Leaf disease can show up in cereals when the plant is relatively small – in the three- or four-leaf stage. That means now is the time to get out on the field and look for lesions and symptoms of tan spot, septoria, net blotch, spot blotch or scald on the lower leaves.
The health of the flag leaf accounts for 65% of your yield; so don’t wait for disease to harass it. Take preventative measures to protect the flag leaf, and consider an early-season fungicide application.
Scout lower leaves on cereal plant for signs of disease
Fungicides are not curative – they’re preventative.Use the lower leaves of your cereal plant as an indicator of what’s to come. Diseasestarts on the lower leaves and spreads up the plant. Hot, dry conditions can slow the spread, but in general, the more disease you see on the lower leaves, the more pressure you’ll get on the flag leaf when it emerges.
If you see symptoms of disease on the lower leaves, spray an early-season fungicide to protect the flag leaf shortly after it emerges.
Assess your conditions to see if you need an early fungicide application
Fusarium head blight products are exceptionally strong leaf disease products. It makes some growers ask, “Do I spray at flag leaf timing to protect my flag leaf, or do I wait until heading and spray with my head blight products that take care of leaf disease?”
You don’t want leaf disease to take over the flag leaf while you’re waiting for heading. I know it’s a busy time of year, and you feel like you barely get to park the sprayer before you’re back out in the field making fungicide applications. But if your farm or field matches any of the following conditions, I encourage you to make two fungicide applications:
- High fusarium pressure areas
- Heavy leaf disease pressure
- Have had high DON in previous crop samples
It will be worth the time and cost to protect your crop’s yield and quality.
Make maximum coverage your spray goal
Fungicides are not systemic – they work on contact. That means it’s important to completely cover the flag leaf and get fungicide penetration into the crop canopy. Use a high water volume (min 10 gal/acre) to maximize coverage, even if it means slowing down your spraying.
The two fungicide products that I recommend are Twinline® and FOLICUR®, for their superior leaf disease control. For those concerned with fusarium, I recommend PROSARO® or Caramba®.
If you can’t decide if your crop needs an early fungicide application, or you have questions about application and what you can spray, feel free to contact me or any Cargill agronomist. We’re always happy to walk your fields and provide a second opinion. We want to help you manage crop inputs while protecting the greatest yield potential.
Always read and follow label directions. Twinline® and Caramba® are registered trademarks of BASF Corporation. FOLICUR® and PROSARO® are registered trademarks of Bayer.