Tuesday, August 6, 2013

Quick Test For Goss's Wilt

Keith called me to tell me about his new quick test for Goss's Wilt.  "Pull the ear leaf off with the ear. Instead of the normally white tissue, look for tannish, discolored tissue.  If the disease has advanced, it will stink becayse if the amalayse sugars fermenting at the base of the ear.  Many fields have double ears again this year and if the disease is advanced, the second ear will be similar to the first ear as the plant as accumulated too many sugars it cannot use.

You can verify with a quick test kit and then have that verified at a University Plant Pathology Lab like Nebraska's or Michigan State's labs.  90% of these samples have tested positive for Goss's or similar wilts in corn this year.

"Goss’s wilt of corn often is most severe after fields are exposed to high winds and/or hail damage, because the causal bacterium, Clavibacter michiganensis subsp. nebraskensis, readily infects corn leaves through wounds.  With the recent storm activity across the state, growers should be on the lookout for the appearance of Goss’s wilt symptoms.  Goss’s wilt lesions on the leaves generally have wavy margins with a water-soaked appearance on the edges of the lesions.  Dark spots, known as “freckles”, almost always can be found within the lesions.  The affected areas of the leaves will have a shiny appearance when observed in the sunlight, and bacterial exudates may be on the leaves that resemble drops of maple syrup"

"The causal agent is Clavibacter michiganensis subsp. nebraskensis and is one of only several plant diseases caused by a Gram positive bacterium. The pathogen can cause two major types of symptoms, a systemic wilt and leaf blight. The leaf blight phase of the disease is the most common and can cause the development of lesions with wavy margins similar to some other diseases. Two characteristics can be used to distinguish it from other diseases. The first identifiable characteristic is the development of dark green to black discontinuous water-soaked spots, sometimes called ‘freckles’ because of their appearance (photo), near the edges of expanding lesions. The bacteria can also create an exudate or ‘ooze’ on the surfaces of the leaf which is the second identifiable characteristic. When dried the exudate may glisten and appear shiny on the leaf surface similar to varnish (photo). The disease can also have a systemic wilt phase in which the bacteria infect the vascular system and move within the plant. Infection may cause discoloration of the water-conducting elements (photo) and eventually a slimy stalk rot that can lead to wilting and plant death (photo).

Watch that word clavibacter.  I've read and heard it too many times in gmo vs. non gmo discussions.

If we don't figure out how to combat the potential massive problems in crop production, we will have less to ship to our buyers.  Who do you sell to?  One of my buyers is CGB, one company I am not afraid to DP to.  Their financial statement is probably the best in the business.  I didn't know whether you get their newsletter or not but many of you farm near the locations they buy grain from.

Walk your fields and tell me what you find.  I haven't heard from many of you.  I think when the price dropped $2 everyone said the heck with their corn fields.



  1. Mr. Winkle, I just want to say that I really enjoy reading your blog and have gained a lot of knowledge from it and your posts on agtalk. I am currently a student at OSU ATI majoring in crop management and aspire to someday know half of what you know in crop production.

    Thanks for taking time to educate the younger generation,

  2. Wow, Jonathan, that is what keeps me thinking and typing!

    OSU ATI was very good for my oldest son Matt and many of his friends and my former students. Matt is a better ag teacher than his dad ever was at Fayetteville High School. I can't believe he started his 13th year of teaching!

    Ed Winkle