A Regression Model of Dry Matter Accumulation for Solar Greenhouse Cucumber
The objective of this study is to develop a regression cucumber dry matter production model with a minimum number of parameters. Cucumber (Cucumis sativus L.) was cultivated in a soilless system with drip irrigation. The substrate was peat mixed with vermiculite. Five experiments were fulfilled totally in 3 different places in Beijing of China from 2004 to 2005. Cucumber growth data (dry matter weight of leaf, stem, fruit and petiole) were measured and environmental data (temperature, light intensity and day length) were collected. Data collected from 1 experiment in solar greenhouse was used to build the model, which was further validated with the data collected from other 4 experiments in solar greenhouse. A regression model for cucumber dry matter production was established. Based on Logistic curve, the time state variable was expressed as a logistic function about effective temperature accumulation (ETA) and effective light intensity accumulation (ELIA). ETA was defined as the sum of the temperature that was higher than physiological zero point in certain period, and ELIA was defined as the sum of the light intensity that was higher than light compensation point multiplied with time in certain period. Temperature, light intensity and day length were synthetically considered. The model had less state variables, and provided the relationships between the cucumber dry matter accumulation (DMA) per plant and environmental data (temperature, radiation and day length). The result of simulation was satisfied, because RMSE value was less than 6, and the R2 value of the results was 0.99. It indicated that the regression model for cucumber dry matter production was reasonable and feasible.
Keywordscucumber dry matter accumulation regression model effective temperature accumulation effective light intensity accumulation
- Heuvelink E. Tomato growth and yield: quantitative analysis and synthesis. Wageningen. 1996.Google Scholar
- Katharine B. Perry, Todd C. Wehner. A heat unit accumulation method for predicting cucumber harvest date. Horticultural Technology. 1996, 6(1): 27-30.Google Scholar
- Li Lei, Lou Chunheng, Wen Rujing. Study on the Dry matter Accumulation and Distribution with Various Densities in Cotton. Acta Agriculturae Boreali-Occidentalis Sinica 1996, 5 (2): 10-14.Google Scholar
- Li Pingping, Wang Duohui, Deng Qingan. A Study of Dynamic Growth and Potential Production Simulation Model of Salad in Greenhouse. Journal of Biomathematics, 1999, 14 (1): 77-81.Google Scholar
- Liu Guiru, Zhang Rongzhi, Lu Jianxiang. Study on Grain Filling Characteristics of Wheat Cultivars Tolerant to Drought. Journal of Agricultural University of Hebei. 1994, 17(4): 43-47.Google Scholar