Growers Learn about High Tunnels, Organics, Pruning,
Staking and More
The Tomato Magazine
One of the largest groups of tomato growers in the history of the
event was in attendance at the 2006 Great Lakes Fruit, Vegetable& Farm
Market Expo tomato session, held Dec. 5 at the DeVos Place Convention
Center in Grand Rapids, Mich.
Ron Goldy, district agriculture (vegetables) educator, Michigan
State University (MSU) Extension, moderated
the packed session which drew guests from all
over the United States, particularly the East
Coast, as well as Canada.
Session speakers included: Ed Weaver of
Weaver’s Orchard, a fourth generation family
farm in Berks County, Penn.; Dale Mutch,
an extension specialist with the W.K. Kellogg
Biological Station, MSU; Fred Leitz Jr., with
Leitz Farms LLC, Sodus, Mich., an organic
farm; and Stephen Olson, a tomato researcher
with the University of Florida, North Florida
REC, Quincy, Fla.
High Tunnel Tomato Production
Ed Weaver touched on his recent experiences
with high tunnel tomato production. The
farm’s primary crop is apples but, like many in
agriculture today, the grower has been branching
out into other fruit and vegetable crops,
including tomatoes. The farm’s on-site market
has become a primary sales outlet. The farm
also offers a “pick your own” option for crops
such as blueberries, strawberries and brambles
and also markets peaches, apricots, plums, nectarines,
cherries, apples and pears.
“After numerous crop losses to our sweet
cherries—due to birds and other problems—we
were searching for a way to protect the crop,
and in the spring of 2003 discovered the
Haygrove high tunnel,” Weaver told the group.
The first tunnels were constructed over existing
The following year (2004), as the family
became aware of the potential for growing
other crops under high tunnels, one-fourth acre
of tomatoes was planted.
“In 2005 and 2006, we planted 700 tomato
plants in a new three-bay Haygrove structure
that was 120-feet long,” the speaker explained. “Each bay
is 28 feet wide with fi ve rows
planted per bay. Plants are two feet apart. We
also planted small numbers of plum tomatoes,
grape tomatoes, hot peppers and eggplants.”
Raised beds were formed and drip tape buried
prior to laying a black fabric weed barrier,
he detailed. The rows were 4.5 feet apart, and
plants were placed two feet apart.
One row was left open in the middle bay to allow space for a
small sprayer to do its job.
The first of the tomato plants were planted on April 18, Weaver
said. These included 200 Mountain Spring and 100 BHN 589 plants
in 4-inch pots. On May 2, 150 Mountain Fresh, 50 Sebring, 50
Carolina Gold and 50 Health Kick plants were planted.
The plants were staked with 4-foot wood stakes, he said, and
were tied with tomato twine throughout the season. Trickle lines
were used for irrigation and fertigation. Leaf analysis was done two
times during the season; the reports were used to adjust nutrient
“For pollination, we walked through occasionally with a leaf
blower,” the speaker said. “Other times, we went through
stakes. We also placed bumblebee hives in the tunnels when we were
finished using them in other crops.”
Combinations of Bravo, Kocide, Manex, Tanox and Curzate were
used for disease control, Weaver said. Insects were controlled with
Lannate, Provado, Danitol and Acramite.
“Our most difficult pests were thrips and mites,” he noted. “Our
structure is located at the edge of our property where a neighboring
Christmas tree farm is host to many insects, and it seemed that every
time the thrips were wiped out, they were back in a few days.”
As for the 2004 crop, Weaver said he harvested 556 twenty-five-pound
boxes of tomatoes, or about 18.5 pounds per plant
(approximately 2,800 boxes per acre). Quality was split: half No. 1
grade and half No. 2.
Income levels have improved as the family gained experience and
the markets improved. The 2005 crop averaged about $12 per 25-pound box;
the 2006 crop averaged $15.
One production challenge, the grower said, has been dealing
with excessive plant growth. Plans are to reduce the number of rows
inside each tunnel by one to allow more room for air circulation and
for moving equipment through to do the spraying, Weaver said.
Organic Production Presentation
Dale Mutch shared organic tomato research conducted at the
MSU Southwest Michigan Research and Extension Center. He and
colleagues Ron Goldy, Virginia Wendzel and Todd Martin have been
looking at various cover crops aimed at boosting organic tomato
The highest above ground biomass in the fall of 2005 was collected
from oilseed radish (OSR) without compost. There was no
difference between OSR with compost and oriental mustard (OM)
with or without compost. Rye produced more aboveground biomass
as compared to hairy vetch with or without compost. All cover
crop treatments, except hairy vetch, reduced weed biomass, Mutch
reported. Fall applied compost did not infl uence cover crop or weed
In the spring of 2006, OM provided the lowest weed biomass for
all treatments. Rye biomass increased in the spring while providing
good weed control. Hairy vetch increased biomass in the spring but
never out-competed the weed biomass. All cover crop treatments significantly
reduced weed biomass as
compared to the control (no cover crop), the
“Dr. Goldy recommends that organic
tomatoes be picked at less than vine ripe
so they have less time to be exposed to
disease organisms and other potential damage
(cracking, insects, etc.),” Mutch added.
“They should be harvested just as they begin
to change from green to red. Internal ethylene
will cause them to continue to ripen off
the plant, but with less exposure to potential
Following Mutch, Fred Leitz Jr. reviewed
some of the challenges he walked through
in order to be certifi ed as an organic tomato
grower. There defi nitely was a learning
curve, he acknowledged, noting that he now
feels greater confi dence than he did at the
One of the advantages of going organic
was reduced chemical costs, he said.
However, most, if any savings, were probably
offset by additional hoeing and hand
weeding costs, he admitted.
“Would I do it again (certify to grow
organically)? Yes,” the grower said. “Would
I increase acreage? Probably,” he smiled.
Value of Proper Pruning and Staking
The UF’s Stephen Olson addressed
two topics, “Tomato Pruning and Staking” and “Physiological,
Nutritional and Other Disorders of Tomato Fruit.”
While the cost of pruning ranges from $0
to $40 per acre and comprises a “very small
part” of total production costs, it can have
a “very large impact on yield and quality,” Olson stressed.
“The degree of pruning is variety
dependent,” the speaker said. “With weak
determinate varieties such as ‘Solar Set,’‘
Equinox,’’Solar Fire’ and plum types,
only minimal pruning is necessary. With
these varieties only the ground suckers
(those located at the cotyledons) need to be
removed or none at all. Heavier pruning,
especially to the fork, with these varieties
will result in signifi cant yield losses and can
lead to increased sunburned fruit, blossom
end rot and cat facing.
“With more vigorous determinate varieties
such as ‘Agriset 761,’ ‘FL 91’ and ‘FL
47,’ heavier pruning such as removal of
ground suckers plus two additional suckers
may result in increased yields and fruit size,”Olson explained.
Staking increases yield and improves
fruit quality by keeping plants and fruit
off the ground, the speaker said. It also
improves spray coverage and allows better
air circulation so plants dry off quicker.
Staked tomatoes are also much easier to harvest
and less damage is done to the vines.
The full text of Olson’s two presentations
will be reported in upcoming issues of this
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