Phosphonate fungicides have very good efficacy for Pythium disorders and other health conditions caused by oomycetes when applied preventatively; but are considered to have poor efficacy when used write-up-infection (soon after condition indicators and indications are obvious.) (causal agent of lettuce downy mildew) treated frequently with phosphonate fungicides and fertilizers.three https://andersonbrixm.dailyblogzz.com/34346519/the-definitive-guide-to-role-of-map-in-nutrient-cycling