マツ類のさしきの発根に関する研究 : 第2報 噴霧装置によるアカマツの発根効果について

Abstract

1. マツ類のさしきの発根を促進する方法として, 1964年3月, ガラス室内に噴霧装置を作り, 空中湿度や温度が発根にどのような影響をおよぼすかをみようとした｡ 2. アカマツの3年, 7年および15年生母樹よりさしほを採取し, 黄色土壌 (土性 SL) にさしつけた｡ 3. 噴霧の時間間隔は, 8時から10時までと15時から17時までを2分間隔に30秒間噴霧とし, 10時から15時までを2分間隔に1分間噴霧とした｡ 4. その結果, 実験期間中における噴霧室内の空中湿度はつねに90%以上に保たれ, 最高温度は無処理区 (非噴霧) より5℃以上低かった｡ 5. もっとも高い生存率と発根率は, 各母樹年令とも噴霧処理区でみられた｡ とくに15年生母樹では, 150日間の噴霧で14%の発根率を示した｡ 6. もっとも高い発根率を示した噴霧期間は母樹年令によって異なった｡ 7. 根の生長量は20~50日間の噴霧で大きくなり, 主軸の伸長量は噴霧期間が長いほど大きかった｡ 8. 以上の結果, アカマツのさしきでは, 噴霧装置によって空中湿度を90%以上に保つとき, 根の形成に効果があることがわかったが, 最高の発根率を示す噴霧期間は, 母樹の諸条件によって, いちじるしく影響されるように考察される｡

1. In order to inquire the reason upon rooting difficulties of the pine cuttings, in March 1964, the studies was carried out to clear the influence of humidity on root-forming by misting practice. 2. Cuttings were taken from the mother trees of three, seven and fifteen-year-old of Japanese red pine (Pinus densiflora Sieb. et Dicc.) and planted in the yellow colored soil of sandy loam. 3. Misting practice was effected by the lateral spray system operating thirty seconds of every two-minute period from 8 a.m. to 10 a.m. and from 3 p.m. to 3 p.m., and one minute of every two-minute period from 10 a.m. to 3 p.m. 4. As the results, humidity in the misting frame was kept at 90% over during the experimental period, and the maximum temperature was fallen in 3℃ over compared with the non-misting. 5. Rooting ability was raised by the misting practice, and the cuttings were taken from fifteen-year-old mother tree showed at 14%. 6. The periods of misting treatments after planted to show at the highest percentage of root-forming distinctly differed by the age of mother tree. 7. Growth amounts of the roots were large at the misting period from 20 to 50 days, and it tends the elongation of main stems of rooted cuttings to inclease in proportion to the misting period. 8. As above mentioned, it was ascertained the environment of humidity 90% over by the misting practice to be efficient upon the root-forming of Japanese red pine cuttings, but the misting period shown the highest rooting percentage is considered to be remarkably affected by some factors of the mother trees.