Abscisic Acid: A Potential Treatment for Reducing Leaf Wilting In Potted Bedding Plants

Water deficit stress during postproduction transport and marketing reduces the saleability of many bedding plants.  This problem arises from excessive water loss during extended periods of shipping at elevated temperatures and limited watering of plants during subsequent retail display.  In the present study, we evaluated the efficacy of abscisic acid (ABA) treatment to reduce the visible effects of water stress in potted flowering New Guinea Impatiens and zonal Geraniums.  In the first experiment, plants at commercial maturity were sprayed to runoff with 0, 5, 10, 20, 50 and 100 mg L^-1 ABA and subjected to simulated shipment in boxes for 2 days at 20 °C.  In a second experiment, plants were sprayed with 100 mg L^-1 ABA prior to simulated shipment or an actual 3-day commercial shipment between Overton, Texas and Davis, California.  All plants were watered once after shipment and then were held at 20 °C for 4 weeks for evaluation of treatment responses.  Treatment with ABA greatly delayed the onset to visible leaf wilting for impatiens but not for geranium.  ABA treatments were not phytotoxic to plants and did not affect flower longevity.  Our findings provide support for expanded testing of ABA and other osmoticums as a potential postproduction treatment to delay leaf wilting in bedding plant species.

The authors would like to acknowledge funding from the Federal IR4 Program.