By Obiabin Onukwugha
There are reports of corn diseases in Indiana counties as a result of climate change impacts.
Most reports indicate that despite a shaky start during planting season and localized severe flooding and wind events, corn looks good so far in many areas. However, diseases and other issues, including dry weather, are now emerging, sparking fears of low yield.
Apart from food purposes, corn and soybeans grown in the state of Indiana are made into biofuels and fibre materials such as ethanol and carpet. What we grow in Indiana does not all stay in the state. Also, Indiana makes more than $4.6 billion in revenue from agricultural products exported throughout the world, producing important economic benefits for the state.
The communities in Indiana, known as the corn belt are;; Illinois, Iowa, Missouri, eastern Nebraska, and eastern Kansas, in which corn (maize) and soybeans are the dominant crops.
It is reported that the Corn Commentary field in central Indiana at the end of July revealed the value of crop scouting, even after corn pollinated and began the grain fill stage. It was observed that the corns were disease-free two weeks ago but now exhibit considerable gray leaf spot lesions on lower leaves.
In many cases, lesions were spotted on the leaf below the ear leaf but not on the ear leaf itself. However, farmer reports indicate that in bottomland fields planted earlier, grey leaf spots have advanced to the ear leaf and even to leaves above it.
Southern rust has been confirmed in many counties in eastern Nebraska. It is also confirmed in Iowa, Missouri, Kansas, Kentucky, southern Illinois, and southern Indiana. Some suspect it travelled northward with the remnants of Hurricane Beryl and is now making its appearance.
Corn growers in these areas have been encouraged to continue scouting even after a fungicide has been applied earlier. However, depending on the product and the target disease, applications are only effective for two to three weeks.
So far, southern rust has been confirmed in two southwestern Indiana counties, Knox and Dubois. Some fungicides are better at controlling southern rust than others.
Tar spot is also confirmed in a significant number of counties in Iowa, Missouri, Nebraska, eastern Kansas, southern Wisconsin and Michigan; and in scattered counties in southern Illinois, northern Kentucky, Ohio and even as far east as Pennsylvania.
In Nebraska, southern rust has been confirmed in more than a dozen counties. It is patchy at local levels in affected counties, meaning it’s easy to find across some fields but seemingly not present in other nearby fields within a handful of miles. This distribution pattern is common for southern rust early after it moves into the state.
In Minnesota, growers have asked if applying extra nitrogen is worth it in these conditions.
“We really need to see a sample to confirm whether it is common rust or southern rust. We confirm it by examining the spores under a microscope.
“So far, southern rust is confirmed in two southwestern Indiana counties, Knox and Dubois. Some fungicides are better at controlling southern rust than others. Growers can check university ratings for the effectiveness of various fungicides on specific diseases,’ explains Darcy Telenko, Purdue Extension plant pathologist in Indiana.