Leskovar noted vegetable plants often suffer transplant shock because of an imbalance between water loss through transpiration and water absorption through the roots, typically causing plant wilting. He added that windy conditions or high temperatures can accelerate water loss.
"Abscisic acid closes the stomates and reduces water loss through transpiration, preventing further moisture loss in times of low water availability," he said.
Research efforts to date have shown that external application of abscisic acid to cabbage, watermelon and pepper transplants had reduced undesirable excess shoot growth during plant development in the greenhouse environment, Leskovar said. They also show that its application on pepper, tomato and artichoke seedlings was superior to that of other commercial "film-forming antitranspirants" in improving overall plant water status.
"Practices that reduce plant transpiration have the potential to enhance stand establishment, thus conserving soil moisture and reducing irrigation frequency," Leskovar explained. "Abscisic acid appears to be useful for conditioning vegetable seedlings to withstand temporary stress from water deficiency and to improve stand development under stressful field conditions."
He said vegetable transplants quickly recovered their water potential, stomatal efficiency and photosynthetic rates, and resumed their growth after a short period of water stress in response to the external application of the hormone.
Leskovar added that the work he and his fellow researchers have been doing has been supported through the interest of the industry and cooperation with commer
|Contact: Dr. Daniel Leskovar|
Texas A&M AgriLife Communications