May 19 Wheat Update

Damage to heads from frost/freeze is beginning to appear as white awns/florets in wheat heads.  Thankfully this damage is very minor in area wheat fields right now.

Barley yellow dwarf is also appearing in fields and is noticeable by flag leaves with a yellow/purple color.  This is a disease vectored by various aphid species.  The aphid in this photo is a corn leaf aphid and I’m seeing these in wheat as well right now in addition to lady beetles which are feeding on them.  We also observed aphids last fall and were concerned about them potentially vectoring this disease.  I would say this is my least favorite wheat disease because you can do many things correct with wheat just to have this one show up and affect yield.

Stripe rust and leaf rust are also rapidly increasing in area fields with the humidity and moisture this past week.  Fungicide options differ right now dependent upon wheat growth stage.

Wheat flowering (pollinating). Look for the small yellow anthers. The wheat head will begin pollination in the center first and then pollinate the top and bottom.  I’m also concerned about the potential for Fusarium Head Blight (scab) in our wheat right now with all the rain we’re receiving during pollination.  Only a few fungicides are labeled for wheat during flowering and the ones that are can only be applied up to 50% flowering.  These include Caramba, Prosaro, Folicur, and Proline which are slated to help prevent scab and also kill fungal diseases like rust already present on the leaves.  Read and follow all pesticide label directions. 

IMAG3504

Also seeing some loose smut in fields which again is fairly minor.  Both loose smut and stinking smut (common bunt) can be prevented by using a seed treatment fungicide at planting.  Often these diseases occur in fields where wheat has been planted and smut has occurred before and when using bin-run wheat that has not been treated with a seed treatment fungicide.  Also notice all the yellow ‘flecks’ on these leaves which are indicative of fungal infection (most likely rust) on these leaves.

About jenreesources

I'm the Crops and Water Extension Educator for York and Seward counties in Nebraska with a focus in irrigated crop production and plant pathology.

Posted on May 19, 2017, in Crop Updates and tagged , , , , , , , . Bookmark the permalink. 2 Comments.

  1. Surprising how quickly a frost can do damage. And yet the insects remain persistent. Thanks for all the great posts to help farmers continue to learn about new situations that arise in the field.

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