Late blight can be treated more effectively with air assistance
When controlling late blight, timely and preventive treatment is crucial to protect the leaves before infestation develops. Effective spraying is therefore about getting the crop protection evenly distributed on the leaves throughout the crop so that each treatment is optimally utilized. Air assistance can improve leaf coverage, even at lower water volumes, because the airflow causes the leaves to move during spraying, so that leaves that are otherwise covered by other leaves are also hit by the spray. With conventional spraying, leaves that are covered during treatment can later be exposed when the crop moves in the wind, leaving them unprotected. In the National Trials 2025, air spraying at 50 l/ha is compared with hydraulic spraying at 250 l/ha, where there is a clear difference in the development of mold.
Development of late blight in 2025
50% dose
100% dose
Important: The experiment documents a statistically significant reduction in mold infestation with air spraying – and shows that air assistance provides a more effective treatment in potatoes.
The trials show that air-assist consistently reduces the development of late blight compared to conventional spraying. At full dose, only 2% mold was seen with air-assisted spraying compared to 6% with hydraulic spraying, corresponding to approximately 65% lower residual infestation, and the same trend is seen at reduced dose. The results prove that air-assist provides more effect per liter of spray liquid and thus a stronger and more robust protection throughout the season.
| Spraying technique | Dosage | Leaf mold, % | Starch, % | hkg tubers | hkg starch | DKK/ha |
|---|---|---|---|---|---|---|
| 1. Untreated | 97 | 20,6 | 453 | -42 | -21.944 | |
| 2. Hydraulic sprayer | 100% | 6 | 22,7 | 146 | 136 | 70.512 |
| 3. Hydraulic sprayer | 50% | 62 | 22,0 | 113 | -11 | -5.720 |
| 4. Air Sprayer | 100% | 2 | 23,1 | 152 | 4 | 2.184 |
| 5. Air Sprayer | 50% | 40 | 22,5 | 124 | -6 | -2.964 |
Important: The report also mentions a trend toward higher dividends.
Conclusion: The trial shows that better mold control can also be seen in the harvest yield. At full dosage, 152 hkg of tubers per hectare were harvested with an air sprayer compared to 146 hkg with a conventional sprayer, with a slightly higher starch content. This corresponds to an additional yield of approximately 4 hkg per hectare, which in the trial yields around DKK 2,000 extra per hectare (≈ 270 € per hectare). In short: better coverage means that a larger proportion of your treatments end up as more yield and better economics on the bottom line.
Development of late blight in 2022
50% dose
100% dose
Conclusion (2022): Both trials show the same picture: air assistance consistently results in lower mold than conventional hydraulic spraying – both at 50% dose and 100% dose. It is particularly worth noting that a 50% dose with air can in practice be lower than a 100% dose with conventional technology. In other words: you get more effect per treatment, stronger protection, and a setup that can help you achieve your goal with less input.
| Spraying technique | hkg tubers per ha | hkg starch per ha |
|---|---|---|
| Hydraulic sprayer 100% | 592,5 | 123,2 |
| Hydraulic sprayer 50% | -45,8 | -10,4 |
| Air Sprayer 100% | 3,3 | 0,7 |
| Air Sprayer 50% | -23,4 | -1,5 |
Conclusion: When you combine air assistance with a more targeted treatment, you can achieve an effect in practice that is close to what you would normally expect from a 100% dose with conventional spraying – even at a reduced dose. This is exactly the kind of robustness that adds value in the field: more "bite" per liter, more reliable coverage, and the ability to maintain the level when you want to optimize consumption, logistics, and capacity.
More impact from crop protection
More value per hectare
More profit per hectare
What does this mean in practice?
By switching to aerial spraying, you can reduce environmental impact, get more out of crop protection and increase yields per hectare. Lower water volume also means higher capacity and fewer fillings, contributing to a more efficient operation and a better bottom line economy.