By Cat Holmes
University of Georgia
The adage that one rotten apple spoils the barrel may hit close
to home for strawberry growers in the coming year. Only in this
case, it’s a few infected strawberry plants that could threaten
a whole crop.
A highly contagious fungus that causes anthracnose (a plant
disease unrelated to anthrax) has infected the plants of a
major supplier of strawberry plugs, (the trays of tiny plants
that farmers transplant to their fields), said University of
Georgia plant pathologist Phil Brannen.
This, coupled with the resulting higher-than-usual demand for
clean strawberry transplants, could make things tough for
Georgia growers. They’re planting next year’s strawberry crop
between now and mid-October.
Anthracnose began showing up in strawberry plug beds in late
August and early September in North Carolina, Virginia, New
Jersey and Tennessee, according to Fruit Pest News, a Tennessee
Extension publication.
Now, Georgia planters are finding the unwelcome fungus in
recent shipments of plugs.
The common source of the anthracnose has been a farm in
Ontario, Canada, Brannen said. However, the plugs grown from
the infected Canadian runner tips may come from several
operations, many in North Carolina.
“First, growers will see marginal burning on the edges of
leaves, which will start to crack,” Brannen said. “This is
irregular leaf spot, the precursor to anthracnose.”
In general, he said, the plants will be pale and stunted. Some
will die.
“In the spring, the inoculum in the leaves will be passed to
the flowers and fruit, which cuts back on production
tremendously,” he said. “Fruit rot begins before you can get to
the market and sell (the strawberries).”
The problem with anthracnose, Brannen said, “is that once you
bring it in, you’ve got it. There’s no cure for it.”
Ideally, growers should carefully inspect all new shipments of
strawberry transplants, he said. They should destroy any plants
showing symptoms of the disease.
“Preventing anthracnose from getting a toehold is ideal,” he
said. “But for some growers, this won’t be an option. If a
shipment looks halfway decent, they’ll have to give it a
try.”
That’s because, this late in the season, it’s hard to find a
new source of clean plants. And “for those whose bread and
butter is strawberries, giving it up isn’t an option,” he
said.
Brannen and other UGA scientists have developed a fungicide
spray program they hope will help farmers pull through. Growers
can learn about the spraying regimen from their county UGA
Extension Service agent.
Not all strawberry growers will be affected.
Farmers transplant strawberries in one of two ways: plugs or
bare-root plants. Plug plants come in trays and have an intact
root ball, like any container-grown plant. They have a higher
survival rate and are easier to work with.
However, plugs cost more than bare-roots, which are young
plants that are simply dug up, placed in a plastic bag and
overnighted to the farmer.
The anthracnose problem so far has been found in plugs. But
most farmers haven’t yet gotten shipments of bare-roots, said
Tift County extension agent Keith Rucker.
Growers in Tift County produce 45 acres of Georgia’s 280-acre,
$4.5 million strawberry crop. Most Tift growers use bare-root
plants, Rucker said.
Unlike plugs, bare-root plants must be planted almost
immediately. So most south Georgia growers haven’t yet received
the shipments they will plant this fall.
“People planting bare-roots should be on the lookout for
anthracnose,” Brannen said. “Although we don’t think the
problem will be as severe in bare-rooted plants, we’re
concerned that anthracnose could still come in on these plants
as well.”
(Cat Holmes is a news editor with the University of Georgia
College of Agricultural and Environmental Sciences.)
