Courtesy Washington State UniversityAn automated freezer sampler exposes cherry and apple flower buds to different cold temperatures to gauge their response.Researchers in the Pacific Northwest are trying to develop a more accurate way to predict how new apple and cherry varieties handle spring-time frosts.
The work, led by Washington State University AgWeatherNet director Gerrit Hoogenboom and research associate Melba Salazar-Gutierrez, will ultimately yield updated cold-hardiness charts for apples and sweet cherries, according to a news release.
Historical cold hardiness data, which is still used today, was based on work conducted 30 or 40 years ago.
So far, little is known about the hardiness of new cultivars under local weather conditions.
The flower bud's growth stage also plays into frost susceptibility.
The historical data was not as specific as new systems.
Researchers simply made observations and took samples of buds and flowers after freezes to determine injury.
Hoogenboom, Salazar-Gutierrez and the AgWeatherNet team studied red delicious, gala and Fuji apples as well as Bing, Chelan and Sweetheart cherries beginning in February.
They collected samples from the university's Roza Research Farm and C&M Orchards near Prosser, Wash., to test temperatures ranging from -40 to 30 degrees Fahrenheit.
A new measurement system in the works uses an automated freezer sampler, which exposes buds to different durations and controlled cold temperature combinations.
The vending machine, as it is nicknamed, was developed by John Ferguson, a staff member at the Irrigated Agriculture Research and Extension Center in Prosser who developed a cold-hardiness prediction model for grapes.
The AgWeatherNet team plans to continue collecting samples from new orchards for two more seasons before developing a model for growers.
The updated cold-hardiness charts will show critical temperatures for each stage of spring bud development for cherries and apples.
“This is a very important tool for growers who are monitoring their individual apple and cherry orchards for appropriate crop management and activation of frost protection systems," Salazar-Gutierrez said in the release. "This will allow for better planning to improve fruit quality, enhance yield and ultimately increase net returns."