| The irrigation model based on tomato plant real-time growth was studied to solve the problem that traditional crop growth model simulation inaccuracy when environment changes in solar greenhouse.The test materials were the large fruit type tomatoes ’Ruite fenna’ and’DF-09’,the culture substrate formula was developed by our research group.Our research contains the plant growth,the effects of different environment factors and the irrigation models based on tomato plant real-time growth during winter-spring and autumn-winter periods in solar greenhouse in order to solve the problem that traditional crop growth model simulation inaccuracy when environment was not suitable in autumn-winter period and provide theoretical basis and technical guidance for accurate irrigation and automatic control of tomato in solar greenhouse.The main findings are as follows:1.Developing tomato plant real-time growth measuring system,which includes three parts,electronic crane scale,data collection and computer.The system can weigh tomato plant real-time growth（stem weight + leaf weight + fruit weight）.The data were automatically collected,transmitted and recorded once every 10 min on the computer.The calculation formula for daily tomato plant real-time growth was the next day’s electronic crane value minus the previous day’s value at the same moment.2.The actual growth value of the tomato plant obtained by actual sampling was used to verify the tomato plant real-time growth value calculated by the weighing scale system.By comparing the difference between the five daily tomato plant real-time growth values calculated from the five time points 00:00,05:00,06:00,07:00 and 08:00 and the actual growth of tomato plant.The results show that the subsequences were in good agreement at 00:00 during both winter-spring and autumn-winter growing seasons,and R2 are 0.8274 and 0.8722,respectively,they all exceeded 80%.Tomato plant real-time growth during winter-spring growing season was between 10 and 100 g and 10 and 30 g during autumn-winter growing season,which indicates the tomato plant real-time growth during winter-spring growing season was about 3 times of the autumn-winter growing season.3.By analyzing the effects of environmental factors（light intensity,greenhouse temperature,substrate temperature and TEP）on the tomato plant real-time growth during winter-spring and autumn-winter growing seasons,it was shown that the environmental condition of the previous day determines the growth of the second day.It is to say that if the environmental conditions of the previous day are good（the light intensity and TEP are large,the greenhouse temperature and substrate temperature are both high）,the growth of the second day is large,if the environmental conditions of the previous day are bad（the light intensity and TEP are small,the greenhouse temperature and substrate temperature are both low）,the growth of the second day is small.By using the method of Pearson correlation analysis we compared the largest environmental factor on tomato plant real-time growth.The results showed that the most important environmental factor influencing the tomato plant real-time growth in the two growing seasons both were TEP.Therefore,TEP was selected as the model’s independent variable to study the irrigation model.4.The irrigation models based on tomato plant real-time growth during winter-spring and autumn-winter growing seasons were Z = a×（X×Y）2+b×X+c×Y+d and Z = a + b×exp（c/X）+ d × Y,respectively,where a,b,c and d are different parameters,X is the tomato plant real-time growth（g）,Y is TEP(MJ·m-2),the mean square error is 120.1638 and 58.2260,respectively,the coefficient of correlation is 0.8015 and 0.9000 respectively,and the validation coefficients is 0.7095 and 0.7679,respectively.By analyzing the mean square error,correlation coefficient and validation coefficient of the two growing seasons,it is indicated that the tomato irrigation model of the autumn-winter growing season was superior to the winter-spring growing season,and the irrigation model of the autumn-winter growing season is simple,can be used in the actual production.In summary,a hanging scale weighing system was established for the tomato plant real-time growth of solar greenhouse in this paper,which can weigh the growth of tomato plant in real time.The tomato plant real-time growth was verified by the actual growth of tomato plant,it was indicated that the calculation of tomato plant real-time growth amount was the most accurate according to 00:00.Pearson correlation analysis showed that TEP was the most important environmental factor affecting tomato plant real-time growth.Tomato irrigation model was established based on real-time growth during winter-spring and autumn-winter growing season,and compared with the irrigation model based on tomato growth model. |
