Devolopement and Validation
Today, one of the biggest problems for turf maintenance is the presence of certain diseases. Two of the most prominent ones are Snow Mold for the cold season and Dollarspot for the warm season. Furthermore, previous research has shown that by using disease models instead of a calender based approach, can reduce the pesticide application by 30%.
To better understand the dynamics of these diseases, and to proactively battle these diseases, Lumbricus has developed one of the best disease models for Snow Mold and Dollarspot that exist today.
Based on a data set containing more than 1300 measurements from over 6 years of consulting, a logistic model was developed to predict the disease activity based on regular meteorological data.
Because the validation of a model is as important as the model itself, a thorough validation was performed using a cross-validation and a 2 year practical validation.
The cross-validation showed the following accuracy:
- Dollarspot 76%
- Snow Mold 77%
The goal of the model is not just to tell golf courses that they have disease, they can see that themselves. For when you see the disease, you are already too late. Therefore, we are able to make a prediction 7 days into the future which can help the planning of preventive action.
The model works using 3 phases of disease development:
- Phase 1: No disease (0-40% for Dollarspot for example)
- Phase 2: Disease is present and developing (40-90% for Dollarspot for example)
- Phase 3: Abundance of disease, heavy damage on the grass (above 90% for Dollarspot for example)
These Phases correspond to the methods that can be used to reduce the damage that these diseases do to the Grass.
- Phase 1: Prevention i.e. water balance, nutrient balance and thatch reduction
- Phase 2: Curative without chemicals i.e. water balance, nutrient balance, thatch reduction and iron sulphate (24 kg/ha once every 2 weeks)
- Phase 3: Curative with chemicals.
Impact of the Model
The year 2020 was used for a validation experiment looking at the application at 11 different golf courses. From these courses, 2 did not use any pesticides for Dollarspot and 6 reduced the application by 50%.
From the data that was gathered during this period, even the courses that had to use pesticides were able to show that they did so in the most sustainable way possible. For when pesticides are applied in the correct way, using the correct amounts and under the correct conditions, there is no damage to the environment whatsoever – as has been shown in scientific research more than once.