生分解性鉢による育苗がトマトの生育ならびに養分含有率に及ぼす影響 : 第2報定植後の生育(繁殖・育苗)  [in Japanese] Effects of Biodegradable Seedling Pots on Growth and Nutrient Concentrations of Tomato Plants : 2. Growth and Nutrient Concentrations after Transplanting(Propagation & Transplant Production)  [in Japanese]

植物成分を原料とした生分解性鉢で育苗されたトマト苗を用いて, 生分解性鉢を取り除かずに基肥量を変えた土壌に定植し, 定植後の生育および土壌中での鉢の分解程度について検討した.なお, 硬質ポリエチレン鉢で育苗し, 鉢を取り外して定植するポリ鉢区を対照とした.定植後11日目までは, 生分解性鉢区はポリ鉢区よりも草丈および葉数の増加が劣っていたが, 定植後11日目以降は生分解性鉢多肥区とポリ鉢区の生育は同程度となった.定植後26日目の各区における窒素, カリウムおよびリン含有率は, 生分解性パーム鉢のリン含有率を除いて生分解性標準区とポリ鉢区との間に差がなく, 生分解性多肥区はポリ鉢区より高かった.定植後26日目に生分解性鉢が形状をとどめていたが, 鉢底穴や鉢がもろくなった部分から鉢外に根が伸張し新たな根系を形成していた.以上のことから, 生分解性鉢区がポリ鉢区にくらべ初期生育が劣った原因は, 定植後, 鉢が分解されて根が鉢外に出るまでの間, 根域が制限され養分吸収が阻害されたことと考えられた.

Growth and nutrient concentrations in tomato seedlings grown in different types of biodegradable pots and plastic pots as control were investigated after transplanting with different amounts of fertilizer. The seedlings in biodegradable pots made with corn or palm were planted with the pots intact, while the plastic pots were removed before the control plants were planted. By 11 days after transplanting, the plants in biodegradable pots had developed shorter shoots and fewer leaves than the control plants. However, in the period subsequent to 11 days after transplanting, the plants in biodegradable pots given heavy applications of fertilizer grew similarly to the controls. At 26 days after transplanting, the concentrations of nitrogen, phosphate, and potassium in plants grown in biodegradable pots receiving the same fertilizer treatment as the control were similar to the control plants, with the exception of phosphate levels in the plants in biodegradable pots made with palm. These nutrient concentrations in plants in biodegradable pots that received heavy fertilizer after transplanting were higher than those in the controls. By 26 days after transplanting, the plants in biodegradable pots had roots extending from the bottom hole and/or biodegraded parts of the pots, and had produced new root systems outside of the pots; however, the pots were not fully degraded in the soil. This suggests that the low growth rate of the plants in biodegradable pots within the initial 11 days after transplanting was caused by the restricted root zone of the plants.