Home Garden

Treatments for Take-All Root Rot on St. Augustine Grass

Take-all root rot is a fungal disease of St. Augustinegrass caused by Gaeumannomyces graminis var. graminis. All varieties of St. Augustinegrass are susceptible to the disorder. Grass that is excessively fertilized with high nitrogen fertilizers or lime is more prone to the infection.
  1. Identification

    • Fungicidal control options for take-all root rot include the use of azoxystrobin, propiconazole and triadimefon. These chemicals are sold under a variety of different tradenames.

    Function

    • Use azoxystrobin twice in a month during spring or fall. Apply propiconazole twice to affected grass during April and May and again in September and October. Triadimefon is a preventative control option. Spray two to four weeks prior to appearance of symptoms and repeat after three to four weeks. Irrigate lawn well after application.

    Cultural Management

    • Use acidifying fertilizers like ammonium sulfate or slow release urea. Lower pH in the soil helps to control the growth of the causal pathogen. This is a biological control method of take-all root rot. Avoid the use of high nitrogen fertilizers.