Properties Of The Complexed-type Of Light Conversion Greenhouse Films And Their Effects On Tomato Growth And Yield

Light quality exerts a significant effect on the plant growth,development and morphological construction.The previous research in our laboratory showed that the light intensity ratio of red and blue light to 3:1 could significantly promote tomato plant growth.Covering the suitable complexed-type of light conversion greenhouse film is conducive to improving the light environment under solar greenhouse and the yield and quality of tomato.On this basis,the experiment was conducted with‘Xianfeng No.4’and‘Lola’as the plant materials and the ordinary greenhouse film was used as the control,to further study the properties of light conversion,light transmission,anti-fog dripping,mechanical and thermodynamics of the films with complexed-type of light conversion agents including green to red and ultraviolet to blue light（T1）,green to red and ultraviolet to blue,far red light（T2）,green to red and ultraviolet to blue,red and far red light（T3）and their effects on the facility environment,plant growth,fruit yield and quality of tomato.The main results are as follows:1.The three complexed-type of light conversion greenhouse films were excited by green light at 530 nm and ultraviolet light at 379 nm,and produced strong red and blue emission peaks at 650 nm and 440 nm,among them,T3 was also excited by ultraviolet light at 355 nm,and produced a strong red emission peak at 660 nm.There was no significant difference between the light transmittance of light conversion film and that of control（CK）film without light conversion agent,and its water contact angle was lower than that of CK,especially T3has the smallest water contact angle,which makes the hydrophilic and anti-fog dripping performance of this film much better.Compared with CK,the mechanical and thermodynamic properties of the light conversion films were improved,among which,the mechanical properties of T3 were the best,and the horizontal and vertical tensile strength and elongation at break of this film was 6.56%,7.47%and 7.90%,4.72%higher than those of CK.In terms of thermodynamic properties,compared with CK,the crystallization temperature（T_c）,melting temperature（T_m）and initial decomposition temperature of the complexed-type of light conversion greenhouse films were all increased to varying degrees,and T3 was the best.2.Compared with CK,covering complexed-type of light conversion greenhouse films could improve the facility environment and promote tomato growth.Among them,T3 was the best,and the daily average temperature under this film was 1.21℃higher than that of CK,whereas the average humidity was reduced by 0.9%,followed by T2 and T1.Furthermore,compared with CK,the transmittance of violet,blue and green light under the complexed-type of light conversion greenhouse films was significantly lower than that of CK,while the transmittance of red-orange and far-red light was significantly higher.Among these light conversion films,covering T1 could significantly increase blue light transmittance and net photosynthetic rate of tomato leaves,this was beneficial to increase fruit yield,which was12.3%higher than that of CK.Covering T3 could obviously decrease violet light transmittance and increase red-orange light transmittance,thereby improving the structure of tomato leaves,and then promoting the synthesis of photosynthetic pigment in leaves and enhancing plant biomass,ultimately promoting lycopene accumulation by inducing the activities of lycopene synthase and dehydrogenase.In summary,the properties of the greenhouse films with addition of complexed-type of light conversion agents were all improved,and the facility covered with T1 and T3 could promote the photosynthetic capacity and plant growth,and then improve the yield and quality of tomato under facility in autumn and winter,respectively by optimizing the environment under these films and improving the structure of tomato leaves and inducing stomatal opening.