The Rural Voice, 1980-10, Page 32ADVICE ON FARMING
Annual pressure tests for
oxygen - limiting tower silos
There are many risks involved in
growing field crops, but one risk that can
be eliminated is the possibility of crop
deterioration in the silo.
"A leak in the oxygen -limiting silo can
result in rapid spoilage and deterioration
of the stored material." says Hank
Bellman, Ontario Ministry of Agriculture
and Food agricultural engineer. "Control
of air movement is important with any
type of silo, but it is extremely important
with oxygen -limited silos. When you
consider the value of stored crops such as
high -moisture corn. farmers can't afford
to take the risk of a leaking silo."
The only way a farmer can tell if an
oxygen -limiting silo is leaking is to have it
pressure -tested by someone who has the
proper equipment and know-how.
"Ideally, farmers should have the silo
checked every year as part of a regular
maintenance program," says Mr.
Bellman. "If this is impossible, once
every two years is recommended."
Now is an ideal time to have high -
moisture corn silos pressure -tested. Tests
should be conducted when the silo is
empty because the oxygen pumped into
the silo during the test may reduce the
keeping quality of the remianing stored
material. Also. if the silo is not emptied
throughly before testing. leaks may be
masked by the remaining material.
"The best person to test the silo is the
original contractor or supplier," says Mr.
Bellman. "The test isn't complicated. but
it does require an experienced tester and
the proper equipment."
The test is conducted by pumping a
small amount of air into the silo. When
the proper pressure is reached, the pump
is stopped and the pressure is measured
periodically over a length of time. A drop •
in pressure indicates the presence of one
or more leakage points. The next step is
to locate the leaks and correct the
problem.
Mr. Bellman recommends that all
farmers insist on a pressure test before
purchasing a new silo to make sure that
the structure has good oxygen -limiting
capabilities.
Farmers who are unable to get in touch
with their original contractors or
suppliers to conduct tests should see the
agricultural engineers at local offices of
the Ontario Ministry of Agriculture and
Food for assistance.
Stockpile kindling
from the woodiot
Woodlots can provide more than a
picturesque view in the autumn. For wise
farm managers, each acre of forested
land can provide one cord of wood per
year indefinitely. That's supplementary
fuel that many rural people find useful
during winter.
"Conscientious management can
ensure a healthy stand of trees." says
Helmut Spieser, Ontario Ministry of
Agriculture and Food energy manage-
ment specialist. "Improving your woodiot
means thinning the trees every fall when
insects are not bothersome and the
underbrush is dead and dry. The trees
should be marked when they still have
foliage for easy identification."
Some trees should not be felled
because of their historic value or rarity.
For example, trees such as white oak,
American chestnut, and elm. if they
are in good condition, should be pre-
served.
Keeping the natural varieties of the
woodiot maintains the normal soil
balance and helps prevent disease. In
other words. do not strip the forest of one
tree variety.
Scrub growth such as crabapple and
ironwood should be cleared. Trees with
large crowns or short trunks are also
considered nuisances. Diseased or
stunted trees are prime candidates for the
chainsaw. Cut crooked, leaning trees and
those struck by lightning. With proper
thinning, plenty of light is made available
to the remaining trees so that they will
grow quickly. Woodlot management
ensures better quality of your timber.
'Use standard safety precautions when
felling trees," advises Mr. Spieser.
"Take a helper along to assist in clearing
brush for the tree's unobstructed fall."
Deciduous hardwoods, such as rock
elm, white oak, beech, sugar maple. and
shagbark hickory are the best for
producing heat in a stove or fireplace.
Less popular are trembling aspen,
Manitoba maple, white pine, basswood
and white spruce. Green wood should be
alt, split and stacked in a covered pile to
dry a year ahead.
How to catch a bug
Bug traps -you have to be kiddingt
Insect traps aren't the invention of a
practical joker -in actual fact they're
saving Fraser Valley farmers thousands
of dollars a year in insecticide spraying
costs.
Bob Vernon, a BC pest expert who
heads a consulting company called
Monagro, uses 20 -centimetre -square
patches of flypaper to forewarn him if
insect infestations are immiment. With
an early warning, then farmers can be
forewarned and spray their fields to avoid
the plague.
Also, growers who once spent thou-
sands of dollars spraying their crops up to
12 times a year on a regular schedule
now often find fields don't need any
spraying at all.
When baiting his insect traps, Bob
Vernon uses bait which will attract
specific insects. For example, onion fly
traps are baited with sliced onion.
While the expert's traps snare many
insects, his trained eye can discern which
ones spell trouble.
The traps are collected and renewed
every three days. The insects are counted
and the results plotted on graphs, one for
each of the dozens of fields under
Vernon's supervision.
When lines on the graph stray above a
predetermined threshold, then the pest
expert sounds the alarm. The danger
point is reached when there are enough
females to lay damaging quantities of
eggs on the crop.
Gerry Spanger, who owns a 220 -acre
farm where Vernon has set up his field
lab, said the insect trapping program has
substantially cut his pesticide bill, which
was running around $15,000 annually.
This same type of pest management
has been tried in the United States, but
there experts have suffered some em-
barrassing failures.
if his program continues to be
successful, Bob Vernon believes the
general idea could be extended to many
crops. He's now trying to apply the
method to tuber flea beetles and other
pests which damage potato crops.
THE RURAL VOICE/OCTOBER
1980 PG. 31