Causes of brown, scorched leaves in wheat
click image to zoomErick DeWolf, K-State Research and ExtensionBacterial leaf blight on wheat in spring 2012, in which flag leaves are becoming brown and developing symptoms of tip dieback. There have been a number of reports of wheat fields in which flag leaves are becoming brown and developing symptoms of tip dieback. In some cases this brown discoloration is very obvious from a distance giving the field a scorched appearance.
Some growers were wondering if these symptoms might be caused by chemical injury from recent fungicide applications. While this is possible, I do not believe the evidence supports this conclusion, because the symptoms are appearing in both fungicide treated and untreated fields.
I think that these symptoms are being caused by bacterial leaf blight. This disease is not well described, but is associated with bacterial infection of the leaves following periods of warm humid weather. In my experience, the symptoms of bacterial leaf blight often are most severe along the margins of a field following intense thunderstorms that bring high winds that pick up sand and other debris from roadways. This wind-driven sand creates small wounds that allow the bacteria to enter the plants and stimulate the bacterial infections. The disease is often most intense in areas of the field that lodge during these storms simply because the canopy in those areas remains wet for extended periods of time, further favoring the disease.
click image to zoomErick DeWolf, K-State Research and ExtensionClose-up of damage from bacterial leaf blight. Obviously, losing leaf area at this point in the grain development is not a good thing; however, there are no official estimates for potential yield loss caused by bacterial leaf blight. There are no treatment options for the disease.
- Adequate rhizobia populations help protect soybean yields
- In-season imagery helps farmers grow and protect healthy crops
- Ag markets proved rather volatile Wednesday afternoon
- Farm Bill enables record USDA investments in rural water systems
- Ag markets diverged Wednesday morning
- Do soybeans need N fertilizer?
- Commentary: Blame anti-GMO groups for deaths
- Julie Borlaug says biotech is necessary in fight against hunger
- What does “sustainable” food and agriculture really mean?
- Ohio bill to require certification to apply fertilizer
- Carbon-dioxide hurts nitrogen assimilation by plants
- FCC aims to offer high-speed internet to rural America