Research evaluating over-the-row tart cherry harvesting was funded in 2008 as a five-year project by USDA’s Research, Education, and Economics Information System.
Headed by Michigan State University horticulturist Dr. Ron Perry, it involves other MSU researchers: cherry breeder Dr. Amy Iezzoni; Dr. Greg Lang, who studies cherry orchard design and orchard systems; Dr. Jim Flore and Phil Schwallier, both experts in growth regulators; economist Dr. Susanne Thornsbury; agricultural engineer Dr. Dan Guyer; and Dr. Nikki Rothwell, coordinator of the Northwest Michigan Horticultural Research Station at Traverse City.
In 2009 and 2011, three plantings were made at the Northwest station with the idea that they’d be used as test orchards for production systems that did not use trunk shaker technology and would be suited to over-the-row harvest. They would supplement Iezzoni’s experimental rootstock and variety trial plantings at the Clarksville Experiment Station. The plantings at the Northwest station include genetic dwarf and compact tart cherry selections in a high-density spacing of 4.9 feet by 13.1 feet.
Six scion varieties
There are six scion varieties in one of the new Northwest plantings. Two of them, Carmine Jewel and Crimson Passion, are dwarf varieties from the University of Saskatchewan, where Dr. Bob Bors had been working for some years to develop cold-hardy tart cherry varieties that are bushlike and can be harvested with the same machines used to harvest the berry-type fruit of haskaps and saskatoons. In that very cold climate, Bors found that bushlike cherries tolerate winters with less winter injury. And being able to use the same machine to harvest three crops in three different seasons made economic sense.
The other four varieties in the planting are conventional Montmorency; MSU 27 12 (2), a variety bred and being tested by Iezzoni; and Nana and Tamaris, two varieties from eastern Europe. These are being grown on Mahaleb rootstock.
In a second planting, rootstocks are being evaluated for their effects on the Montmorency variety. The rootstocks are Gisela 3, 5, and 6, and Mahaleb. Montmorency is also being grown on its own roots. Two training systems are being tested, Rothwell said: the bush type and central leader.
In a third planting, five elite selections from Iezzoni’s tart cherry breeding program are being evaluated.
“The trees look beautiful,” Rothwell said. “We are irrigating and fertigating them, and they are growing well.”
Rothwell would like to see grant money directed toward helping growers test the system in their own orchards. “We’d like to get this into growers’ hands,” she said. “Let them help figure out how to make it work.”
Some growers are already participating.
Harvester testing is continuing, most often in the orchards of growers cooperating with the university researchers. Tests have been conducted at Cherry Bay Orchards, Hartford, Michigan, using a new style of berry harvester, the BEI 3000, fabricated by BEI International, which has a long history with blueberry equipment.
Initial harvesting trials were conducted in 2008 at the Clarksville research station using a machine now named the Oxbo (formerly Korvan) 7624. The following year, tests were again run at Clarksville using a different Oxbo International machine, and it was also used at H & W Farms near Belding, Michigan. George Wright and his partner Timothy Heffron had a four-year-old planting of Montmorency cherries that was harvested using the Oxbo 9000.
Interest in the system is continuing to build.
This winter at the Great Lakes Expo, Jacob McManus will make a presentation to growers on his economic model that will help growers decide when it pays to pull out an existing traditional system and change to high-density plantings made for over-the-row harvesting.
During the Northwest Michigan Orchard and Vineyard Show in Traverse City January 21-22, Polish ag engineer Dr. Ryszard Holownicki, head of the Horticultural Engineering Department, Research Institute of Horticulture (Instytut Ogrodnictwa), in Skierniewice, Poland, will make presentations about the work at their institute.
Also two training systems—the bush and central leader—are being tested in the second planting.