Those of you growing cherries that are sensitive to pistil doubling (e.g., ‘Bing’, ‘Tieton’, ‘Early Robin’) should consider protecting the crop during this period of high temperatures (Figure 1).
Research in Dr. Whiting’s lab at WSU-IAREC showed that flower buds are particularly sensitive to heat-induced doubling during the 4-6 weeks after harvest, which corresponds to the critical stage of pistil differentiation (Figure 2). Temperatures above 101°F for as short as 3 hour period showed 5% increase doubling. The coming days temperatures are expected to exceed 100°F so we recommend deploying a protective strategy.
Management practices to reduce the risk
Among potential protective measures, over-tree evaporative cooling was the most effective and sprayable reflectives are somewhat effective at preventing doubling. Under-tree irrigation is not effective for reducing doubling, and may actually increase doubling.
For more information, contact Dr. Matthew Whiting firstname.lastname@example.org