Analysis And Simulation Of Factors Affecting Temperature Of Winter Tomato Leaves In Solar Greenhouse

Leaf temperature is an important physiological indicator of plant growth.Leaf temperature affects the plant water content,stomatal opening and closing state and leaf transpiration.Solar greenhouse is a closed system,greenhouse temperature,humidity,soil moisture,leaf transpiration,leaf moisture,CO2 concentration will have an impact on leaf temperature.As the winter greenhouse environment for the low temperature and humidity state,ventilation time and light time is short,so prone to disease.In order to improve the light and ability of tomato leaves,increase the yield and reduce the occurrence of disease,this paper chooses the tomato leaf temperature in winter to study the characteristics of winter solar greenhouse.A.Prior to the leaf temperature prediction model,in order to be able to detect tomato leaf moisture easily and quickly,this paper developed a tomato leaf moisture indicator,the indicator in the leaf humidity of 50?60%,60?70%,70?80%,80?90%,90 to 100%of the case,the indicator color gradually from blue to green transition to pink,the change is clearly visible,can change the indicator color quickly and intuitively indicating the then leaf moisture value,the indicator can be used The determination of the leaf moisture in the plant can provide guidance and help for the greenhouse production.B.Before the leaf temperature prediction is carried out,the position of the leaf temperature and the leaf temperature of the five measuring points in the greenhouse is first found.The position of the leaf temperature is the most representative of the greenhouse.At this position,the shading leaves are selected,The temperature of the leaves in the greenhouse was found,and the leaf temperature was measured.Finally,the environmental factors such as temperature,temperature,solar radiation,light intensity and carbon dioxide were monitored.The results were calculated by means of multiple linear regression model The leaf temperature prediction model of tomato leaves under different weather conditions was established by using the leaf temperature as the independent variable and other environmental factors in the greenhouse as the dependent variable.The experiment was carried out in the winter,the tomato was in the flowering and fruiting period,and the suitable temperature was 25?30 ?.Therefore,when the maximum temperature in the greenhouse was lower than 25 ?,the leaf temperature prediction model was Y = 54.316 + 0.607X1-0.157X2-0.014X3-0.001X5 +0.715X6-0.711X7-18.723X8-0.208X9,When the maximum temperature in the greenhouse is greater than or equal to 25 ?,the leaf temperature prediction model is Y =100.462 + 0.023X1 + 0.106X2 + 0.003X3 + 0.001X4 + 0.003X5 + 2.410X6-3.930X7 +14.256X8 + 1.839X9.In order to make the model more concise,this paper simplified the model of leaf temperature in different weather conditions by Pearson's correlation analysis,principal component analysis and gray relational analysis,and carried out the model precision test.Finally,When the maximum temperature is below 25 ?,the simplified model by principal component analysis is Y = 41.8-0.097X2 + 0.569X6-0.831X7-0.248X9,the maximum error is 1.67 ? and the total error is 17.98 ?.The fitting equation is Y =0.9026X + 0.2296,R2=0.8054,and the fitting degree is good.When the maximum temperature is greater than or equal to 25 ?,the simplified model by principal component analysis is Y =-4.698 + 1.143X1 + 0.045X2-0.006X3,the maximum error is 3.96 ?,the error cumulative value is 27.76 ?,the predicted value and the measured value are Y =0.9218X + 0.4049,R2=0.9495,Good degree.Therefore,in the actual production,the above method can be used to predict the minimum temperature of the leaves in the greenhouse,for greenhouse environmental control to help.