Article by Jeannine Masse
Crop Sales Specialist
AGRIS Co-operative - LEAMINGTON
Wheat is a crop that thrives on good management, and timely fungicide applications are one of the most powerful tools you have to protect both yield and grain quality. Understanding the three key stages for fungicide application — T1, T2, and T3 — can help ensure your crop is protected from early leaf disease through to grain fill.
T1: Stem Elongation Stage
Target: Early leaf disease prevention
Timing: Before flag leaf emergence
This early application protects the plant from diseases like Stripe Rust, Common Leaf Rust, and Powdery Mildew. These pathogens can establish early and reduce photosynthesis if not controlled, setting your crop back before it has a chance to reach its potential.
T2: Flag Leaf Stage
Target: Protecting the flag leaf
Timing: After the flag leaf is fully emerged
The flag leaf contributes up to 70% of the plant’s total yield. Protecting it is critical. T2 fungicides target the same leaf diseases as T1, but at a stage when the plant is putting its energy into grain development. Skipping this stage can lead to serious losses in both yield and grain quality.
T3: Heading Stage
Target: Fusarium Head Blight prevention
Timing: At 50% flowering on the main stem
Fungicide is essential for protecting the wheat head during grain fill. Fusarium Head Blight (FHB) can cause shriveled, discolored kernels and lead to elevated DON (vomitoxin) levels — affecting both grade and marketability. This application is different than T1 and T2, targeting the spike instead of the leaf.
Disease ID at a Glance
- Stripe Rust: Orange stripes along leaf veins
- Common Leaf Rust: Scattered orange-brown pustules
- Powdery Mildew: White powdery mold with dark specks
- Fusarium Head Blight: Bleached heads, shriveled kernels, pink fungal growth
Application Tips: Get the Most from Your Fungicide
Coverage is critical. Use high water volumes and fine droplets to ensure even application across plant surfaces. Better coverage means better protection.
Also, be mindful of application windows. Applying the right fungicide at the wrong time can lead to reduced efficacy — or worse, negatively impact yield or grain quality. Fungicide is a preventive tool, not a cure, so timing it correctly is everything.
Plan Ahead — The Crop Moves Fast
With flag leaf now visible in many fields and heading just around the corner, it’s the ideal time to consider a T2 or T3 application. Every pass in the field is an investment in yield.
👉 Talk to your local AGRIS Crop Sales Specialist today to determine the right fungicide strategy for your farm — and make every acre count.