Effects Of Sunken Depth Of Solar Greenhouse On Physiological Characteristics, Yield And Fruit Quality Of Tomato

A tomato cultivar, Taofen, was used to investigate effects of greenhouse depth on the growth, physiological characteristics, yields and fruit quality of tomato grown in organic substrate. Tomatoes were cultivated in sunken-type greenhouse from September 4, 2009 to March 2, 2010 as a wintering pattern, and from March 5, 2010 to August 10, 2010 as summering pattern.The treatments are four sunken depths of solar greenhouse, which were sunken 0m, 0.5m, 1.0m and 1.5m respectively. The main results were as follows:1. Opposite to the summer solstice, the highest temperature, minimum temperature and average temperature of greenhouse increased with increase of sunken depth. The 10 cm deep soil temperature of all greenhouses appeared fall-rise-fall diurnal variation rule on the winter solstice and the summer solstice. The light intensity decreased with increase of sunken depth of greenhouse and the highest light intensity of the winter solstice and the summer solstice respectively appeared about around 13:00 and 12:00. When the greenhouse depth was 1.5m, the wintering pattern tomato had an obvious effect on the tomato's growth. The treatment change was the most remarkable in the aspect of plant height, stem width, fresh weight of root, stem leaf and the area of the leaf. Whatever the winter solstice or the summer solstice, relative humidity in greenhouse linearly increased with the sunken depth of green house.2. When the greenhouse depth is 1.5m, the wintering pattern tomato had an obvious effect on the tomato's growth. The treatment change was the most remarkable in the aspect of plant height, stem width, fresh weight of root, stem diameter, leaf area. When the sunken depth is high, it also promoted the growth of the summer stubble tomato. But it was not as remarkable as the wintering stubble.3. When the greenhouse depth is 1.5m, photosynthetic function, nitrate reductase enzyme activity and root activity of the wintering pattern tomatoes, winter were significantly higher than other processing. The summering pattern tomatoes grown in 1.0m and 1.5 m sunken depth of the greenhouse were no significant differences in photosynthesis, and the tomato leaf of 1.5 m deep greenhouse NR activity was higher than other processing, each processing's root vigor showed significant difference, and had consistent late, achieved a high level at last.4. During winter cultivation, with the weak sunlight and low temperature condition, the tomato planted in the depth of 1.5m greenhouse increased chlorophyll content, heighten photosynthetic rate, prolong the period of high-light-effect, enhance photosynthetic power and augment photosynthate accumulated. And it could improve tomato's root system activity and NR activity. 5. The depth of greenhouse had a significant effect on the yield and quality of tomato for both of the wintering pattern tomato and the summering pattern tomato.1.5m sunken depth could promote the growth and yield of tomato and improve quality significantly. But there were no significant differences on tomato's quality between each treatment.To sum up, when the sunken depth of solar greenhouse was 1.5m, it had the best cultivation effects for tomatoes during winter. And sunken 1.0m was the best sunken depth for summer cultivation.