Application Evaluation Of New Plastic Films For Tomato And Paprika Production In Solar Greenhouses

The development and application of agricultural plastic film is one of the important achievements in agricultural sciences in the 20 th century, is also an important symbol of modern agriculture. Agricultural plastic film has become indispensable for the development of modern agriculture, and the rapid development of protected horticulture in China create conditions for the research and application of agricultural plastic film. In recent years, many domestic research units have paid more attention to this area, and some new products are available. To verify the application effects of these new type film, some newly developed films by Shandong Agricultural University were selected in the experiments, and comparative study on greenhouse environment and the growth of tomatoes and bell peppers was carried out, to find out the characteristics of the new films, and to provide theoretical and technical basis for the popularization of new films. The main results were as follows:1. Compared with inside-added EVA and PVC films, coated EVA film has better light transmittance, heat preservation and UV transmittance, can obviously promote the growth of tomato, and significantly increase the fruit sugar acid ratio, soluble sugar, lycopene and VC content, the tomato yield increased by 12.2% and 34.8% respectively.2. The performance of light conversion film and its effects on vegetables depend on the type of the agents. The transmission spectra showed that, when light conversion agents were added, UV and green were significantly reduced, red-orange and purple light were increased significantly. The best results were showed in coating film plus light conversion agent L, which has higher transmittance, and obviously promote the growth of tomato, 2-3 days earlier for flowering and fruit color-turning, and the yield were increased by 40.90% and 11.45% when compared to normal inside-added or coated film, at the same time, the lycopene and soluble sugar contents in the fruits, and sugar acid ratio were improved.3. The colored film changed light quality, and light transmittance dropped. Compared with colorless transparent film, red film made the stem diameter of sweet pepper increased, flowering and fruit-bearing advanced, with earlier fruit coloring; Blue film led to weak growth of sweet pepper, delayed flowering and harvest time, and slowed fruit coloring. Although red film caused a 3.43% reduction in yield, but increased the content of soluble sugar, free amino acid and sugar acid ratio, while blue film increased Vc and titratable acid content in fruit.4. Compared with normal EVA film, five layers co-extrusion multifunctional film increased red-orange light in transmission spectra, with higher light transmittance and longer duration. Five layers co-extrusion multifunctional film made sweet pepper healthy growth, and early fruit color-turning, the yield was increased by 18.33%, and Vc, soluble sugar content went up, while organic acid content in the fruits dropped.