Model Establishment And Research On Couple Effects Of Environmental Factors On Controlling Tomato Growth In Greenhouse

High quality and efficient production in greenhouse depends on environmental controlling that makes the crop its core.There are relationships of quick transmission and instant response between greenhouse environmental factors like temperature,PAR,relatively humidity and physiological metabolism in crops.The environmental factors act together to crops.And there are some complex interactions and paths of feedback regulation between them.Therefore,multiple-factor controlling is different from the composition and combination of optimal effects of single environmental factors,it's hard to be measured precisely.Tomato,the horticultural crop that has the largest greenhouse vegetables area in China,was limited its production and quality improvement by being exposed to the condition of low temperature and low light and rough management of greenhouse environment in winter and autumn season and in early spring.Thus,researching on couple effects of environmental factors and crops'growth conditions and the model of coordinated regulation between greenhouse environmental factors is of great significance for promoting high quality and effect production,controlling and managing the greenhouse environment precisely and reducing the cost of regulation.The experiment studies tomato by artificial control and simulation of the environment in winter and autumn season and in early spring in greenhouse.Based on the experimental factors like air temperature,relative humidity and PAR,a composite quadratic orthogonal regressive rotation design was adopted to characterize the different combinations of environmental factors in effecting greenhouse grown tomato at seedling,flowering and fruiting stages.Controlling effects of environmental factors on major growth and physiological processes of tomato at different stages are analyzed to build the response models of environmental factors on comprehensive tomato growth at different stages,to get the solution of environmental parameters optimization of tomato in greenhouse.The main results are as follows.1.Dry matter accumulations,net photosynthetic rate and transpiration rate were measured under different combinations of environmental factors based on tomato plants and leaves at different stages.Characterizations of main effect,single effect and marginal effect for each environmental factor were determined and illustrated by using the environmental data.Dry matter accumulations of tomato were mainly affected by air temperature at seedling stage and fruiting stage,and were mainly affected by relative humidity at flowering stage.Effects of single environmental factor like air temperature,relative humidity and PAR on tomato at seedling stage could be estimated with a downward parabola,a linear increasing function and a parabola going up.Effects of single environmental factor like air temperature and PAR on tomato at flowering stage could all be estimated with linear increasing functions.The effect of single environmental factor of relative humidity on tomato at flowering stage could be estimated with a downward parabola.The effect of single environmental factor of air temperature on tomato at fruiting stage could be estimated with an upward parabola.Effects of single environmental factor like relative humidity and PAR on tomato at fruiting stage could all be estimated with linear increasing functions.Marginal effects of air temperature,relative humidity and PAR on tomato dry matter accumulation at seedling stage were negative,negative and positive.The marginal effects of air temperature,relative humidity and PAR on tomato dry matter accumulation at flowering stage were positive,negative and negative.Marginal effects of environmental factors on tomato at fruiting stages were positive.Net photosynthetic rate of tomato were mainly affected by relative humidity at seedling stage,were mainly affected by PAR at flowering stage and were mainly affected by air temperature at fruiting stage.Effects of single environmental factor like air temperature,relative humidity on tomato at different stages were estimated with downward parabola.Effects of single environmental factor of PAR on tomato at different stages were estimated with linear increasing functions.Marginal effects of air temperature and relative humidity on tomato at different stages were negative.Marginal effects of PAR on tomato at seedling stage and fruiting stage were positive,but negative at flowering stage.Transpiration rate of tomato were mainly affected by air temperature at different stages.Effects of single environmental factor like air temperature,PAR on tomato at different stages were estimated with linear increasing functions.The effect of single environmental factor of relative humidity on tomato at seedling stage was estimated with a downward parabola.Effects of single environmental factor of relative humidity on tomato at flowering stage and fruiting stage were estimated with linear increasing functions.Marginal effects of environment factors on tomato at seedling stage were negative.Marginal effects of air temperature,relative humidity and PAR on tomato at flowering stage were positive,positive and negative.Marginal effects of environment factors on tomato at seedling stage were positive.2.Weights of single tomato growth evaluation indicators were determined.The comprehensive tomato growth was evaluated based on TOPSIS model.And the response models of environmental factors on comprehensive tomato growth at different stages were given.The most suitable combinations of environmental factors for tomato growth were determined based on the response model of environmental factors on comprehensive tomato growth at different stages.The most suitable combination of environmental factors for tomato growth at seedling stage was as follows:air temperature was 27.6?,relative humidity was76.1%and PAR was 396.3?mol·m^-2·s^-1.The most suitable combination of environmental factors for tomato growth at flowering stage was that air temperature was 29.3?,relative humidity was 74.3%and PAR was 366.5?mol·m^-2·s^-1.The most suitable combination of environmental factors for tomato growth at flowering stage was that air temperature was26.8?,relative humidity was 79.6%and PAR was 396.3?mol·m^-2·s^-1.3.Three solutions of environmental parameters optimization of tomato in greenhouse were given,based on temperature,humidity and PAR.And the effects of synergetic control between environmental factors were explored.When the air temperature in the greenhouse was certain,the reasonable adjustion of humidity and PAR can promote tomato growth.The increase of relative humidity promoted the growth of tomato more significantly than the increase of PAR in seedling stage when the greenhouse's air temperature was 20.8?.Only increasing air temperature and PAR at the same time,the tomato growth can be promoted at fruiting stage.Light supplement promoted tomato growth at seedling stage a little in greenhouse when air temperature was 25?and relative humidity was higher than 75%.When air temperature was 29.2?and the range of relative humidity was 75%⁸5%in greenhouse,the increase of PAR promoted tomato growth ineffectively.However the temperature was more suitable for tomato growth at fruiting stage which responded nonsignificantly to relative humidity and PAR in the meantime.When the relative humidity in the greenhouse was certain,the reasonable adjustion of air temperature and PAR can promote tomato growth.When the relative humidity was 66.1%,increasing air temperature and PAR at the same time can promote tomato growth at different stages.When the relative humidity was 75%,the effects of synergetic control between air temperature and PAR on tomato at seedling stage were nonsignificant.Under this relative humidity,increasing PAR was also nonsignificant to promote tomato growth at fruiting stage.But when the relative humidity was 83.9%,increasing air temperature and PAR at the same time can promote tomato growth significantly at flowering and fruiting stages.When PAR in the greenhouse was certain,the reasonable adjustion of air temperature and relative humidity can promote tomato growth.When PAR was 240.5?mol·m^-2·s^-1,the air temperature and relative humidity were optimized.The results showed that the increase of relative humidity promoted tomato growth more significantly than the increase of air temperature at seedling stage.Under this light condition,increasing air temperature can significantly promote tomato growth in greenhouse at flowering stage when relative humidity was 70%⁸0%.When PAR was 300?mol·m^-2·s^-1,it is ineffective for the increasing of air temperature to promote tomato growth at seedling stage.Under this light condition,the effect of air temperature control on tomato growth at fruiting stage was a little when the air temperature was higher than 25?.When PAR was 360.5?mol·m^-2·s^-1,and the relative humidity was higher than 75%,increasing air temperature promoted tomato growth nonsignificantly at seedling stage.Under this circumstance,the most suitable temperature and humidity at flowering and fruiting stage respectively were 27?,70%⁸5%and 25?²9?,75%⁸5%.