Submitted to: Journal of Environmental Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2011
Publication Date: 3/1/2012
Citation: Fare, D.C. 2012. Evaluation of spectral light management on growth of container-grown willow oak, nuttall oak and summer red maple. Journal of Environmental Horticulture. 30:8-12.
Interpretive Summary: Container grown tree liners are typically marketed by height. Often the trunk diameter (caliper) is too slender to support shoot growth; as a result the trunks are tied to a stake at the seedling stage and the stake is often required up to two years. However, trunk quality is often reduced due to scars on the trunk tissue made by the stakes. Colored shade products have successfully reduced plant height and resulted in stronger shoots with several herbaceous plants. This experiment evaluated the effect of colored shade cloth on germination of willow oak and the height and trunk diameter growth of willow oak, Nuttall oak and summer red maple. The colored shade cloth had no influence on germination of willow oak acorns or height and caliper growth following germination. Overall, there was a lack of strong evidence to support the use of colored cloth for manipulating growth of woody ornamental tree liners.
Technical Abstract: Plant response to blue, red, gray or black shade cloth was evaluated with willow oak (Quercus phellos L.), Nuttall oak (Quercus nuttallii Palmer, Nuttall) and Summer Red maple (Acer rubrum L. ‘Summer Red’) liners. Light transmitted through the colored shade cloth had no influence on germination of willow oak acorns or height and caliper growth following germination. Height, trunk diameter, number of internodes, shoot and root dry weight were generally greater with the species tested when grown under red or gray shade cloth, but were often similar to plants grown under blue or black shade. Height increase of willow oak under red shade was similar to plants grown under blue or gray; however, the average number of internodes was similar with oaks under blue shade and 16% less with oaks under gray shade. Summer Red maples grown under black, blue or red shade cloth were similar in height; however, plants grown under blue shade had 23% less dry weight. Nuttall oaks grown under gray shade had the greatest height increase while the plants under red shade had the largest trunk diameter. The morphology of the species tested was not significantly altered to promote the use of colored cloth during production.