By Nikki Rothwell
Special to the Record-Eagle
---- — Before 2012, there were likely not many people outside the cherry industry that knew Poland was the world's largest commercial producer of tart cherries.
But after this difficult season, this former Communist country is becoming better known for its fruit. Following the loss of the Michigan tart cherry crop, Polish cherries have been imported to fulfill many of the standing contracts for 2012. Cherry Republic has been flying the Polish flag all season; the company purchased Polish fruit in order to continue to make its wide array of cherry products. On the education front, we will be hosting a Polish researcher at the 2013 Northwest Orchard and Vineyard Show, Jan. 21-22.
At this year's show, Dr. Robert Holownicki will be our featured speaker. He is the head of the Horticultural Engineering Department at the Research Institute of Horticulture in Skierniewice. His main research interests are fruit production mechanization, spray application technique, tunnel sprayers, spray drift and precision agriculture. He is also the deputy chairman of Agriculture Engineering Committee of the Polish Academy of Science.
We have asked Dr. Holownicki to speak on his work with high-density tart cherry systems. In Poland, some growers are planting tart cherries on more dwarfing rootstocks, which allows for many more trees per acre (600-plus trees to an acre). In Michigan, we are planting tart cherries on standard rootstocks, which produce larger trees, at roughly 130 trees per acre.
There are many advantages to growing high-density orchards on dwarfing rootstocks: trees produce at an early age and reach peak production much sooner than trees on standard rootstocks. These plantings may also affect the efficiency of production, improve fruit quality and may be more easily harvested.
Apples and sweet cherries are already grown using these more modern systems, and we are interested in hearing from Poland about their advancements in high-density tart cherry systems.
However, to move to a high-density system in tart cherries, the proposed changes in orchard layout will likely require changes in harvest mechanization. Dr. Holownicki will also present his research on the current technologies that mechanically harvest Polish cherries.
The Michigan cherry harvester, also called a shaker, moves through the orchard, stops and shakes each tree at the trunk. The Polish harvester, on the other hand, progresses through the orchard over the trees and continuously removes the fruit without shaking each individual tree. This change in harvesting technology has great appeal for Michigan growers.
Inviting Dr. Holownicki to speak at our annual show is a perfect pairing with our current work here on the home front. We have three research plantings investigating the horticultural side of producing high-density tart cherries at the Northwest Michigan Horticultural Research Center. We have also been testing alternative mechanical harvesters, and so far, we have looked at many different types of harvesters in the past three years: blueberry, citrus, grape and even olive.
Much of our research here in Michigan shows promise for our industry, and we look forward to hearing more about the latest in tart cherry research from our Polish friends.
Nikki Rothwell is Michigan State University Extension district horticulturalist and coordinator of the Northwest Michigan Horticultural Research Station.