NewBiz - Organic innovator tackles corn pests
Date: 20-Sep-02
Country: USA
Author: Samuel Fromartz
"At a farm stand, corn is your No. 1 crop," says Jack Manix,
an organic farmer at Walker Farm in Dummerston, in southeast
Vermont.
For organic farmers like Manix, though, corn has been a
particularly pesky crop - worms seem to like it as much as
humans do. What humans don't like is peeling open an ear of
corn and finding a wiggling worm.
While organic farmers have lived with this problem for
years, a new product has come on the market.
Inspired by farm-folk wisdom and nurtured by technology, it
was developed by a researcher at the University of
Massachusetts. Its aim? To zap the worms organically before
they damage the crop.
When corn earworm moths migrate north, they lay their eggs
on corn silk. The eggs hatch into caterpillars, then wiggle
down the silk strands and, protected by thick husks, take up
residence in the ears.
Conventional farmers spray their crop with chemical
pesticides, often as many as five times, even if it means
they can't go into their fields after application.
Until recently, organic farmers simply crossed their fingers
or said a prayer that the pests wouldn't be too bad during
the season, since they had to face customers at farmers
markets.
"Some customers would be horrified to see a worm," says Jim
Crawford of New Morning Farm in Hustontown, PA, who sells in
Washington D.C. Other customers would simply view the worms
as tried-and-true organic - evidence of a pesticide-free
crop.
But if the infestation was chronic, many farmers would let
the crop wither in the field, since the point was to offer
customers an organic product as good or better than
conventionally farmed produce.
"It was a major problem," says Ruth Hazzard, in the
Department of Entomology at the University of Massachusetts
in Amherst.
FOLK WISDOM
Twelve years ago, she recalled, a New Jersey farmer related
a story from an old timer, who said that farmers would place
a drop of mineral oil on the thin strands of corn silk to
suffocate the young worms before they migrated down into the
ear.
Hazzard did some research on her own and found material to
back up the folk wisdom, from the pre-World War II era
before pesticides became prevalent.
So over several years, with government and foundation
grants, she developed a system to apply oil to the silk.
Hazzard switched to corn oil to meet organic standards and
eventually added Bt, a commonly used soil bacterium that
kills bugs when they eat it.
Students from U. Mass. as well as nearby Hampshire College
developed a gun-like applicator, which can deposit a drop of
the oily potion directly on the silk. It needs to be applied
once on each ear, and takes 8-10 hours per acre.
They named the contraption the Zea-Later, a pun on the
phrase "see ya later!" and Helicoverpa zea, the scientific
name of corn earworm.
"THE MISSING LINK"
When Manix tried out a prototype Hazzard provided in 1997,
the field he tested it on had only a 5 percent earworm
infestation vs. 75 percent in his untreated fields.
"I couldn't believe it," he said. "It was sort of the
missing link for organic corn."
In subsequent studies, the improvement appears to be around
25 percent. In other words, farmers might get only a 50
percent infestation instead of 75 percent rate without the
application.
Crawford, who has been using the system for two years at New
Morning Farm in south central Pennsylvania, went many weeks
with hardly a worm in sight - until September.
The latest problem might have come from applying the oil too
late, since there is a very narrow window during which it
needs to be applied to the corn silk.
Crawford also had some trouble with European core borer
worms, which dig into the ear through the husk, though he
had some success introducing a tiny wasp that eats the worm
eggs.
The troubles are well worth it, since Crawford says he gets
a handsome premium for pesticide-free corn.
"It's a profitable cr
