Production | Spring 2010
Fine-tune your spray technique.
By Scott Garvey
For faster, safer, cheaper and more accurate spraying, check out what’s new in product and application technology
The concept of applying crop protection products isn’t new — farmers have been doing it for decades. But almost everything used to get the job done has undergone a transformation.
Old flat-fan nozzles, common on sprayer booms for years, have given way to high-performance air induction nozzles that can deliver product metered from a variable-rate controller. These systems control droplet size, minimize drift and deliver greater spray volumes.
That’s just the tip of the iceberg. Producers and custom applicators now have more products to choose from and more ways to apply them than ever before.
To better meet growers’ needs, crop protection companies have even changed the size of containers they package products in. "A couple of years ago we added the mini-bulk and bulk options," says Troy Basaraba, market development specialist for Bayer CropScience. "And we also went to the thousand- and two-thousand-acre totes on a couple of our products." These innovations make handling and loading faster and easier: a real bonus if you have to treat a lot of acres.
But product not only has to be easy to handle, it must also be effective. In many cases, that means preparing custom blends to deal with field-specific conditions, such as herbicide resistance, or targeting a specific mix of weed varieties. Getting the right blend requires a little homework.
Fortunately, custom applicators and retailers have the necessary skills to provide some tutoring. Today, you can have a custom herbicide blend prepared by a retailer. Dry products, often used at a rate of only grams per acre, are ideally suited to doing just that.
"They let you make custom blends that target certain weeds," says Jon Bagley, owner of Westman Aerial Spraying Ltd. near Brandon, MB. "You can create a bag with just enough product for one sprayer load." The water-soluble bags can just be dropped into a sprayer tank without exposing an operator to any chemical.
Although rubber gloves should be worn when handling these bags, there is no need for the precautions normally required when mixing liquids. And there are no containers to wash out. "The only thing left is the wrapper the soluble bag was in," says Bagley. Those can be disposed of at a regular landfill because they are free of chemical residue.
Aside from adding a new level of workplace safety, dry products greatly simplify sprayer filling procedures. "If a customer has 40 acres to spray, then I’ll just make up enough for a 40-acre load. He can just put that whole bag into the sprayer," says Bagley. "We’d have to ask a few questions. But we can build each load for him in those bags."
Dry products are easier to ship and store, too. And they take up less warehouse space; a plus for retailers. Unlike liquids, they don’t freeze, which means they don’t have to be stored in heated buildings. "We’re not going to get rid of liquid products anytime soon, but a lot of new products are going to a dry formulation" adds Bagley. If a dry product spills, it’s much easier to clean up. "You just sweep it up and dispose of it in the proper way."
So far, dry formulations represent only a small segment of the market. But even liquid products are now easier to handle. Chemical handling systems can be used to open and wash out containers, along with introducing product into a sprayer tank at precisely controlled rates. And they can also pump directly from large-capacity totes, which further minimizes worker exposure.
For producers who don’t have the equipment or don’t want to apply crop protection products themselves, numerous custom applicators are willing to take over that task. And custom application offers even more choices: do you want it applied by ground or by air?
High-clearance ground sprayers cover a lot of acres in a short time and leave only a narrow footprint in the field, minimizing crop damage. But airplanes don’t leave any footprint at all. And if fields are muddy, aircraft can easily go to work when ground sprayers are parked waiting for conditions to improve. That may mean the difference between timely application and missing a spray window completely.
Bagley says while ground sprayers usually apply product at five to ten gallons per acre, aircraft can efficiently deliver the same mixes in four to five gpa with no difference in efficacy. "There have been lots of studies on that," he says. In Canada, manufacturers have to prove the prescribed rates of application for both ground and air work adequately so producers should see exactly the same results regardless of whether application was by ground or air.
The reason for the difference in rates, according to Bagley, is that spray droplets applied by aircraft tend to be smaller than from a ground sprayer, mainly because of the turbulence created by the plane. That allows for better crop coverage with less water.
But staying above the crop without leaving damaging tracks in a field may be the airplane’s biggest edge in the air-versus-ground debate. Murray Richardson, a grower in the Brandon area, sees that as a huge advantage. "We used to tramp down two and a half acres in a quarter-section (with a ground sprayer)," he says. In a 40-bushel wheat crop, that amounts to a 100-bushel loss on every quarter.
Factor in the similar cost of ground and aerial applications and those yield losses go a long way toward offsetting the cost of custom application. "The plane is only a dollar per acre more (without yield losses)," Richardson adds. That’s a definite advantage as far as he’s concerned.
A ground sprayer, however, can operate in windier conditions than a plane and still minimize drift. But a plane can cover acres much faster when conditions are good.
"In some niches the airplane fits in very well, applying certain products," says Bagley. "And there is no spreading of disease," adds Jill Lane, executive director of the Canadian Aerial Applicators’ Association. When ground sprayers travel between fields, they can carry diseases as they go.
Although Bagley’s company provides both aerial and ground application services, he has a bias toward airplanes. "Our roots were in aerial application," he says. "We believe the airplane is the better way to go for farmers." And the airplane remains the only choice for some crops, like sunflowers. But where adjacent crops are susceptible to drift, Bagley says he often opts for ground application.
According to Lane, farmers are increasingly finding value in aircraft for crop spraying, particularly in the west. "We’ve seen an overall increase in demand for aerial application across much of the prairies during the past few years." she says.
But whatever choice you make about products or application methods, it has to have a financial benefit, cautions Richardson. "You’ve got pencil it out." And that is one of the few things about applying crop protection products that hasn’t changed. FF
