Effect And Simulation Of Different Temperature And Light On Growth And Quality Of Cucumber

Using cucumber TanSuo (Cucumis sativus L.cv.Tansuo) as the experimental material,dynamic changes of cucumber individual growth and the responses of its quality to different temperature and light conditions were systematically studied in 2014. According to the biological characteristics of cucumber, the calculation method of product of thermal effectiveness and photosynthetically active radiation (TEP) was improved, which based on TEP and growing degree days (GDD), Using Light and Temperature function(LTF) index. Research obtained needed temperature and light conditions by different sowing experiments and constructed simulation model of cucumber individual growth and several appearance and intrinsic quality indexes based on Light and Temperature, using independent experimental datas to validate simulation model. The main conclusions were as follows:(1) In the harvesting period, the fourth sowing period gets the maximum of plant dry weight, leaf area per fruit and fruit weight, while the second and fifth sowing periods take the second place, the third sowing period owns the minimum. Meanwhile, the fourth sowing period gets the maximum of soluble sugar and protein content, and the third sowing period owns the minimum. The cucumber plant dry weight and leaf area in different sowing date showed "s" type increase with growth, the same as the cucumber fruit weight, fruit length, fruit diameter, soluble sugar content and water content. The soluble protein of cucumber fruit declined exponentially, and vitamin C first increased and then decreased.(2) With the change of LTF indexes and growth of cucumber, the plant and fruit growth of cucumber showed different function relations. The cucumber plant dry weight, leaf area per fruit and fruit weight, fruit length, fruit diameter, soluble sugar content, water content changed in accordance with the logistic model function of LTF. The change of soluble protein content in fruits with LTF was in accordance with negative exponential function, vitamin C content in fruits with LTF increased first and then decreased and it showed the trend of variation with linear function.(3) Independent experimental data was used to test the LTF model,the results showed that the coefficient of determination 1:1 line (R2) was more than 0.950 between the simulated and observed values of cucumber plant dry weight, leaf area, fruit weight, fruit length, fruit diameter, soluble sugar and water content which were simulated in LTF model, indicating that the simulated values showed a high degree of fitness with the measured values while the RMSE values and revalues are smaller, compared with TEP and GDD, the simulation of the model was more accurate. The simulated value in LTF model of vitamin C and soluble protein content in fruit was mostly lower than the measured value, The simulation accuracy of vitamin C is lower than that in GDD model, and soluble protein was lower than that of TEP modelIn this study, we constructed models of cucumber plant growth and the main appearance quality, internal quality indexes of cucumber fruit based on light and temperature function. According to the input of daily average temperature and solar radiation, the growth of cucumber plants and the main appearance quality, internal quality indexes of cucumber fruit were predicted. This model is simple in calculation while it has high precision and reliable result and strong practicability. The results can provide theoretical basis and decision support for the light and temperature regulation of the annual production of cucumber in Greenhouse.