Effects of low light intensity after fruit set on growth and quality of oriental melon (Cucumis melo var. makuwa makino)

摘要

This experiment was conducted to investigate the effects of different levels of light intensity (100, 200, 400 mu mol centre dot m~(-2) centre dot s~(-1), and natural light) on the growth and the fruit quality of oriental melon (Cucumis melo L. var.makuwa Makino). Plant height and stem diameter showed no significant differences among treatments. However, leaf area, root length, fresh weight, and dry weight were higher under the natural light condition and decreased with reducing the light intensity. Photosynthesis rate and total chlorophyll contents also decreased with reducing the light intensity. Root activity was higher under the natural light condition than under low light intensity even though there were no significant differences among thelow light intensity treatments. The trans-zeatin content in leaves under the natural light condition was two to three times higher than those under the low light intensity. The size of stoma and stomatal aperture decreased with reducing the light intensity. The chlorosis of leaves and fruit drop increased with the reduction in light intensity. Marketable fruit yield was 1,351 kg per 10 a under the natural light, but was very low under the low light intensity, giving no fruit harvest under the light intensity of 100 mu mol centre dot m~(-2) centre dot s~(-1).