Fungicide Properties

The current weather conditions have raised questions on the amount of irrigation to apply to wash in fungicides when soils are already at elevated moisture content. The physical and chemical properties of a fungicide influence its behavior in soil.

There are properties that can be used to help describe availability, mobility and persistence in soil, these are water solubility, soil binding and half-life. The solubility and soil binding will determine the amount of the fungicide that will be available to fight disease, whereas the half-life relates to the persistence of the fungicide in the environment.

Water solubility is a measure of how much of the active ingredient will dissolve in water. The more chemical that will dissolve in the water, the more likely that it will move through the soil.

Soil binding (Koc) is a measure of how tightly a chemical adheres to soil and organic matter. The higher the value the more tightly it will be bound.

Persistence is measured as the half-life which is the length of time it takes for 50% of the active ingredient to breakdown.

To move a fungicide like Banol^®(propamocarb) which has high solubility and is slightly mobile we may not need as much irrigation as with an active ingredient that has less solubility and is non-mobile. This will especially be the case if high soil moisture levels are already present. Applying too much irrigation risks moving the chemical too deep in the profile, past the root zone being targeted for protection with the fungicide.

To find out more information, reach out to our team.

Always read the label before use.