[Q&A] Do You Need to Add a Surfactant When Spraying Glufosinate Ammonium?

Farmers often ask: Is a surfactant necessary when spraying Glufosinate Ammonium? This article explains the benefits, when to use it, how much to add, and important safety tips to maximize herbicide performance.

Table of Contents

1. What Is a Surfactant?
2. Do You Need to Add a Surfactant to Glufosinate?
3. When Should You Use a Surfactant?
4. How Much Surfactant to Add?
5. Important Tips When Using Surfactants
6. Conclusion

1. What Is a Surfactant?

A surfactant (or spray adjuvant) is an additive mixed with crop protection products to:

• Improve adhesion of herbicide to weed leaves
• Help retain the solution longer on surfaces – minimizing wash-off
• Enhance even coverage and penetration, especially on waxy, slick, or narrow leaves

2. Do You Need to Add a Surfactant to Glufosinate?

The answer is: Yes – in certain cases.

Glufosinate Ammonium is a contact herbicide, meaning it only works on the parts of the weed that are directly sprayed.

👉 If the herbicide doesn’t stick well — especially on narrow-leaf, waxy, or slippery weeds, or in humid conditions — the effectiveness can drop significantly.

👉 Adding a surfactant improves sticking and retention, allowing the herbicide to remain in contact long enough to take full effect.

3. When Should You Use a Surfactant?

Scenario	Should You Add a Surfactant?
🌿 Narrow-leaf, waxy, or slippery weeds	✅ Strongly recommended
🌧 Spraying in humid or dewy weather	✅ Recommended
💦 Areas with strong overhead irrigation	✅ Recommended
☀️ Dry weather, broadleaf young weeds	❌ Usually not necessary
🚜 Using low-pressure sprayers	✅ Helps improve coverage

4. How Much Surfactant to Add?

• Typical rate: 2–5 ml of surfactant per 16 liters of water
• Adjust based on product label instructions

📌 Caution: Overuse can cause minor leaf burn if the solution sticks too aggressively to crop foliage.

5. Important Tips When Using Surfactants

✅ Use surfactants specifically made for herbicides – avoid unverified foaming agents or mineral oils
✅ Always add surfactant last – after herbicide is fully mixed
✅ Stir the tank thoroughly to ensure even mixing
❌ Do not use surfactant when crop seedlings have soft, low-hanging new leaves
❌ Avoid spraying if rain is expected soon – even with surfactant, allow 4–6 hours drying time

6. Conclusion

Adding a surfactant when spraying Glufosinate Ammonium can significantly improve herbicide performance – especially for waxy-leaf weeds, narrow grasses, or in humid environments.

👉 However, it’s not always required. Farmers should evaluate their specific conditions to decide whether or not to include a surfactant.