Conventional airblast sprayers operate in continuous spray mode, so they can’t adjust sprayer flow rate in real time to match canopy conditions. For apple growers, this familiar type of sprayer can do a good job of controlling diseases and insect pests, but it wastes pesticide because much of what goes out the nozzles never hits the target.
Our project is testing a new type of airblast sprayer called the Intelligent Sprayer. It uses lasers to help it “see” where the trees are and how dense the canopy is, then adjusts the spray nozzles to aim the spray accurately. Field trials have shown savings of 30 to 80% on the volume of pesticide applied – without compromising on pest and disease control Another plus for Intelligent Sprayers is that they are commercially available; in fact, you can have your standard airblast sprayer converted to use Intelligent Sprayer technology. But this makeover doesn’t come cheaply. To figure out when, where, and how Intelligent Sprayers can be profitable, we’re taking a close look at the money side.
As the economists on this project, we’ll total up the costs and benefits of converting to an Intelligent Sprayer, using both partial budget analysis and a techno-economic model. We already have experience figuring out cost-efficiency of disease-warning systems for Midwest apple production. This time, we’ll use the Intelligent Sprayer with and without disease-warning systems so we can see the financial projections from using each technology alone as well as together.
The kind of savings we think we’ll see from using an Intelligent Sprayer differ from savings using a disease-warning system. The Intelligent Sprayer saves volume on every spray, so you use less volume and less pesticide per acre. In addition, this could mean less trips to refill the tank, especially when you have a large orchard. In contrast, warning systems can reduce the number of sprays against certain diseases.
To put together a partial budget, we don’t need all of the cost items in the production process. What matters is the ones that differ between the Intelligent Sprayer and a conventional airblast sprayer, and between using a disease-warning system or not. One yardstick we use is the Relative Cost Efficiency Ratio, which is the marketable yield per dollar cost to produce apples in a specific system – for example, Intelligent Sprayer technology - divided by the yield per dollar cost with an alternative system – in this case, a standard airblast sprayer. If this ratio is greater than one, the Intelligent Sprayer is more cost-efficient than the standard airblast.
To figure out the payback period – how many years it will take for the investment in the Intelligent Sprayer to pay for itself - we need to account for several factors (Figure 1): pesticide application frequency; costs of pesticides, tractor and sprayer; and logistics for pesticide application, which include tractor and sprayer speed, and time required for pesticide mixing, sprayer tank filling, and pesticide application. We’ll compare the costs of Intelligent and standard airblast sprayers in field trials under the same orchard conditions. Intelligent Sprayer technology offers some potential labor and fuel savings in refilling the sprayer, thanks to less spray volume applied per acre (and thus fewer tank refills). We’ll also figure in the finances of using warning systems for the diseases fire blight and sooty blotch and flyspeck – with and without the Intelligent Sprayer technology.
Intelligent Sprayer: Less mixing time, fewer refills, less fuel.
Warning systems: Fewer sprays, less fuel, shorter hired labor time.
Major Cost Items:
Sprayer retrofit fee
How long will it take to recover your investment if you adopt the Intelligent Sprayer? Orchard size is likely to be an important factor, with quicker payback for larger orchards, along with orchard layout, sprayer capacity, refill station location, and so forth.
It’s likely to take several years to repay the cost of the Intelligent Sprayer (which is much more expensive than adopting warning systems). Despite the investment and payback questions, these technologies offer new options when deciding how to manage pests and diseases.