Acetic acid is a low cost antitranspirant that increases begonia survival under drought stress

Low doses of acetic acid (10-40 mM) have recently been shown to protect diverse crop plants from drought when grown in pots, but it has not previously been evaluated for any horticultural applications. Here we show that 6-day acetic acid treatments significantly reduced tray evapotranspiration in Begonia xhybrida, with a dosedependent response, and this was sustained for more than 3 weeks of watering without acetic acid. The highest dose (38 mM) did lead to a significant reduction in flower number, but 20 mM acetic acid had commercial potential with significantly lower water use without a reduction in flowering. A low dose of 10 mM acetic acid significantly increased plant survival after 3-4 weeks of water withholding, compared to both higher doses and the 0 mM control. This delayed mortality by similar to 9 days, 7x longer than current commercial antitranspirants in begonia, identifying an additional potential value for production prior to shipping to retail stores. These doses were estimated to add <0.6% to retail begonia costs, even using a diluted food-grade consumer vinegar product, opening the door to low cost antitranspirant use within the potted bedding plant industry.