月植栽で裸苗よりやや劣ったものの, 11 月植栽のコンテナ苗では同等で あった。地際直径の成長量は, コンテナ苗の方が有意に多かった。コンテナ苗は, いずれの植栽時期でも越冬後の活着率が98.4%以上と高く, 成長に大きな問題もみられなかった。以上のことから, 当年生苗の利用と通年植栽は, ともに可能と考えられた。

English Abstract

A large number of Pinus thunbergii seedlings are required for establishment in coastal areas after the tsu mi disaster. Therefore, a reduction in the duration of seedling nursing period and year-round planting to equalise the amount of work are required. We compared the stem growth of current-year containerised seedlings (CCS) and 2-year-old conventio l bare-root seedlings (TBS), and planted the containerised seedlings every 2 months except during midwinter (January). There was no significant difference between the stem length of CCS and TBS after one growing season. For CCS planted during March, stem longitudi l growth was smaller than that of TBS; however, for those planted during November, no significant difference was noted. Stem radial growth of CCS was higher than that of TBS. Seedling percentage survival rates of CCS after one growing season was high (>98.4%), regardless of the planted month. In conclusion, usage of current-year seedlings and year-round planting of containerised seedlings could be possible in the regions with environmental conditions similar to the study area.