Cotton plants that take a blast coming
Someday breeders will be able to choose cotton plants that can better withstand wind sandblasting, according to an Agricultural Research Service scientist.
ARS plant physiologist Jeff Baker has been testing the effects of wind sandblasting on cotton seedling growth. His goal is to develop plants that can heal faster and still maintain yields after suffering sandblasting damage.
• Sandblasting beats up little cotton seedlings every spring in parts of Texas.
• High-velocity erosive winds pick up particles of soil that set back plants.
• ARS is working on research to help cotton plants of the future bounce back.
Baker is based at the ARS Wind Ero-sion and Water Conservation Research Unit at wind-swept Big Spring, Texas. He is studying the effects of wind sandblasting not only on stems and leaves, but also on plant roots.
Big Spring is in the heart of Dust Bowl country, where localized dust storms still sandblast crop seedlings — just as widespread dust storms did during the 1930s and 1950s.
The strong wind season begins in November and ends during May each year (a time when tender, young cotton plants are just emerging across the Plains in spring). The erosive winds, often reaching speeds of 25 to 40 miles per hour or more, pick up loose particles of soil. The impact on seedlings is similar to the effects of using a mechanical sandblaster on a plant.
Wind tunnel test
Using a wind tunnel, Baker and colleagues blasted seedlings with sand-laden 30-mph winds. They studied the effects immediately, and also after two and four weeks.
They found over the first two weeks, the seedlings shifted from root and leaf growth to the repair and growth of injured stems instead. By the fourth week, plant growth had returned to normal, once again balancing growth throughout the cotton plant, down to the roots.
Wind sandblasting has similar effects as pruning — the loss of leaves and reduced photosynthesis. But unlike pruning, windblown sand abrasion damage ruptures plant cells, exposing the plant to temporary drought effects induced by increased plant respiration rates and possible damage to the tiny openings on the outer layer of young plant stems and leaves, called stomata.
More tests are needed on the effects of sand abrasion damage on cotton’s net photosynthesis and respiration to understand the physiological mechanisms of plant injury and recovery.
Comis writes for ARS.
This article published in the March, 2010 edition of THE FARMER-STOCKMAN.