Introduction
Investing in an optical sprayer for horticulture is not a straightforward financial decision. Compared with a conventional boom sprayer, the upfront capital cost is substantially higher, often by an order of magnitude, and most commercial systems require an annual software or service subscription to operate. Despite these barriers, adoption is accelerating, and many growers who have made the investment report very positive outcomes.
To help clarify when and where this technology makes financial sense, I developed a calculator to estimate the return on investment (ROI) of optical sprayers under a range of production scenarios. The goal of this tool is not to promote the technology, but to provide growers and advisors with a structured way to evaluate whether it fits their specific operation.
Note: This calculator was designed for onion and carrot production in Ontario, Canada. Model parameters can easily be adjusted reflect other production systems. However, if you need assistance making these changes you can contact me by email.
New versions may be uploaded as the calculator evolves through experience and based on user feedback, so check back. You can download Version 1.0 (January 2026), HERE.
How to use the calculator
At first glance, the calculator may appear overwhelming because it requires a fair amount of information to be entered. This is the minimum data required to reflect real-world conditions while avoiding an oversimplification that could lead to misleading conclusions. Cells shaded in yellow are meant for user input. All other values are calculated automatically based on those inputs.
For convenience, the calculator is pre-filled with generic values derived from grower discussions and informal benchmarks. These default numbers are meant only as placeholders and to provide general reference. They are not sufficiently accurate on their own to support financial decisions.
Users should replace all default values with operation-specific data whenever possible. As with any economic model, the quality of the output depends entirely on the quality of the inputs.
The calculator is organized into three spreadsheets (see tabs at bottom).
1. Introduction
This tab provides general instructions and contact information. No data entry is required.
2. Sections Explained
This is a reference tab that explains each section of the calculator in detail. It is intended to help users understand how different inputs affect the results and the intention of each section (small table) withing the sheet. No values should be entered here.
3. Calculation Sheet
This is the main working tab. All data entry occurs here. To prevent accidental changes that could break formulas, the sheet is protected. For most input fields, a brief explanation is provided immediately to the right of the cell. In the results section, short interpretations are often included, such as: “Decrease of 36% ($101,250/year) in hand-weeding cost with optical sprayer.” Within this tab, scenario tables are also provided. These tables are designed to illustrate how different acreages of the two crops analyzed affect each of the calculated financial indicators.
Insights from scenario testing
Even using rough approximations, several consistent patterns emerge from adjusting the calculator inputs:
Herbicide savings alone rarely justify the investment
In high-value horticultural crops, herbicide costs are often a relatively small portion of total production costs compared with labor, equipment, and the overall value of the crop. In many cases, any reduction in herbicide expenditure is largely offset by increased tractor hours resulting from slower operating speeds and narrower effective spray widths typical of optical sprayers.
Labor savings can be decisive
When the technology results in meaningful reductions in hand-weeding, the financial impact can be substantial. This is especially true in crops such as onions, where hand-weeding is both costly and difficult to source reliably. In these situations, labour savings alone can drive a favorable ROI.
Yield protection may outweigh cost savings
Several growers report stand losses and weakening associated with herbicide phytotoxicity as a major production risk. By limiting spray exposure to crop plants, optical sprayers can significantly reduce or even eliminate this issue. In high-value systems, relatively small yield gains resulting from improved crop safety can translate into revenue increases large enough to justify the technology, even if other savings are modest.
Scale matters
When evaluating advanced sprayer technologies, scale becomes a decisive factor. The high capital investment and ongoing service fees may be difficult to justify for small, and in some cases, even medium-sized operations.
What about herbicide resistance?
The long-term implications of optical sprayers for herbicide resistance management are still uncertain. Recent research from the University of Arkansas has raised concerns in field crop systems, suggesting that poorly optimized optical spraying can result in short term gains, but these can be outweighed over time by higher weed escape rates compared with broadcast applications. If these escapes are allowed to grow and set seed, rapid seedbank replenishment and accelerated resistance development may occur.
This highlights an important limitation of short-term ROI calculations. A single-year economic benefit may look attractive, but if the system allows even a small number of weeds to consistently escape and reproduce, the long-term consequences can be severe.
On the other hand, optical sprayers may eventually enable new resistance-management strategies. It is possible that new active ingredients, higher labelled rates, or novel use patterns could be registered specifically for targeted spraying in horticultural crops that would not be feasible with broadcast applications. Such developments could significantly improve resistance management tools. As always, it is essential to remember that the label is the law: only registered products and rates may be used, regardless of perceived crop safety.
ROI implications beyond herbicide spraying
Optical sprayers can deliver value beyond herbicide applications, even though weed control is their primary use. These additional uses may improve overall ROI. However, because their economic impact is still difficult to quantify, they have not been included in the calculator.
Depending on the model, additional value-generating capabilities can include:
- Creation of weed maps: Some systems can generate weed maps automatically while spraying, at no additional operational cost. These maps can support future management decisions.
- Application of fertilizers and other pesticides: Although optimized for herbicides, optical sprayers may also be used to apply other inputs, such as fertilizers or non-herbicide pesticides.
- Crop thinning: Certain manufacturers have developed algorithms for automated crop thinning, particularly in crops like lettuce.
Conclusion
Even using approximate inputs, it is clear why optical sprayer adoption is expanding rapidly in Canada.
- For medium to large-scale operations, the ROI can be highly attractive, and the range of potential benefits continues to grow.
- As the technology matures, more equipment options are emerging to serve a wider diversity of crops and farm sizes.
- Manufacturers are introducing wider and more flexible platforms, and Ontario-based companies are actively developing alternative machines and service-based business models that may better suit smaller operations.
It is difficult to argue that optical spraying is a passing trend. While it’s not a universal solution and must be implemented carefully, the technology is clearly here to stay. It will reshape weed management and production economics over the long term.