By Rosalie I. Tennison
Spraying fungicide on potatoes by air offers many benefits.
Perhaps the quickest and easiest manner in which to get a fungicide sprayed
on a potato crop is by air. All it takes is a phone call to a company offering
the service to book time and then wait for the service to be complete. In western
Canada, the size of the fields makes air application feasible and sensible.
Besides the speed at which an entire field can be sprayed, there are other benefits
to air application.
"There are many benefits to using air application," says John Bodie,
who has five airplanes dedicated to spraying at his company, Jonair in Portage
la Prairie, Manitoba. "We don't leave wheel tracks, our droplets are smaller
so we get just as good coverage as ground application, and we can spray 600
acres in three to four hours." His company also has two high clearance
sprayers that are available for custom ground application. Bodie is in the custom
spraying business and he will accomplish the job however a customer wants it
done, but he prefers air.
Several years ago Jonair and other companies, including Ken Kane Aerial Spray
of Minnedosa, Manitoba, commissioned research on air versus ground application.
In the research conducted on Manitoba potato farms, there was a noted difference
between marketable yield and total yield in the comparison. The net effect of
ground sprayer traffic on four affected rows in the field was a 14 percent yield
reduction, using a formula that compared the yield differences multiplied by
the affected rows where the losses occurred. Bodie says that with losses reaching
this level at times, it is easy to see that by removing that yield loss, any
extra custom application costs would be covered.
"The difference in cost between custom ground application and air application
is about one dollar," Bodie explains. For potatoes, he believes air is
better because it takes less time, is not as hard on the crop and is equally
effective in terms of coverage.
Ken Kane agrees. With 17 planes in the air, Kane has a good idea of how valuable
and needed his service is. "Ground spraying takes longer and a grower may
not have time to do it. We can spray 2500 acres using three planes in three
hours, that is a huge saving in time for a grower. In terms of cost, ground
rigs cost a quarter-million dollars, so they aren't less expensive than hiring
an aerial applicator."
Kane adds that wet weather can increase his business because ground sprayers
cannot get on the field when the crop needs to be sprayed. He explains that
he offers next day service if a customer calls and wants a field sprayed. That
kind of turn-around is not always available with custom ground application.
A potato grower who uses a combination of aerial and ground application is
Stan Wiebe, who operates Beaver Creek Farms with his brother, Don, near MacGregor,
Manitoba. He says when their crop is small, they will use their own ground sprayer
to apply fungicides, but when the crop begins to fill in, they call in an aerial
applicator. "There are some practical considerations for using aerial application
on our farm," he says. "We have irrigation, so we time our aerial
application with our irrigation program. Fortunately, our potato fields are
one mile long, so there are no hazards for the planes to deal with when they
come to spray." In addition to planting up to 1000 acres of potatoes, Beaver
Creek Farms seeds 7000 acres of grain, so they do not have time to do all the
fungicide applications on their potatoes. He says choosing air over ground for
the majority of their spraying requirements is a matter of time constraints.
"I know our four ground applications lose us about one percent on yield,
which is small," admits Wiebe. He says the air application does cost slightly
more, but it fits into their situation better.
Bodie admits there are limitations to aerial application in some fields with
hazards, such as trees or power lines, or small fields that would be difficult
to manoeuvre around. However, he believes that air application is a benefit
on 95 percent of the potato acres on the prairies.
Kane also believes there is less chance for disease to spread when aerial application
is used. "Mother Nature can dictate some of the application choices from
making disease present in the first place to the best methods for applying controls,"
he says. "In a year when there is a lot of moisture, using ground sprayers
is difficult and then we get more calls."
The benefits of aerial application are great, including saving yield, but growers
ultimately decide if their operation is conducive to aerial application. -30-