Steve Tennes, who operates the Country Mill orchard and farm market at Charlotte, Michigan, became convinced several years ago that there was a future in organic fruit production. Today, some of his customers will come a hundred miles or more from Detroit and Chicago specially to buy his organic apples.
But Tennes also realized he needed to know a lot more about horticulture to do it. So he went back to Michigan State University and spent four years, part time, from 2004 to 2007 working on a master’s degree in horticulture.
He was encouraged and helped in his organic plan by Drs. Ron Perry and Jim Flore. (He was also helped financially with two different scholarships administered by the Michigan State Horticulture Society. “It is ironic that now I am the president,” he said. “I came full circle.”)
Tennes began the process of converting existing orchards to organic production, and also began planting trees at higher densities. His new orchards are on trellis wire with trees 4 feet apart, compared to the older orchards on 10 by 18 spacing.
“The new plantings have worked out well,” he said. “What hasn’t worked was trying to convert old varieties to organic. We tried that for six years and finally backed out of converted acreage.”
The new orchards contain all apple scab-resistant varieties—Liberty, Jonafree, Enterprise, GoldRush, Crimson Crisp, Redfree, Galarina, Florina, Novamac, Novaspy, Topaz, and Pristine. And they are planted on fire blight-resistant rootstocks.
Of the diseases, apple scab is the most difficult to control for eastern growers. Most resistant varieties carry the Vf gene, and that has been shown to break down under heavy pressure.
“I try to guard them,” Tennes said. “I cherish their disease tolerance. It’s a gift that needs to be taken care of.” To do that, he carries out a scab suppression program spraying with copper and sulfur.
Do organic customers like the disease-resistant varieties? “They accept them,” Tennes said. In his view, if his customers want to eat apples produced using organic methods, they’ll have to meet him half way.
They seem willing to do that. While most all the fruit grown on the farm is sold through the farm market, some of the organic apples are packed for distribution to stores for fresh sales. He also sells organic apples for processing.
“There are four damaging insects that organic apple growers need to control, and two of them are difficult for organic growers,” he said. The two difficult ones are plum curculio and apple flea weevil.
He uses Entrust (spinosad) to control plum curculio, but he also traps and kills them using black pyramid traps. In addition, he uses entomopathogenic nematodes that kill larvae in the ground.
Oriental fruit moth and codling moth, the other two main insects, are controlled using mating disruption, Entrust, and virus.
Tennes cooperates closely with MSU researchers who are trying to perfect pest control methods for Michigan growers attempting organic fruit production.