Wheat disease updates are written by Dr. Bob Hunger, OSU Extension Plant Pathologist

Oklahoma:  Diseases are still quiet across Oklahoma.  Gary Strickland (Extension Educator – southwest Oklahoma) indicated he has “seen one leaf rut pustule.”  Also, wheat just has not grown in his area and is just starting to get to the point of tillering but there is so little growth he doesn’t feel there is sufficient growth to support much tillering.  He did indicate he has seen and has a lot of reports of brown wheat mites.

Around Stillwater, the wheat soilborne/spindle streak mosaic is the only disease of prominence.  I did find some small pustules of powdery mildew in the extreme low leaves of ‘Pete’ wheat that was in the range of Feekes 6.  Wheat around Stillwater is in much better condition than in western Oklahoma where drought has been severe.  I also have seen quite a few lady beetles in my trials and plots, but have yet to see any aphids.

Reports/excerpts of reports from other states:

Arkansas  Dr. Gene Milus (Professor/Wheat Pathologist, Univ of Arkansas) 20-Mar-2014:  Jason Kelley, Extension wheat agronomist, found fresh leaf rust pustules on volunteer wheat at the Cotton Branch Experiment Station near Marianna on March 20.

Louisiana Dr. Stephen Harrison (Professor/Wheat Breeder, LSU AgCenter) 18-Mar-2014:  I found leaf rust at the Ben Hur Research Farm in Baton Rouge yesterday.  This was in an early-planted field for Hessian Fly where I found a few pustules around Christmas.  The cold and very wet winter put the rust on hold until recently but it is active and should ‘take off’ now.  I have not received any other rust reports from around the state but will check nurseries in north Louisiana tomorrow.

The wheat crop is a little later than normal and has a much tighter range of heading dates due to the cold winter.  The variety trial probably averages second node but is very rapidly developing.

Wheat disease updates are written by Dr. Bob Hunger, OSU Extension Plant Pathologist

Oklahoma:  No foliar diseases of significance to report in Oklahoma.  Wheat is mostly just coming out of dormancy, and cold/dry conditions have not favored initiation of foliar diseases.  My soilborne/spindle streak nursery is starting to show symptoms of these virus diseases.  The wheat is just starting to “green-up,” so symptoms of this virus complex will become evident over the next couple weeks if a susceptible variety was planted in areas where these diseases are present.

Reports/excerpts of reports from other states:

Texas Dr. Amir Ibrahim (Prof, Small Grains Breeding and Genetics, Texas A&M University) 07-Mar-2014:  Our rust evaluation nursery was planted at Castroville, TX, about 12 miles west of San Antonio.  The wheat crop is now at Feeks stage 7‐9.  There is a mild buildup of leaf rust (Puccinia triticina) in the lower canopy of the spreader rows throughout the field. At this time last year, leaf rust was already 50S on ‘TAM 110’. The unusually cold weather that we have encountered this year did not favor rapid spread, but the disease seems ready to move if the weather starts to warm up.  Stripe rust (Puccinia striiformis) has been detected on some plots located in the middle of the field, and is mostly limited to a 600 ft2 area. Night temperatures for next week will range from 39 – 48 F, which will favor new infections by urediniospores and pick up in sporulation.

Wheat soilborne mosaic virus can cause yellowing in the spring in susceptible varieties such as the one on the left.