|Systems approach-based mitigation of postharvest diseases to overcome trade barriers for Washington apples|
C. L. XIAO (1). (1) USDA-ARS, SJVASC, Parlier, CA, U.S.A.
Speck rot caused by <i>Phacidiopycnis washingtonensis</i> and Sphaeropsis rot caused by <i>S. pyriputrescens</i> were reported as new postharvest fruit rot diseases in Washington State in the mid-2000s. Both diseases can cause significant postharvest losses of fruit if left uncontrolled and the two fungi have been listed as quarantine pathogens to certain overseas markets. The two fungi can cause canker and twig dieback of crabapple (used as pollinators) and apple trees, infect apple fruit in the orchard, and remain latent before harvest, leading to postharvest fruit rots. A series of research has been conducted to determine the sources and availability of inoculum in orchards and timing of apple fruit infection in the field in relation to the development of postharvest fruit rots, and develop pre- and postharvest chemical strategies for control of the diseases. A systems approach-based mitigation to meet export requirements is based on the biology and epidemiology of the diseases and includes a series of pre- and postharvest practices targeting various components of the disease development from orchard to storage and marketing channel. The development of the mitigation measure will be discussed.