Preliminary application of diffuse light film in a Chinese solar greenhouse

摘要： To explore the application of diffuse light film in a Chinese solar greenhouse (CSG), we did several comparative trials in CSGs in Beijing, Ningxia and Shandong provinces. We did three contrast tests on CSG cover films with average haze of 16.8 and 36.2%, including trials on tomatoes (in Beijing, seedlings; in Shandong, cultivation) and cucumbers (in Beijing, seedlings); the other four experiments used with films in an average haze 24.2 and 39.7%, which included trials on tomatoes (in Beijing, seedlings; in Ningxia, cultivation) and cucumbers (in Beijing, seedlings; in Ningxia, cultivation). Plant growth parameters, yield and quality index were evaluated. The result of preliminary tests showed that a higher haze film was able to improve homogeneity of light in the crop canopy and had a positive effect on cultivation. For example, in the contrast tests, we observed that a film with higher haze contributed to increases in plant height, stem diameter, leaf area, SPAD chlorophyll index, and seedling index; the seedling indices of tomatoes and cucumbers were enhanced by 50 and 10.5%, respectively, and their yields were increased by 17.0 and 21.9%, respectively, which demonstrated the outstanding impact of the higher haze films on production. Furthermore, it played a significant and positive role in flower bud differentiation of cucumbers, harvest time of tomatoes and cucumbers, and fruit quality of both crops. Based on the results of these preliminary tests, it can be concluded the diffuse film was able to accelerate plant growth and enhance crop production.