Wheat Foliar Disease Update: April 11, 2014

To date, the wheat crop has remained relatively disease free.  I’ve been able to scout some fields in south MS over the past month and have not observed much in the way of foliar diseases.  In much of MS the wheat crop that hasn’t been killed prematurely with an herbicide due to poor stands looks good despite the cold, wet winter we’ve experienced.  Wheat fields along the Adams/Wilkinson County line south of Natchez, MS were beginning to head on Tuesday afternoon.  Some of the fields I observed this week had almost an inch or more of standing water in them around the Natchez area following a heavy rain event.  At present, I don’t suggest a fungicide application since disease pressure continues to be so low throughout MS.

Septoria leaf blotch

The only disease I’ve encountered with minimal regularity has been Septoria leaf blotch.  In the few fields where I have managed to observe this disease the infection was low in the plant canopy.  Unless Septoria appears on the flag leaf no yield loss will be associated with the presence of the disease.

Leaf rust

So far, no leaf rust has been detected in MS.  In addition, limited leaf rust has been observed throughout the U.S. to date. Reports from south LA as well as parts of TX indicate that limited leaf rust infection centers exist at this time.

Stripe rust

No stripe rust to report from MS either.  LA has reported minimal stripe rust in southern LA.  In the past, even when LA has reported stripe rust it has taken several weeks for the disease to build up enough inoculum and result in infection in MS.

Powdery mildew

I’ve received a single call regarding powdery mildew this season.  Normally speaking, powdery mildew isn’t a disease of concern unless present on the flag leaf.  In the past I’ve encountered the most powdery mildew along wooded field edges, where the planter made a double pass, and in situations where the wheat was planted in an old catfish pond.  Generally speaking, I’ve not encountered a situation where a fungicide application was necessary as a result of powdery mildew.

Fusarium head blight (FHB)

For the most up-to-date information regarding the potential of FHB developing in MS follow the information at the Fusarium Head Blight Prediction Center that can be located at: http://www.wheatscab.psu.edu/ .  Remember when using the website to click on “winter” wheat for the model (2. Choose a Model).  Also, keep in mind that in most cases the areas where FHB may be predicted have little to no wheat present.