葉面噴施不同濃度鉀離子對‘台農1號’百香果果實品質之影響

Foliar Application of Different Potassium Concentrations Affects the Quality of 'Tainung No. 1'Passion Fruit (Passiflora edulis x P. edulis f. flavicarpa)

本試驗用硫酸鉀配置之鉀離子濃度為0 mg．L^(-1)（對照）、120 mg．L^(-1)、240 mg．L^(-1)與360 mg．L^(-1)的溶液進行葉面施肥，比較不同濃度鉀溶液對‘台農1號’百香果（Passiflora edulis x P. edulis f. flavicarpa）果實品質的影響。試驗結果顯示，採收時，處理組之果實鮮重介於82.2 g至83.6 g，高於對照組之71.6 g。以360 mg．L^(-1)處理者，總可溶形固形物含量（total soluble solids content）達20.1°Brix，高於對照組之19.2°Brix。以240 mg．L-1處理者，果汁率為21.6%，均顯著高於對照組之17.7 %。以240 mg．L^(-1)及360 mg．L^(-1)，處理者，果實內總可溶性醣含量（total soluble sugar content）分別為15.5%及23.8%，均高於對照組之7.0 %。葉面施用硫酸鉀肥亦可改變提高葉片的光合作用速率、蒸散作用及氣孔導度。綜上可知，鉀離子濃度在360 mg．L^(-1)對於果實品質的提升有的效果較佳。 This study aims to investigate the influence of potassium on the quality of 'Tainung No.1' passion fruit (Passiflora edulis x P. edulis f. flavicarpa) through foliar application. 'Tainung No.1' trees were treated with various concentrations of potassium：0 (as control), 120, 240, and 360 mg．L^(-1) made up from potassium sulfate. Foliar sprays of different concentrations of potassium significantly affected fruit fresh weight and juice percentage. Passion fruits of the trees that were subjected to potassium, exhibited higher levels of total soluble solids compared with control fruits. In addition, photosynthetic rate, transpiration rate, and stomatal conductance showed various differences after potassium application.