What Is Fosetyl-Aluminum and Why Is It Widely Used in Crop Protection?

Technical Introduction

Fosetyl-Aluminum (often abbreviated as Fosetyl-Al or Aliette®) is a systemic fungicide belonging to the phosphonate (phosphite) chemical group. It has a unique dual mode of action:

1. Direct antifungal activity – inhibits the growth of Oomycetes such as Phytophthora, Pythium, and Plasmopara.

2. Indirect plant defense stimulation – enhances the plant’s own natural defense mechanisms (induced resistance), strengthening cell walls and triggering phytoalexin production.

This dual effect makes Fosetyl-Aluminum highly valuable in long-term crop protection and resistance management programs.

Applications

• Fruit Crops (Citrus, Apples, Grapes, Stone Fruits):

  • Controls Phytophthora root rot, crown rot, and gummosis in citrus.

  • Protects grapes from downy mildew (Plasmopara viticola).

• Vegetables:

  • Used in lettuce, cucumbers, onions, and peppers for protection against downy mildews.

• Ornamentals & Forestry:

  • Effective against Phytophthora and Pythium root diseases in nurseries, greenhouses, and forest trees.

• Tropical Crops (Pineapple, Cocoa, Avocado):

  • Provides protection against Phytophthora heart rot and black pod disease.

• Turf & Lawns:

  • Widely used to control Pythium blight and root rot on golf courses and sports fields.

Advantages

• Systemic Protection: Moves both upward (xylem) and downward (phloem) in the plant, offering full systemic activity.

• Unique Dual Action: Combines direct antifungal activity with plant defense stimulation.

• Highly Specific to Oomycetes: Very effective against Phytophthora, Pythium, and Plasmopara.

• Low Resistance Risk: Because of its dual mechanism, resistance development is slower compared to single-site fungicides.

• Flexible Application: Can be applied as foliar sprays, soil drenches, trunk injections, or seed treatments.

• Crop Safety: Well tolerated by a wide range of crops.

Specifications (Typical Parameters)

FAQ

Q1: What is Fosetyl-Aluminum mainly used for?
A: It is widely used to control Oomycete pathogens such as Phytophthora, Pythium, and Plasmopara in fruits, vegetables, ornamentals, and turf.

Q2: Is Fosetyl-Aluminum systemic?
A: Yes, it is fully systemic, moving both upward and downward in the plant, which is rare among fungicides.

Q3: Does Fosetyl-Aluminum prevent or cure diseases?
A: It provides preventive protection, some curative activity, and long-term defense by stimulating plant resistance.

Q4: Can it be used in mixtures with other fungicides?
A: Yes, it is often mixed with contact fungicides like mancozeb, copper, or chlorothalonil for broader protection.

Q5: What crops benefit most from Fosetyl-Aluminum?
A: Citrus, grapes, apples, avocados, cocoa, pineapple, lettuce, cucurbits, onions, and turf grasses.

Q6: Is resistance to Fosetyl-Aluminum a concern?
A: Resistance risk is low due to its dual mode of action, but best practice is to rotate with other fungicide groups.