• Enter your email address to follow this blog and receive notifications of new posts by email.

    Join 1,791 other followers

  • Southern IPM blog posts

    June 2016
    M T W T F S S
    « May   Jul »
     12345
    6789101112
    13141516171819
    20212223242526
    27282930  
  • Funded by USDA National Institute of Food and Agriculture

    The Southern Region IPM Center is located at North Carolina State University, 1730 Varsity Drive, Suite 110, Raleigh, NC 27606, and is sponsored by the United States Department of Agriculture, National Institute of Food and Agriculture.
  • Southern IPM Tweets

Southern rust and tar spot of corn are on the move

In Southeast Farm Press

by Carl Bradley, University of Kentucky Extension Plant Pathologist

Two corn diseases are already making some news this season. Southern rust and tar spot have been detected in southern states and could potentially make their way to Kentucky this season. So, keeping a lookout for these two diseases is a good idea.

Southern rust

Southern rust (caused by Puccinia polysora) made an appearance in Kentucky last summer, and turned many combines orange during harvest because of the large number of orange-colored pustules present on the leaves.

Although the fungus that causes southern rust is not able to over-winter in Kentucky, it has already been found in corn fields in Texas, Louisiana, and Georgia this year. This pathogen will move north during the season, but timing is everything. If the disease is found in Kentucky corn fields prior to the milk stage (R3 growth stage), then yield losses may occur.

Wet spring weather did delay corn planting in some areas this year, so the table could be set for this disease to be a problem, especially in late-planted corn.

Tracking the whereabouts of southern rust in the U.S. will help determine when it may move into Kentucky, and this will continue to be a topic addressed in Kentucky Pest News— which can be found here — this season. Many fungicides are able to effectively protect against infection by the southern rust pathogen. Extension plant pathologists from corn-growing states have put together a fungicide efficacy table for corn (Fungicide Efficacy for Control of Corn Diseases, BP-160-W), which is published by Purdue

Tar spot

Tar spot (caused by Phyllachora maydis) was found in the U.S. for the first time late in the 2015 growing season in the northern portions of the neighboring states, Illinois and Indiana. Although this disease appeared too late in the growing season to cause yield losses, it was observed across several counties in both of those states.

On June 10, 2016, tar spot was detected on corn growing in Palm County, Fla. Although little is known about the ability of this disease to cause losses to corn grown in the U.S., it is important to be on the lookout for the disease.

Since this disease has never been reported in Kentucky, it is critically important to work with your local county Extension agent to submit any suspect samples to the University of Kentucky Plant Disease Diagnostic Lab.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: