Crop Tech

October 24, 2015 02:34 AM
Crop Tech

By Sonja Begemann and Chris Bennett

Tar Spot: What You Need to Know About this New Corn Disease

Tar spot shows up as yellow and brown lesions on leaves and husks with raised round black structures. Although the black structures can be significant, little is known about how much they affect yield.

The discovery of tar spot, a new disease affecting corn in the Midwest, has many farmers worried about the threat of lower yields, rejected corn and higher management costs. So far, the disease has been confirmed in three counties in Indiana and three in Illinois, says Kiersten Wise, Purdue University Extension field crop disease specialist and associate professor of plant pathology. Wise helped discover tar spot in Indiana.

Weather was likely a factor in tar spot’s arrival in the Corn Belt. The disease is usually found in humid, cool conditions, typically in the highlands of Mexico, Wise notes. 

“While we don’t know how the fungus arrived, inoculum might have been transported by a tropical storm, and we happened to have the cool, humid conditions that favor disease development in our area,” she adds.

There are two fungi associated with tar spot, but only one, Phyllachora maydis, has been identified to date in the U.S. That’s good news because tar spot caused by Phyllachora maydis is not known to cause significant yield and economic damage. However, when coupled with another fungus, Monographella maydis, severe yield loss can occur.

While it’s yet to be determined if tar spot affected yields this past growing season, it’s comforting to know U.S. farmers have two advantages against this disease, Wise says. As previously mentioned, only the less harmful fungus associated with tar spot has been identified in the Midwest. Second, this fungus doesn’t survive well on dead plant material, and since it’s used to warmer climates, its chances of survival might be slimmer in a typical long, cold Midwest winter. 

“It’s a new disease but nothing to panic about. However, we need to learn what we can and determine what, if any, potential impact the disease might have in the U.S. in the future,” Wise says. “Knowing what you have is the best defense.”

Penxcel Technology Thinks Outside the Ag Box

Fertilizer and human skin are sharing the benefits of a unique technology. Eco Agro, an additive chemical company providing enhancers to fertilizers, seeks solutions outside the box—a practice that led to Penxcel technology. 

A component of Penxcel technology is used in joint and arthritis medicine, is popular in veterinary medicine and can be rubbed on human skin to deliver a drug into the body. The same delivery principle is used with fertilizer granules. 

“Through the delivery of additives, Penxcel is used in a line of products improving the efficiency of nitrogen and phosphate fertilizers,” says David McKnight, chief technology officer, Eco Agro. Products include N Yield nitrogen stabilizer, N-Bound nitrogen stabilizer and Phos Gain enhancer.

N Yield prevents the natural 30% loss of urea’s value when applied to the soil. N-Bound, a nitrification inhibitor, prevents nitrates from leaching out of the soil, an area of growing environmental interest. N-Bound also provides a longer release of nitrogen over time. Phos Gain, an enhancer not yet on the market, helps release phosphate for plant absorption.

Formulation research beyond fertilizer is underway for all facets of agriculture, excluding herbicides and pesticides, McKnight says. 

For additional details, visit

Novozymes Creates Ethanol Enzyme

Novozymes is using Liquozyme LpH to increase ethanol efficiency. The alpha-amylase enzyme thins corn mash by breaking starch into shorter dextrin chains, even at low pH. This creates a more fluid mash and increases overall efficiency for ethanol production at a low pH.

Novozymes claims plant trials show improved liquefaction and viscosity levels, which enables customers to reduce use of chemicals to adjust pH levels. This can save cost and make a safer work environment. 

For more information, visit 

Back to news


Spell Check

No comments have been posted to this News Article

Corn College TV Education Series


Get nearly 8 hours of educational video with Farm Journal's top agronomists. Produced in the field and neatly organized by topic, from spring prep to post-harvest. Order now!


Market Data provided by
Brought to you by Beyer