Phosphorus Acid
Type: Fungicide
Mode of Action: Stimulation of plant natural defenses / Inhibition of fungal cellular processes
Common Product Names: Phostrol
What is it?
Phosphorus acid (H₃PO₃) is a systemic fungicide, meaning it is absorbed by the plant and transported throughout its tissues. This systemic property allows it to protect new growth that emerges after application. It is commonly used to manage diseases such as downy mildew, phytophthora, and pythium, which can severely impact crops like grapes, avocados, and vegetables.
How does it work?
Once applied, phosphorus acid is absorbed by the plant and moves upward (acropetally) through the xylem. It works by Inhibiting pathogen development. Phosphorus acid disrupts the pathogen’s cellular metabolism, preventing its growth and reproduction. It also stimulates plant defenses. It triggers the plant’s immune response, enhancing its ability to fend off infections.
