Agronomists and advisers (Teagasc and private): the wind call, at your height

As a crop adviser or agronomist, you make daily decisions during the spraying season. You tell each client whether to spray or hold for the day, based on local conditions. This decision is critical for effective application and to meet regulatory requirements.

Making the wrong call can have consequences. If you advise spraying during unsuitable conditions, the application might be ineffective, leading to re-application costs or crop damage. Conversely, holding back when conditions are favourable can delay essential treatments, impacting crop health and yield.

Your professional reputation and potential liability are tied to these recommendations. You need to ensure your advice is consistently sound and supported by reliable data. The instrument helps you gather the necessary information to make these calls with confidence, for each of your clients.

Your advice needs to be consistent across your client base, even when dealing with varied microclimates. The instrument helps you standardise your approach and provide clear, data-driven recommendations.

For spraying operations, the critical wind measurement is at boom height, typically around 2 metres above the ground. While forecasts often provide wind speeds at higher altitudes (10 metres and above), these do not accurately reflect the conditions at your working height.

Wind speeds at 2 metres can differ significantly from those at 10 metres. The instrument interpolates wind speeds to your specified working height, showing you the mean wind speed and gust speeds at 2 metres. This allows you to assess the actual conditions relevant to your spraying equipment.

Your spraying limit is set by the product label and Sustainable Use Directive (SUD) rules. This limit is specific to boom-height wind and often includes considerations for Delta T. You will input your specific limit into the instrument, typically in kilometres per hour.

Using interpolated data at 2 metres helps you adhere to these limits more precisely, avoiding drift and ensuring product efficacy. This precision is essential for meeting regulations and for effective crop protection strategies.

The instrument shows you the probability (P(above your limit)) by the hour. This is computed from ensemble members at various heights (10, 80, 100, and 120 metres), indicating the fraction of these members that predict wind speeds above your set limit for that hour. This is not a calibrated certainty, but a measure of how many model runs exceed your threshold.

For example, if the instrument shows 20 per cent P(above your limit), it suggests that a small proportion of the model runs exceed your threshold. In this scenario, you might advise clients to proceed with caution, monitoring conditions closely. If it shows 50 per cent, there is a significant chance of exceeding your limit, prompting you to consider delaying operations or preparing for a narrow window.

When the odds reach 80 per cent P(above your limit), it indicates a high likelihood of unsuitable conditions. At this point, you would typically advise clients to hold off on spraying for that hour. The Agreement Spine shows where weather models concur or diverge, giving you insight into the forecast's reliability.

Understanding these odds helps you make informed decisions for each client, balancing the need for timely application with the risks of adverse wind conditions. This allows you to communicate the likelihood of suitable conditions clearly to your clients, reducing their need to call you for updates.

This is an example of how you might use the instrument in a typical day during the spraying season:

6:00 AM: You check the instrument. For a client's field, the boom-height wind at 2 metres is forecast at 8 km/h, with gusts to 12 km/h. The P(above your limit) is 10 per cent for the morning, rising to 60 per cent by midday. You see the Agreement Spine shows good model consensus for the morning.

6:30 AM: You text 40 clients with a verdict. For this client, you advise them to spray early, before 11:00 AM, and then hold. You include a link to the public board for their specific field, so they can monitor conditions themselves.

10:00 AM: The instrument updates. The boom-height wind is now 10 km/h, with gusts to 15 km/h. The P(above your limit) has risen to 70 per cent for 11:00 AM. You see the Agreement Spine showing increasing model disagreement for the afternoon.

10:30 AM: You send a follow-up message to clients who were spraying, advising them to finish operations by 11:30 AM due to worsening conditions. You check the dated record page to confirm your initial advice and the conditions at that time.

2:00 PM: You review the day's records. The instrument shows the observed wind speed at 2 metres reached 18 km/h by 1:00 PM, confirming your decision to advise clients to hold. You note this for future reference and for any client queries.

Your spraying operations are governed by specific wind speed limits, which are typically found on product labels and within Sustainable Use Directive (SUD) rules. These documents specify the maximum acceptable wind speed at boom height for effective application.

When you set up the instrument, you will input your specific limit, for example, 11.8 miles per hour, or its equivalent in kilometres per hour, for boom-height wind at 2 metres. This ensures all forecasts and probabilities are assessed against your exact operational threshold, not a generic one.

This personalised setting is crucial because exceeding your limit can lead to spray drift, reduced efficacy, and potential regulatory non-adherence. The instrument defaults to a 2-metre height for agronomist and adviser users, reflecting the typical boom height for spraying equipment.

By accurately setting your limit, you ensure the instrument provides relevant and actionable data for your daily decision-making process. This helps you meet regulations and maintain best practice in your advisory role.

The instrument maintains a dated record page, showing what was forecast and observed, the limit you used, and the call you made for each day. This record is essential for your professional practice as an agronomist or adviser.

Clients, auditors, or regulatory bodies may ask for evidence of your due diligence in making spraying recommendations. This record provides a clear, verifiable log of the conditions you based your advice on. It documents your adherence to product label instructions and SUD guidelines.

Having a clear record covers your advice on the day. If a client queries a past recommendation, or if there are questions about spray efficacy, you can refer to the precise conditions and forecasts that informed your decision. This protects your professional reputation and provides a defence against potential liability claims.

Beyond meeting regulations, these records help you refine your advisory practices over time. You can review past forecasts against actual observations to better understand local microclimates and improve your future recommendations. This continuous learning is vital for providing accurate and reliable advice to your clients.

Ireland's agricultural landscape, particularly its exposure to Atlantic weather systems, means wind conditions are a constant consideration for agronomists and advisers. The spraying season, typically from March to July, often coincides with periods of variable and sometimes strong winds.

Met Éireann provides national forecasts, but local variations can be significant. The instrument provides site-specific wind data, interpolated to your boom height, which is more relevant than broader regional forecasts for spraying decisions. This helps you account for the nuances of local topography and field exposure.

Adherence to Sustainable Use Directive (SUD) guidance, as advised by bodies like Teagasc and the Department of Agriculture, Food and the Marine, is paramount. These guidelines often specify wind speed limits for pesticide application, which the instrument helps you monitor precisely.

During the storm season, generally October to March, while less relevant for active spraying, understanding wind patterns is still important for planning and assessing field access. The instrument supports your daily decision-making throughout the active growing season, helping you navigate Ireland's often challenging weather conditions.