Chemical Control Alternatives
General Safety with Insecticides
The supervisor must explain to employees, in detail,
how to handle insecticides and insecticide-treated seedlings in a safe
manner. Employees must know what to do in case of an accidental contamination
of skin and clothing or if symptoms of pesticide poisoning appear. The
supervisor must not only provide this information, but make certain that
employees work in a safe manner. The supervisor should stress the need
to wash hands before eating, handling cigarettes or chewing tobacco, performing
bodily functions, or before leaving the job. Wash basins, hand washing
detergent, water, and towels must be provided at the job site. Torn -gloves
must be replaced immediately, and workers with blisters and open sores
on hands must be given jobs that do not involve handling insecticides
or treated seedlings.
Imidan Top Dip (Imidan 50W)
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Treatment. - The tops of seedlings,
down to and including the root collar, are dipped in an aqueous suspension
of 4 percent active ingredient Imidan. An adjuvant-either Plantgard or
Nu-film 17 mixed at 2.7 percent (14 ounces per 4 gallons, or 27 ml per
liter) by volume-is optional, but recommended in "hot" areas
or if high rainfall is expected. (Imidan can also be used as a post-planting
spray. See information under Dursban Spray.)
Operational procedures. - Dip seedlings in
loose bunches in the suspension for 10 to 15 seconds, ensuring good coverage
of the lower stem (figure 7). Dipping can be done at the nursery prior
to packing seedlings or at the planting site prior to planting.
Precautions.- Dip must be freshly mixed daily.
Do not let it stand overnight. Agitate the dip frequently to keep the
wettable powder in suspension.
Figure 7. - Pine seedlings may be dipped at the nursery prior to packing
or in the field prior to planting.
Seedlings must be dipped in loose bundles. Dipping whole,
tightly packed 9 open-ended bundles of 500 to 1,000 seedlings is not recommended
because the insecticide will not penetrate and coat the entire lower stem
of all the seedlings. The effect of Imidan on the root system has not
been determined, so avoid covering roots with this insecticide.
Roots may dry excessively when seedlings are dipped at
field sites. Therefore, dip in the early morning, before wind and temperature
increase. Treated seedlings should be heeled-in or returned to a moist
atmosphere in polybags or bundles as soon as possible.
Hand planters can use either planting bags or planting
buckets. Water in planting buckets must not go above the root collar.
Disposable polyethylene bag inner liners could be used in buckets and
bags to prevent a buildup of insecticide.
Safety. - During the mixing of Imidan
50W, a respirator, goggles, liquid-proof coveralls or apron, rubber boots
and rubber gloves must be worn. Imidan 50W is a wettable powder which
should be wetted thoroughly with a small amount of water to make a slurry
before adding the total amount of water. The powder will puff up out of
the container and be carried by the slightest breeze during this operation,
so it is imperative that a respirator and goggles be worn during mixing,
and that other workers stay well away from and upwind of the mixing
During the dipping operation, a face shield should be
worn to protect the eyes and face from splashing. Rubber gloves, apron
or liquid-proof coveralls and rubber boots should also be worn.
Immediately after dipping the seedlings - whether in
the nursery or in the field-place them on a tray or shallow container
to catch the excess insecticide. This will prevent a buildup of toxic
wastes in the area and the excess dip can be reused. Catch additional
drippings with a disposable absorbent. When Imidan dip is spilled on nursery
work tables and floors and allowed to dry, a dusty toxic residue results.
This type of residue should be prevented because it might be inhaled.
Planters should wear rubber gloves.
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Treatment. - At planting time, broadcast Furaden
granules (10 grams or I teaspoon for 10G; 7 grams or 3/4 teaspoonful for
15G) in a 6-inch (15 cm) radius circle around the base of the seedling.
Cover the granules with a light layer of soil or incorporate them into
the soil. You may also apply granules in the planting hole at a reduced
rate of 2to3gramsof 10G(1.3to2.0g of 15G).
Operational procedure.-The granules can be applied
by the planter or a second worker who is following behind. The granules
can be applied with a scoop or metered out by an applicator attached to
the planting bar (figure 8). A granule applicator on a planting machine
could be devised.
Precautions.- Granular Furadan at rates
higher than the recommended dosage can burn the foliage and even stop
growth. Therefore, take care to apply the correct amount. Do not exceed
10 grams of 10G (7 grams of 15G) per seedling when broadcasting. Brown
tips on old and first flush foliage may occur with the above rate of Furadan,
but this is not serious and it will not affect growth rate or survival.
If Furadan is placed in the planting hole, no more than 3 grams of 10G
(2 grams of 15G) should be applied to prevent harmful effects. Test planting
hole treatment on a small scale in order to check out any damage to the
seedlings under local soil and climatic conditions.
Safety. - Open the bags and load granule
reservoirs in an open, well-ventilated place. Take care not to inhale
any Furadan dust. Persons handling and applying the granules should wear
rubber gloves and goggles. Dispose of empty bags in a proper manner.
Furadan Root Dip (Furadan 4 Flowable)
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Treatment. - Dip or spray seedling roots
with a kaolin clay water slurry containing 1 percent active ingredient
Furadan flowable formulation.
Operational procedure.-The roots of the
seedlings can be dipped or sprayed prior to bundling or bagging at the
nursery, or they can be sprayed in the polybag. Dipping can be done in
the field before planting. Under normal cold storage, Furadan should remain
Figure 8.- Granule dispenser attached to the planting bar for surface
or in-hole application of Furadan granules.
Precautions.- The Furadan-clay slurry
suspension can be used for 2 to 3 days if the pH is 7 or below. The insecticide
will break down more rapidly if the pH is greater than 7. Agitate the
suspension thoroughly if it is held overnight; also stir it frequently
during the day. When seedlings are dipped at field sites, be sure the
roots do not dry out. (See "Precautions" under Imidan Top Dip).
In hand planting operations, planters should use planting bags instead
of buckets so the insecticide is not washed off the roots. Polyethylene
bags can be used as disposable inner liners to prevent contamination of
Safety. - When treating seedlings at the
nursery, take care to contain the slurry and prevent spills. Spray the
roots inside the polybags. Use low pressure to avoid fine droplets, which
could be inhaled. If roots are dipped, be sure that the excess slurry
drains back into the dipping tank or is absorbed by material in the bundle
or polybag or material which can be disposed of periodically without contaminating
work tables or the floor. Any spillage that is allowed to dry on nursery
floors or work tables will lead to a dusty toxic residue that might be
inhaled later. Workers exposed during the application and handling operation
must wear face shields, liquid-proof coveralls, rubber gloves, and rubber
Persons handling treated seedlings during the planting
must wear rubber gloves and face shields. Take care to prevent spattering
of the slurry by disentangling roots before placing seedlings in planting
bags or bins of planting machines. Used seedling bags should be disposed
of in a proper manner.
Dursban Spray (Dursban 4E)
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Treatment. - Spray the stems of seedlings to the
point of runoff after planting, with a 2-percent active ingredient aqueous
Operational procedure. - Spray seedlings with
low pressure back-pack sprayers (figure 9).
Safety.- Workers should wear liquid-proof
coveralls or aprons, rubber boots, goggles, and respirators when mixing
spray. They should wear rubber boots and rubber gloves and stand upwind
Figure 9.-Backpack sprayer for post-planting treatment of seedlings with
Dursban or Imidan.