Main authors: Luke Farrow, Mark Browne, Erica Chisholm, Ida Hamill, Patrick Meier, Paul Armitage, Rachel Cassidy, Rikke Krogshave Laursen, Peter Schipper, Gerard Velthof and Donnacha Doody
Editor: Jane Brandt
Source document: »Farrow, L. et al. (2021) Development of the SprayDay mobile app - assisting best practice amongst infrequent pesticide users. FAIRWAY Project Deliverable 5.5, 47 pp


Contents table
1. Front page
2. Weather
3. Calibration and dilution calculations
4. Pesticide labels
5. Best practice tips
[Note: The Appendix referred to below is included in the »full report]  

The app consists of a front page as well as four themed areas and all are introduced below.

1. Front page

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Figure 5

Figure 5 illustrates the first screen that the user sees when the app opens and it offers them information on the current weather conditions and access to the four sections of the app. Along the bottom there is a navigation strip that also allows the user to move between sections. This strip is present in all screens and so it is not necessary for the user to return to the main screen in order to navigate between sections.

As a current weather forecast is vital information when planning pesticide applications the app attempts to contact AFBI, where the current weather forecast is held, when the app is opened. When contact is made, the latest forecast data is downloaded and displayed. Where a connection cannot be made data from the last forecast received is displayed. The user is able to check the age of the forecast as the last line in this section shows the date and time when the forecast was last updated. If necessary, the user may use the update button located to the right of the temperature to download the latest forecast.

2. Weather

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Figure 6

This section of the app provides the user with a more detailed description of weather conditions for spraying over the next five days at their location (Figure 6). The UK Meteorological Office previously developed the “Good Day to Spray” protocol that categorises the suitability of each hour for spraying (returning the result “Suitable” or “Unsuitable”), based on the parameters outlined in Error! Reference source not found.. When opened the app requests the GPS location of the mobile phone (where the user has permitted this information to be shared) and shares this information with the AFBI servers where weather data is held. The GPS location is used to identify the most spatially appropriate weather forecast and this information is returned to the app. The GPS data is then deleted. The weather data held by AFBI is updated every six hours.

The output of the protocol is presented to the user for each hour between 6am and 10pm for each of the next five days and, again there is a timestamp at the top right of the screen showing when the data was last updated. If the app has been unable to contact the AFBI servers for more than 6 hours a message appears informing the user of this, and suggesting they should update the weather data. If no connection is made for more than 48 hours this section of the app will cease to function until such time as new data is received.

In the prototype app it is not possible to provide information on today’s spray periods. It is recognised that this is a weakness and the steps required to resolve this are known, however addressing this required more time than was available in the current project. This will be considered in future development of the app.

Table 1: Parameters used by the “Good Day to Spray” protocol to determine if weather conditions are suitable for spraying activities.

Parameter Conditions
Time Values are returned for the period between 0600 and 2200
Precipitation No precipitation should be expected in the previous or current hour
Wind speed Wind speeds should be less than 10 mph at 10m above ground level
Temperature Average temperature should be greater than 1°C in the current hour Temperatures should exceed 7°C at some point during the day of interest

3. Calibration and dilution calculations

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Figure 7
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Figure 8

The calibration of a sprayer and dilution of pesticides both require mathematical calculations to be performed. If, as is often the case on grassland-dominated farms, these steps are performed infrequently and so can be a major source of error and expense for the user.

The app records details of each sprayer and reminds the user when it is more than one year since calibration was last undertaken (Figure 7). Sprayer types supported are boom sprayer (tractor-mounted and quad-mounted), knapsack and weed wiper.

The app uses the workflow outlined in the CAFRE-presented training courses (validated by City and Guilds) that all professional pesticide users in the UK are required to attend (See Appendix B in the »full report for details of the training courses and links). The app asks simple questions and performs the calculations for the user (Figure 8). Details of the calculations undertaken in this section can be found in Appendix C in the »full report.

No information from this section of the app is shared with third parties

4. Pesticide labels

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Figure 9

An area where app users keep images of any aspect of the pesticide containers or sprayer(s) for future reference. (No information is shared with third parties). The capacity of the app to store photographs is limited by the same hardware constraints as apply to other photograph storage on the device. The user is able to “View”, “Edit” or “Delete” any entry (Figure 5a) and each record includes a section for the user to records comments (Figure 9)

5. Best practice tips

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Figure 10

This is intended to act as a quick reference section that either provides a brief answer to a user’s questions around pesticide usage and storage best practice or guides them to more extensive resources on the internet. The focus of the text is on encouraging best practice disposal of pesticides (diluted as well as undiluted), bottles, foil seals, contaminated Personal Protective Equipment and materials used to deal with a spill (Figure 10).

When this section of the app is opened, the app contacts the server at AFBI and declares the issue number of the text currently held. The server compares this value with the document number of the latest version of the document. When the number is the same, no further action is taken, but where the numbers are different the new version of the text is downloaded to the app. This ensures that links and content remain current and accurate. If the app is unable to contact the AFBI server, a message will appear warning the user that the document may be out of date.


Note: For full references to papers quoted in this article see »References

Download the full report for the Appendices


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