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.