WCN Dec e

Continued from Page 71
Fillmore said the goal with organic production is to find
ways to use the tools you have.
Insect pests, nutrition and orchard floor maintenance are
the three main challenges.
Organic walnut growers look to soil health for production
and integrating mechanical weed control into their systems.
Trees that are farmed well produce pretty good yields, Fillmore
said.
Fillmore said the family focuses on soil health in their
orchards, encouraging the growth of beneficial soil microbes
that produce nutrients for sustainable crop production.
Transitioning young trees to organic production is a common
practice, but he said that production can begin to taper
off after a few years unless growers recognize the importance
of soil health in providing for tree nutritional needs.
Navel orangeworm (NOW), codling moth and husk
fly are the main insect pests, but Fillmore said there are a
couple of positives about the organic approach. Not using
broad-spectrum insecticides leads to a higher population of
beneficial insects. Fillmore Farms also utilizes bat houses to
provide habitat for bat colonies that can help reduce insect
populations in orchards.
For husk fly control, Fillmore said timing is important for
efficacy of a spinosad-based treatment. Treatments at $60 to
$150 per acre are expensive and provide less benefit if timing
The largest segment of consumption for organic walnuts is in retail
sales for culinary use.
is off even a day or two.
Codling moth can be treated with BT, but each treatment
is only effective for a few days. Fillmore said codling moth
damage is not as immediately obvious on the processing side,
but CM attacks the hull of the immature walnut, providing
an opening for NOW.
Orchard sanitation, mating disruption and trapping are
Fillmore’s strategies for NOW control. This pest is the toughest
challenge in organic walnut production. He noted that
Peterson traps have been an effective tool to remove female
NOW from the orchard but added that any moderate to severe
NOW problem will require more than one approach to
control in an organic setting. There currently are no organic
sprays that effectively control NOW.
“NOW is a little like Bermuda grass,” Fillmore said. “If
you let it get a start in the orchard, it is much harder to control
later on.”
When it comes to weed control, Fillmore said modified
mowers that work closely around tree trunks are used rather
than herbicides. Choosing to mow weeds rather than use
herbicides also removes herbicide resistance from the list of
grower concerns.
Comments about this article? We want to hear from you. Feel
free to email us at article@jcsmarketinginc.com
72 West Coast Nut December 2021