UC tests shorter fruit trees to cut labor, insurance costs
By Tim Hearden
DAVIS, Calif. — University researchers think they’ve found a way to help laborers on peach and nectarine farms climb down from their ladders and put them away.
A farm advisor and a plant physiologist are using a four-acre University of California plot near Fresno to test whether shorter peach and nectarine trees can reduce labor and insurance costs without sacrificing fruit quality and yield.
The scientists are planting “semi-dwarfing” rootstocks in various densities in an effort to create “ladderless” orchards. Having laborers pick from the ground would save the considerable time it takes to move and position ladders during harvest.
“This is something I’ve been doing research on since the mid-’90s, working with short trees and trying to get away from ladders,” said Kevin Day, a UC Cooperative Extension farm advisor in Tulare County. “Minimum wages were going up almost annually and people were spending a lot of money, and they were looking for ways to save money. Nobody had a really good feel for how much it would cost to put ladders in an orchard, or two, if you could survive with short trees.
“This new trial is just trying to amalgamate all the things we’ve learned and include the new rootstocks,” said Day, who is working with UC-Davis plant physiology professor Ted DeJong on the new project.
Day said he’s seen labor cost savings of between 25 and 45 percent in preliminary tests of semi-dwarfing rootstocks. Moreover, use of ladders in conventional orchards is why peach and nectarine growers pay about 40 percent more for workers’ compensation insurance than growers who work with shorter crops such as grapes, a UC news release explains.
Conventional peach and nectarine trees grow to about 13 feet tall, requiring the ladders to harvest the fruit. Laborers spend about half their workday setting up, climbing and moving the ladders, the release notes.
Day said the test plot at the UC’s Kearney Agricultural Research and Extension Center in Parlier, Calif., will be large enough to get a more accurate sense of whether shorter trees will work. Developed by breeders at UC-Davis, the new rootstocks will produce trees that grow to 7-8 feet tall.
The trial is part of a larger experiment on best practices for the fruit trees. The researchers will compare yields from a conventional orchard with those of shorter trees that have been minimally pruned, made use of pressure chambers to determine water needs and been treated with compost and nitrogen sprays to minimize nutrient leaching into groundwater, the release explains.
Workers at the Kearney facility “vastly prefer working with the smaller trees,” Day said. And some growers are eagerly waiting to see if the smaller trees are viable.
Bill Chandler, who grows several varieties of peaches and nectarines on his 250-acre Chandler Farms in Selma, Calif., said it costs him $1,400 an acre to thin trees in his conventional orchard.
“Ladderless orchards would be huge for our industry,” he said in the release. “There are so many costs associated with ladders that many growers are switching over to almonds just to stay in business.”
The team will begin planting next spring and expects to have preliminary data by 2016.
UC Kearney Agricultural Research and Extension Center: http://kare.ucanr.edu