Maximum Yield USA 2009 June | Page 22

MAX facts hydroponic news, tips and trivia Lettuce Carotenoids Affected by UV Light in Greenhouse Recent studies have found that by growing green leaf lettuce in a greenhouse during the winter under the proper ultraviolet light can boost their levels of carotenoids, biological antioxidants that protect cells and tissue from damage. When regularly consumed from green leafy vegetables, carotenoids may help reduce the risk of cataracts and macular degeneration later in life. Plants grown in the field express beneficial chemical compounds, thought to be a means to protect themselves from the effects of UV radiation. The role of light exposure on these compounds was examined on eight green and eight red leaf lettuce varieties. They each received either supplemental ultraviolet-A (UV-A) light, both UV-A and ultraviolet-B (UV-B) light or no UV (receiving only regular light). The green leaf lettuce varieties carotenoid concentration levels were greatly increased when supplemented with UV-A plus UV-B, while the compounds in the red varieties were slightly but significantly reduced. (Source: www.ars.usda.gov/is/pr/2009/090223.htm) Flairform Grower’s Guide Do you know the best way to clone your favorite plant? The Flairform Grower’s Guide can help you. Concise information on lighting, ventilation, pH, system design, diseases, pests, cloning, conductivity, nutrient technology and much more is available in the Flairform Grower’s Guide. Ask for a free copy at your local grow shop or download it for free at www.flairform.com Flairform - Water treatment specialists and horticultural consultants since 1966. 22 MAXIMUM YIELD USA - June 2009