Influences of irrigating methods on growth and root system formation of summer cropping melon cultivated under root confinement in a vinyl house

Influences of irrigating methods on shoot and root growth of melons were studied under root confinement culture in a vinyl house from mid-June to late August 2004. The control (plot C) and three root-confined plots (LM, MF and SD) were designed. Plot C unconfined rooting zoon was irrigated by drip-watering at a relative short interval (at most 10 times a day according to the weather) in daytime. Plot LM and SD were also irrigated in the same way as plot C. Plot MF was irrigated by drip-watering at a long interval (at most 4 times a day according to the weather) in daytime. On basis of evapotranspiration rate, all plots were irrigated the same amount of water per day until one week before the harvest time. Prior to transplantation, plot C, LM and MF were sufficiently watered the whole surface of a ridge but plot SD was watered only the central zoon of a ridge. Roots in plot C distributed shallowly and widely. Roots in plot MF and LM also distributed shallowly and the amount of roots was less in plot MF. Roots in plot SD grew most vigorously and distributed most uniformly in a ridge. Fruit weight was relatively larger in plot C and SD than in 2 other plots. The peduncle length was shorter in plot LM than in other plots. The results suggested that the watering management in root confinement culture greatly affected the root growth, root system formation and fruit quality.