The effects of seeding times and fertilizing methods on the growth of Ryukyu-matsu (Studies on the planting method of Ryukyu-matsu (Pinus luchuensis Mayr)) (Forestry Experiment Station)

1.リュウキュウマツ造林の基礎資料を得るため, 播種時期別(12月5日から1月毎に5区)及び施肥法別(無施肥及び施肥深別5区)の試験をおこない, 発芽本数, 枯損率, 生育本数, 初年生及び6年生林分の樹高生長などを調査測定し, それぞれの結果を比較検討した。2.発芽及び枯損は, 気象条件, 特に温度と降水量に支配される。平均気温が15℃以下の冬季及び降水量の少ない時期は, 発芽が悪く枯損も多い。また種子の発芽能は7月まで持続することがわかった。3.生育本数は, 5∿7月頃が最も多く, それ以後はやや減少するか平衡状態を続ける。4.初年度の樹高生長は, 播種時期の早い12月5日播きの方が最も大きく, 他区の10倍以上の樹高生長をしめし, 施肥法別では, 無施肥区は施肥区よりもまた施肥深の大きいほど生長がすぐれていた。5.6年経過後の樹高生長は, 12月28日区で最も悪く, 他区の80%以下の生長量であった。施肥法別では, 無施肥区は施肥区の70%以下の生長量をしめし, 施肥深別では, 施肥深の大きい程大きい生長をしめす傾向がみえるが, 施肥深度は10cm区で最も生長が良かった。1. This study was in order to obtain a basic data of planting method of Ryukyu-matsu. The plots were setted the variety of seeding period and method of fertilization (Table. 1) 2. Germination of seeds and death of seedlings were influenced by the condition of temperature and rainfall. Germinative capacity of seeds continued until July. 3. Number of growing seedlings increased from May to July, and after August these number decreased. 4. At the one year period, the height of seedlings which was seeding on Dec. 5th, was highest among the seeding periods. The seedling height of the fertilized plots was higher than the control. Among the method of fertilization, the seedling height increased with increasing supplied depth. 5. At the six year test, the height of stands, which was seeding on Dec. 28th, was smallest and it showed less than 80% of the others. The height of stands in the control was less than 70% of the fertilized plot