Preparation Of Replaceable Agricultural Light Conversion Film

Light conversion film is an effective method of achieving efficient utilization of "light fertilizer",which can convert the violet light,ultraviolet light and green light in sunlight that have little or even harmful impact on photosynthesis into red or blue light for effective photosynthesis.However,different crops or the same crop of different growth periods have different demands for light quality.The traditional light conversion film has a single light conversion effect and can not meet the changing needs of crops for light quality.In this study,a replaceable environment-friendly phototransfer film was prepared.Polyvinyl alcohol/Konjac glucomannan composite film was used as the base film to study the influence of the composition and proportion of film forming materials on the properties of the base film.Furthermore,the influence rule of the amount of light conversion agent on the performance of light conversion film was explored,and the optimal amount of light conversion agent was optimized.Finally,the application effect of light conversion film was tested through the application of different crops.The main research contents and conclusions are as follows:(1)In terms of light transmittance,the optimized film is composed of 3% PVA,0.4%KGM,0.3% glycerol and 0.1% sorbitol.The influence of film composition components on film water solubility is decreased in the order of PVA>KGM>sorbitol>glycerol.The film composed of PVA 1799: PVA 2699: KGM: glycerol: sorbitol: citric acid =1.0:2.0:0.4:0.3:0.1:0.2 can comprehensively meet the application requirements of stability,adhesion,light transmittance and environmental protection removal(swelling in water at50 °C)in high temperature and high humidity environment of the greenhouse.(2)The fluorescence intensity of the light conversion film first increases and then decreases with the increase of the amount of light conversion agent addtion.The fluorescence intensity of both the red and blue light conversion agents is the highest at a dosage of 0.8%.The increase of light conversion agent content will lead to the decrease of the transmittance of light conversion film.Overall,the optimal dosage of the red light conversion agent and the blue light conversion agent is 0.4% and 0.5%,respectively.According to the optimal dosage of fluorescent agent added to the optimized base film to prepare the light transfer film,the light transfer film can meet the requirements of its application in glass greenhouse.(3)The red light conversion film can promote the growth and development of lettuce.Compared to the control group without light conversion film,using the red light conversion film makes the number of leaves,plant height,stem diameter,fresh weight and dry weight above ground per plant of lettuce treated increased.The blue light conversion film can restrain the excessive growth of branches and leaves of cherry radish.Compared with the control group without light conversion film,using the blue light conversion film leads to leaf number,plant height,stem diameter,underground fresh weight and dry weight per plant of cherry radish decreased to a certain degree.