Most people know that plants need warm temperatures and light to survive. Too much of a good thing can cause problems. Excess light, combined with high temperatures, can result in disruptions to plant systems, particularly photosynthesis. Short term changes in temperature are more damaging, since plants do not have time to adapt.
Crops grown in open fields are subject to adverse environmental conditions. They receive more light than needed for photosynthesis, and are subject to a range of temperatures. With increasing temperatures, the conversion of light to sugar is impaired. This phenomenon is known as photoinhibition. At higher temperatures, photoinhibition begins at lower light intensities.
With photoinhibition, damaging free radicals (ROX) are formed that damage membranes and other cell components. This damage is repaired through respiration
Under stress, crops produce less carbohydrate, and consume the reminder to repair damage, limiting what's availale for fruit yield and quality. Limiting grower financial returns.
The relationship between temperature and light intensity in contributing to photoinhibition is diagramed on the left.
Screen™ Duo: The Science
Screen Duo brings two modes of action to protecting crops from environmental stress. Screen™ Duo applications form a particle film that protects crops from damaging heat and radiation. The film reflects damaging UV and infrared radiation, while allowing the right amount of visible light to reach plants. By keeping plants cooler and reducing harmful radiation, photosynthesis is maintained longer.The second protection comes from activating the crop's inherent protective mechanisms against damaging reactive oxygen species (ROX, free radicals). Since photoinhibition is reduced,and the protective biochemistry increased, there is less cellular damage due to free radicals. This means that Screen™ Duo-treated crops have more energy for crop growth and to make fruit larger and convert to sugars. In addition, permanent damage, manifested as sunburn damage is greatly reduced due to the temperature and light improving affects of Screen™ Duo.
Screen™ Duo treatment can also improve crop water status. By reducing canopy temperature, the amount of water used for cooling by evapotranspiration is reduced. This leaves more water available for keeping stomates open, allowing better leaf gas exchange. Recent test results demonstrate less water removal from soil by Screen™ Duo-treated plants. See Water Savings for details.
Crop Stress: Beyond Basics
Since the plant cannot photosynthesize, there are fewer carbohydrates available for growth of stems, roots, or to provide energy to developing fruits. In addition, the light that is absorbed by the leaf results in the production of free radicals that cause damage to the membranes and other structures in the chloroplasts and cells. Not only is less carbohydrate produced during the day, but the plant must use available energy sources to repair the damage.
In extreme instances, damage cannot be repaired, and the rate of photosynthesis can be permanently reduced.
