Organic fruit growers face a number of unique challenges, but there is one solution that can be applied to any orchard or berry crop — ecological balance.
A session on the subject was held Wednesday during Day 2 of the virtual Pasa Sustainable Agriculture conference.
While a panel of industry experts highlighted several challenges faced by organic fruit and berry growers, the most bothersome were insects and disease, often made worse by the impact of climate change.
“The interesting thing about organic is your management of disease and insects. It’s a balance system. You have to depend on the natural balance,” said Jim Travis, an organic fruit grower in Adams County and a retired fruit specialist with Penn State Extension. “Things like location and spacing are very important because organic needs air and light.”
A balance of the two helps kill fungi and prohibit its growth by keeping trees dry, he added.
The Impact of Climate Change
And with the increasing impact of climate change, reducing the habitats that allow fungi, bacteria and diseases to thrive has become critical.
Don Jantzi, an orchard manager with Rodale Institute, said diseases such as summer and bitter rot were once an issue limited to Southern states but have now appeared in Pennsylvania due to climate change.
“Six or seven years ago we didn’t see any bitter rot here, anywhere,” Jantzi said. “Now it’s become one of the most challenging things to deal with.”
Another fungal disease, apple scab, was a problem that Jantzi said he’s been able to control by planting scab-resistant varieties such as Liberty and avoiding highly-susceptible varieties such as Gala and McIntosh.
For those considering a transition to organic, Travis said choosing scab-resistant varieties is the first consideration.
“Scab is very difficult to control organically,” he said.
And when scab or any other disease does appear, it’s important to remove any infected trees or parts of trees from the orchard. Travis said brown rot can be devastating to peaches, and he immediately removes any infected trees from his orchard, in addition to other steps.
“Air circulation and sunlight are very important for peaches, and sulfur is also very good for managing brown rot,” he said.
Eric Rice, co-owner of Country Pleasures Farm in Middletown, Maryland, said he has done away with spraying his blueberries, blackberries, apples and pears by balancing beneficial insects, fertilizer and reducing places that harbor fungal diseases.
He also agrees that it’s important to cut out any blight that appears in the orchard.
“We have 12 acres of fruit, so we’re not very large, but it’s manageable without a spray program,” he said.
As far as weed control in an organic operation, Rice utilizes a mulch of rotted sawdust around his blueberry bushes. He avoids sawdust containing black walnut or red oak, and goes for softwood sawdust because it’s more acidic, which blueberries prefer.
For control of broadleaf weeds, Rice digs them out by hand, but says that’s not a major problem.
“We plant slow-growing fescue between the trees, and if we get a good enough mat, we don’t see a lot of broadleaf growth,” he said.
Jantzi has used wood chips successfully to control weeds, and they don’t seem to attract mice, he said.
Birds are another issue for blueberry growers, and Rice has shifted away from netting, instead focusing on planting early-season varieties.
Rice said on his farm birds such as starlings, cowbirds and robins will feast on mulberries first, then move to cherries, followed by blueberries. By planting early season blueberries, he said, the crop is done by the time the birds have finished with the cherries.
In regard to soil amendments, compost was the material of choice for the growers in this discussion. Jantzi said compost is the only thing he adds to his soil, and he times the application in the fall so it has the entire winter to breakdown.
Travis advises growers to be patient with compost, and cautioned against adding too much. A grower typically won’t see improved growth during the first year after a compost application, he said, but that doesn’t mean the material isn’t working. Compost releases an average of 15% nitrogen each year, with the higher percentage being realized in the first year of application.
“You may not see the growth until the second year, and it breaks down over five years until you get all of that nitrogen,” Travis said, advising to get the material tested to determine the proper rate of application.
“Once you put compost down you can’t take it back. You can get high levels of salts or potassium. You have to test it.”
If manure compost or anything animal-based is used, Stephen Hobaugh, inspection program coordinator with Pennsylvania Certified Organic in Centre County, said there are specific requirements that need to be adhered to in order to follow organic certification. With manure compost applications, he added, the timing of harvest can be affected. There are also restrictions for raw manure applications to consider.
“A time period needs to elapse from when you apply it to field and when you harvest,” Hobaugh said. “A fruit tree, it would be 90 days because the edible portion isn’t in contact with the soil. But there are smaller fruits and berries that can contact the soil, such as strawberries, which need at least 120 days between application of manure and harvest.”