Studies on the folia supply of horticultural plant : I Effect of potassium phosphate monobasic (KH_2PO_4) and sucrose on the quality of net melon (Department of Agriculture)

ネットメロンの品質向上対策の一環として, リン酸-カリと蔗糖の葉面散布の効果について検討を行なった結果, 次の諸点が明らかとなった。1交配10日, 20日, 30日後の3回にわたって, リン酸-カリ500倍にクエン酸500倍加用の散布区は糖度が著しく高くなり, 1%レベルで有意の差が認められた。2交配10日, 20日, 30日, 40日後の3回散布されたリン酸-カリ及び糖のクエン酸加用区も0.7度以上もの糖の増加が認められた。3交配20日, 25日, 30日, 35日, 40日後の5回にわたって散布されたリン酸-カリ及び糖のクエン酸加用区は, いずれも糖含量が低下し多用の結果は逆効果となることが認められた。4クエン酸を加用せず, リン酸-カリ単独散布の場合は5回散布区の糖度が高くなっておりクエン酸加用の効果が認められた。クエン酸の濃度については500倍と1000倍区の間では差は認められなかった。5果肉の厚さについては処理間に差は認められなかったが, 果重については処理区はやや減少することが認められた。6処理区は全般に葉が立ち気味となり, 受光体勢が改善され, 糖度の高い区程, 顕著であった。As one of the methods to prevent how to make high-quality net melon, the folia supply by KH_2PO_4 and sucrose of the effect to the quality of net melon was investigated, The results obtained are briefly summarized as follows; 1. Folia supply of KH_2PO_4 by 500 times with citric acid of 500 times on 10,20,and 30 days after pollination, the sugar content of fruits became higher than the nontreatment. The signifcant of 1% level was recognized. 2. Three times of folia supply of KH_2PO_4 and sucrose with citric acid of the same concentration on 20,30,and 40 days after pollination, the sugar content increased more than 0,7 percent. 3. Five times of folia supply of same concentration on 20,25,30,35,and 40 days after pllination, the sugar content became reducing although the supply times were encreased. 4. In this case of mono supply of KH_2PO_4 without citric acid the sugar content became higher when given five times than three times. It means the effect of citric acid as carrier was proved. The effect of concentration of citric acid was not recognized betweem 500 times and 1000 times., 5. The thickness of fruit was not diffrent between each treatment and nontreatment. The weigh of fruit on traetment was less than slightly. 6. The leaves treated became setting up rightly compeard with nontreated leaves. The treated could received the sun shine easily which means the sugar content would be increased remarkably