Though abscisic acid (ABA) is one of the five major classes of plant growth hormones, it has never really been considered as a horticultural crop management tool because of its high cost. But with recent technological manufacturing advances that have brought down the cost of production, ABA could have potential as a thinning agent for tree fruit growers in the future. For years, uses of ABA were not seriously considered for commercial horticulture. At $670 per milligram (the purchase price from a chemical supplier of laboratories), ABA just didn’t make economic sense for use as a chemical thinner in orchards […]