Development of colored-woven films and demonstration of ginseng seedling production in a greenhouse

Abstract

Ginseng has some chronic problems caused by the conventional shading structure. Although greenhouse cultivation has been expanded as an affordable alternative solution, no suitable colored woven film (WF), considering the durability, environmental changes, and growth parameters, has yet not been developed. After checking the light reflectance, solar light transmittance, and spectral photon flux distribution of various colored WFs, pearl WF (high light reflectance of 90% and close to 1.0 B/R light ratios) is expected to have positive effects such as increasing growth by manipulating B/R light ratios including temperature reduction due to albedo difference was mass-produced. In this study, 85% two-layered black shade net with general polyethylene film (black PE), blue WF, and pearl WF were covered on the greenhouses to investigate microclimate and growth ginseng. Spectral light through the films indicated that the blue (B) to red (R) light ratios of pearl WF (1.07–1.50) were lower than that of the black PE (0.83–1.69) and blue WF (1.94–8.68) regardless of the weather, whereas the difference in red to far-red light among the films was less than 25%. The air temperature at 2 pm of the pearl WF was 0.6–2.4^oC lower than that of the black PE and blue WF in the summer. The plants grown under the pearl WF had an overall increase in the growth of the aerial part, including the leaf area, more than that of the black PE or blue WF, thereby having the most significant root weight at the time of final harvest. Aside from the targeted product, the total chlorophyll content of the ginseng grown under blue WF was maintained at a high level. The results from the experiment summarized that the pearl WF is recommended to increase the root weight of ginseng because it can ensure durability and provide a cost-effective approach for manipulating microclimate properties to promote their growth.