Jun 24, 2021When and how to reduce doubling in sweet cherry
Profitability in sweet cherry (Prunus aviumL.) production will depend on growers’ ability to produce superlative fruit and maximize packout. A significant cause of cullage (and therefore lost revenue and higher packing/sorting expenses) in several important cultivars is polycarpy (i.e., multiple pistils, or simply ‘doubling’).
Our own research has shown that doubling may be as severe as 50% in a susceptible cultivar like ‘Tieton.’ Clearly, the potential losses from doubling are economically significant.
Research from Japan showed a clear role of high temperature during the previous season (i.e., while flower buds are developing) on incidence of doubling. At Washington State University in Prosser, the sweet cherry physiology program has been investigating the causes of multiple pistils and pragmatic means for reducing this disorder in cultivars common to the U.S. sweet cherry industry.
Key findings from our research indicate that
- Cultivars are asynchronous in floral organ differentiation
- Early-maturing cultivars exhibit advanced differentiation vs. late-maturing cultivars
- Peak susceptibility to doubling is between four and six week after harvest
- Consider initiating preventative treatments at air temperature of 95+
- Over-tree evaporative cooling shows greatest potential for reducing doubling
- Shade and reflective coatings can also be effective
- Do not use under-tree microsprinklers for reducing doubling
For more information see When and How to reduce doubling in sweet cherry
– Matthew Whiting, Washington State University Horticulture
The “squid’”apparatus used to cool and heat tissue by forced convection. Photo: Matthew Whitting/WSU