アールスメロン（Ｃｕｃｕｍｉｓ ｍｅｌｏ Ｌ．）の葉内無機成分に及ぼす着果の影響

Abstract

We examined changes of mineral composition in leaves of muskmelon (Cucumis melo L.) after removal of fruits at various intervals. Total chlorophyll in first leaf on bearing branch was increased in 30-day and 45-day fruit-removal. In 60-day fruit-removal, it decreased rapidly from 15 days, and reached the lowest level at the time of harvesting. Phosphorus in leaves on bearing branch increased rapidly from 30 days in 45-day and 60-day. Potassium in leaves of main stem were lower in fruiting than in non-fruiting, and there were lower in the treatments with the fruit for longer periods. In first leaf on bearing branch, potassium in leaves of the main stem increased gradually up to 60 days. In fruiting, it increased slightly, but in 60-day, it decreased rapidly from 30 days, and reached about 1/3 of that of non-fruiting 60 days. In all treatments, calcium in first leaf on bearing branch increased rapidly up to 30 days, and then slightly decreased. The decrease rate was highest in 60-day. Magnesium in leaves on bearing branch increased up to 60 days. These results indicated that mineral composition varied with stage of fruiting and position of leaves. Potassium moved into fruits, and most strongly affected first leaf on bearing branch closest to fruits, suggesting development of etiolation. In further studies, it is necessary to examine relationship between mineral composition and quality of the fruit, and to improve quality of the fruit.