Development Of A New Soilless Culture System For Nettedmelon In Southern China And Related Cultivation Techniques

Melon (Cucumis melo L.) is grown widely and ranked ninth of the ten most important fruit vegetables in the world. In China, melon is traditionally grown in the arid northwest China, where the high temperature, intense light and high day/night gradient are suitable for its culture. With the continuing development of China抯 economy and improvement of people抯 living standards, planting melon in eastern China has been studied and applied. Besides breeding varieties for disease-resistance, humidity tolerance and high sugar content, a breakthrough in cultural practice has also been made. For the high humidity and rainy conditions in southern China, a new soilless culture system has been developed and studied thoroughly, and some critical techniques (including irrigation system, graft, and in vitro propagation) have also been studied. A complete and p~ractica1 technical system has been built. The main results are as follows: 1. A new special soilless culture system for protected melon production in southern China with damp and rainy climate was invented and patented. The figure of the device is like a flower pot with a closely filling hat-like core in its center to separate the pot into 3 parts for substrate, air and nutrient solution. Roots of melon could grow not only in the media but also into the cavity of the pot to absorb sufficient oxygen and nutrients. This special structure successfully balanced the supply and demand of oxygen, water and nutrients. The culture system could be effectively used in overcast and rainy southern China because the features of this system are easily movable, advancing transplant and saving substrates and nutrient solution. Since the special structure had no leaching of nutrient solution, the system significantly decreased the humidity of the ground and greenhouse, thus the incidence of disease was also decreased. 2. Netted melon was cultured in two soilless culture systems of trough and pot filled with different media (river-sand or reed), some pots enclosed with black non-woven cloth (enclosed pot) and some painted black (painted pot), the media temperature and melon growth were measured during the seedling and flowering phase. All media temperatures raised or dropped along with the indoor temperature, but temperature change in sand synchronized with air temperature and that in reed media lagged behind the air temperature. Temperature in the patented pot changed more sensitively and the range between daytime and night was wider thanjhese of trough. The media temperatures in the painted pot and enclosed pot were higher than that of trough in daytime. In the same cultivation system, the melon grew better in reed Iv substrate than in sand in early spring, and melon in the patented pot grew better than in trough with the same media. The tdmperature in pot was lower than that in trough during night when the minimum air temperature was below 15 C, and the lower the minimum air temperature, the longer the pot maintained. The media temperature of pot was affected little by indoor temperature when the plants grew higher. 3. After fruit setting, the CO2 accumulation and 02 depletion in the cavity of the patented pots (some were ventilated from the flowering phase) were detected. During the netting phase, 02 concentration difference between the inner and outside of the patented pots filled with reed substrate increased sharply to 8.5% from 2.0% in 7 hours when the pots?mouth and...