The Importance of Early Crop Protection
24 March 2022, Australia: Applying an in-furrow fungicide at seeding is a good time management tool for later in the season and an early application could offer protection for up to 4-6 weeks in cereals buying you time to get all those other important “jobs” done.
Trial results from across WA have shown that a fungicide treatment at seeding could delay the onset of disease and can reduce the impact of diseases on crop yield significantly.
Early fungicides could be applied as a seed dressing, fertiliser coating or in-furrow mixed with liquid fertilisers depending on your farming operations.
Dual applications (Banding and in-furrow), seems to be the most effective way of managing disease with the most consistent yield responses.
In barley, a flutriafol 500g/L application could increase the protection of leaf rust significantly and in stubble infected barley applying an in-furrow fungicide application you can suppress both net and spot- type net blotch.
Net blotches are unfortunately fast becoming more common and can cause more than 30% yield loss in susceptible varieties when grown on previous season infected stubble.
Field trials done by the Department of Primary Industries and Regional Development Agriculture and Food showed that banding flutriafol at sowing time, combined with a fungicidal seed treatment resulted in a significant increase in control of Rhizoctonia.
Rhizoctonia develops rapidly after opening rain and in a worst-case scenario cause up to 25% in yield loss.
When root growth is restricted (poor nutrition or limited moisture) and it’s combined with cool soil temperature, the root damage is at its worst and bare patches will appear in the paddock.
Crop rotations also play an important role in managing the spread of Rhizoctonia.
Cereal on cereal rotations is the worst for spreading the fungi, and as this can’t always be avoided, managing the spread further is important.
Seed and in-furrow fungicides
Seed dressings and in-furrow fungicides can contain one or more active ingredients and when it comes to choosing the correct fungicide for your farming operations, reassess your disease risk by looking at the seasonal forecast, crop disease forecast for your local area and asses the rotation to understand what disease will be pressuring in that particular paddock.
Seed and in-furrow fungicides offers protection against the following diseases:
- Wheat Stripe and leaf rust
- Yellow spot, Septoria tritici blotch
- Barley scald
- Powdery mildew
- Barley net blotch
Triadimefon, flutriafol, azoxystrobin with metalaxyl-M are some registered products that could protect against Stripe Rust in wheat and flutriafol or triadimenol seed dressing could suppress stripe rust in younger crops.
Azoxystrobin/metalaxyl-M actives have proven to suppress early yellow spot in wheat.
To control powdery mildew in barley, early protection is necessary with a registered seed dressing or in-furrow fungicides.
Some registered seed dressings are Systiva (Fluxapyroxad) or Uniform (azoxystrobin+metalaxyl-M) can be used as an in-furrow protection.
Uniform also has a registration for Rhizoctonia and Pythium control in Wheat and Barley, 2 diseases which have been tough to manage in certain areas.
Silly Seed Syndrome
Caution and planning is critical when applying Fungicide seed dressings in order to reduce the risk of ‘silly seed syndrome’, where the coleoptile will shoot under the surface, but due to the shortening of the coleoptile due to the fungicide, the shoot may not emerge from beneath the soil surface. Correct placement of the fungicide and seed is paramount to reduce the risk of ‘silly seed’.
Depending on your area, disease resistant varieties are becoming more and more popular to reduce the risk of resistance. Selecting a variety with good disease resistance and rotating crops could reduce the risk of resistance significantly and lower the usage of fungicide in crops.