マツ属の成長休止期におけるさし木の研究 (予報)

Abstract

本実験は内外産マツ類10種 (P. deniflora, P. Thunbengii, P. radiata, P. Ayacahuite, P. Pungens, P. virginiana, P. echinata, P. Griffitii, P. Peuce, P. luchuensis) の伸長量を7日目ごとに測定し, 伸長が一時休止した夏のはじめに当年生の側枝を1次枝と2次枝とにわけて採穂し, 赤土と鹿沼土の床にさしつけた｡ 翌年4月28日一斉に掘りとり調べた結果次のとおりであつた｡ P. Pungens, P. echinataは100%の枯死をしめした｡ 他のものはわずかながら活着したが, 発根は非常にひくかつた｡ 発根率は P. radiata がもつともたかく30%, 次いで P. Ayacahuite が7%, P. virginia が5%であつた｡ さし穂の大きさにかなりの差があつたから, 厳密には比較出来ないが, 1次枝と2次枝とでは2次枝の方が発根率はたかかつた｡ 赤土床に挿しつけた場合は鹿沼土床に挿しつけた場合より多少よく発根した｡

This repot deals with the results of the experiments on the rooting behavior of the cuttings, which were collected from the pines (seven ~ nine years old) in the first summer when the elongation growth of pines was once stopped. As the cutting materialt, the authors used the first and the second branches of the ten species. These species were P. densiflora, P. Thunbergii, P. radiata, P. peuce, P. Ayacahuite, P. pungens, P. virginiana, P. echinata, P. Griffitii and P. luchuensis. In June ~ July 1957, the cuttings were planted on the Kanuma and redish clawey loam, and the condition of the rooting was investigated in April 1958. 1) All the cuttings of P. pungens and P. echinata withered, while those of the other species survived (41 ~ 3%). 2) P. radiata rooted up to 30%, P. Ayacahuite 7% and P. virginiana 5%. All cuttings of the other species were not rooted. 3) The cuttings taken from the 2nd branch showed a fairly good rooting percentage in comparison with those taken from the 1st branch. But in view of the fact that these cuttings differred considerably in length, this comparison cannot be accurate. 4) As the propagating media, the redish clayey loam was better than the Kamuma soil.