UNIVERSITY PARK, Pa. — High-tunnel growing systems, sometimes called hoop houses, have gained popularity for their ability to enhance growth conditions and extend the growing season of horticultural crops. Now, a team led by Penn State researchers has demonstrated that growers can select various plastic film coverings on the structures — depending on their desired light-filtering properties — to protect plants and enhance their health.
In experiments growing green and purple basil as test crops in 12 high tunnels at the Russell E. Larson Agricultural Research Center at Penn State University Park, the researchers evaluated the effect of four alternative polyethylene films with varying light diffusion and ultraviolet-transparency levels. They documented that the plastic coverings — with varying degrees of light transmission in the ultra-violet, visible or photosynthetically-active and near-infrared ranges — had major effects on the growth of both basil cultivars.