For those few fungicides where it may be a concern, the hydrolysis acts on only the small soluble fraction of fungicide. The bottom line is that alkaline hydrolysis is not an issue with most modern fungicides (they are listed as “stable” in Table 1). Breakdown in the spray tank often is associated with high pH (alkaline hydrolysis). Half-life in water is relevant to fungicide stability in the spray tank and may be influenced by water quality. Half-life in soil and water are not related, and they impact different segments of a product’s journey from the package to the turf surface. Table 1 includes published half-life estimates for selected fungicides in aerobic soil and water.
It is a measure of its persistence in the environment.
Half-life is the time required for a substance to be broken down into half the original amount. There’s been a fair amount of chatter lately about fungicide half-life and what it means for disease control and fungicide resistance risk.
