| The base temperature (Tb) of seed germination in cucumber cannot bedetermined directly and accurately. After the hypothesis that the effective accumulatedtemperature (TEA) are constant when the ratios of seed germination in cucumber aresame under different temperature conditions, a method with which the Tb of seedgermination can be accurately determined was designed, and a function modelbetween seed germination ratio and TEA was built up. With the POWERSIM software,a seedling growth model in cucumber was developed according to an experiment thateffects of different temperature on seedling growth cucumber. It was also investigatedthat effects of seedling inducement and fertilization with root-divided on yield,growth and development in cucumber. The results showed:1. According to the hypothesis that the effective accumulated temperature areconstant when the ratios of seed germination in cucumber are the same at 70% underdifferent temperature conditions, the base temperatures of seed germination incultivars Zhongnong 203 and Chiyu 401 are 10.48℃and 10.59℃, respectively, andthe active sum temperatures are 686.95℃*h and 704.85℃*h, respectively. Basedabove, a logistic function between seed germination ratio in cucumber rand TEA wasdeveloped, and it fitted very well when this function was validated.2. In a seedling growth experiment the relation between LnDW and t (growthperiod) could be simulated by a quadratic function, and the curve of simulation fittedthat of experiment well. Compared to the treatment 26/20℃, the plant height, leafnumber, fresh and dry stem weight, fresh and dry leaf weight, total fresh and dryweight and plant growth rate in cultivars Zhongnong 203 and Chiyu 401 in treatment22/16℃were significantly decreased.3. With the POWERSIM software, a model of seedling growth in cucumber wasdeveloped according to the results from the base temperature measure and seedlinggrowth experiments, and the simulation fitted experiment result very well. 4. The experiment of seedling inducement showed that female flower numberand the rate of female flower in cultivar Zhongnong 203 and Chiyu 401 in treatmentlow temperature, short day length and ethephon were significantly enhanced, and theblossoming date and node of first female flower were significantly advanced anddecreased, respectively. The experiment of low temperature inducement showed thatfemale flower number, the blossoming date and node of first female flower in cultivarEhuang 10 were significantly influenced by low temperature, while fresh fruit weightand total fresh plant weight had no significant influence. When the temperaturedifference between day and night was 6℃, it was optimal for dry matter accumulationin Ehuang 10.5. Compared to the control, no significant difference was found in total plantweight, fruit yield and plant development (leaf number and plant height) in thetreatment of standard solution and 1/2 standard solution; and cucumber fruit yield,fruit dry weight, total plant fresh and dry weight were significantly deduced in thetreatment of massive elements and trace element, respectively. Cucumber fruit yield,fruit dry weight, total plant fresh and dry weight were significantly increased in thetreatment of 2 standard solution and water and the treatment of 1.5 and 0.5 standardsolution, however, no significant difference was found in plant development (leafnumber and plant height). |
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