Systemic Turf Fungicides

Systemic, or penetrant, turf fungicides are absorbed into treated plant tissue. Movement varies by active ingredient: some move upward in the xylem, some move locally across a leaf, and phosphonates can move more broadly. Systemic does not mean that every part of an untreated plant will receive a full dose.

Choose the Right Product

Match the product to the pathogen and infection site. Foliar diseases may need the spray retained on leaves, while crown and root diseases may require immediate irrigation. Compare the FRAC group and disease spectrum rather than relying on the word systemic alone.

Build a Better Program

Apply early, use enough carrier volume for the target, and protect new growth according to the label interval. Rotate FRAC groups and use mixtures only when each partner is effective against the target disease.

What University Guidance Says

Penn State's 2025 phosphonate review explains that mobility differs among systemic groups and that phosphonates are strongest preventively against Pythium and other oomycetes. The same article cautions that phosphite fertilizer terminology is not interchangeable with a registered fungicide claim.

University sources: Penn State Extension: Understanding Phosphonate Products.

Always verify the disease, turf species, use site, rate, interval, and application directions on the current product label.