Thursday, June 9, 2011

Wheat Virus's not too late!

If you are a Colorado wheat grower and your wheat is looking a little yellow or sickly, we are offering again this year (at no charge to the grower/submitter) to test wheat samples for five different viruses (virus screen).  We test for Cereal Yellow Dwarf Virus-rpv (CYDV-rpv), Barley Yellow Dwarf Virus-pav (BYDV-pav), High Plains Virus/Disease (HPV), Wheat Streak Mosaic Virus (WSMV) and Triticum Mosaic Virus (TriMV).  It's not too late to submit your samples to the Diagnostic Clinic this season.  Samples should contain at least 4-5 symptomatic plants so that we have enough leaf material to test.  Information included with the sample should include location of the field, county, variety of wheat (if known) and contact information of the grower or submitter so that we can let you know what the results were.  Our mailing address is Plant Diagnostic Clinic, E215 Plant Sciences Bldg, Colorado State University, Fort Collins, CO  80523-1177.  If you would like to call and let us know a sample is on the way, our phone number is 970-491-6950. 

Tuesday, June 7, 2011

Wind vs Tree.........

Yesterday here in Fort Collins, about 3 p.m., we experienced a microburst wind event with a bit of rain.  Didn't think too much of it, as this happens quite frequently as temperatures start to warm up and high and low pressure areas collide.  However, it did some damage on campus.  A mature linden tree, approximately 40 feet in height was apparently blown over by the wind.  On closer inspection, it appears there may have been some pre-disposing factors that contributed to the demise of the tree.  It looked like it was planted incorrectly and there was some butt rot involved.  I'm posting photos of the trunk and the entire tree for you to decide. 
 Luckily no one was hurt nor was any property damaged, i.e. cars, etc.  Above photo is of the complete fallen tree as taken from the east side of NESB.

Left photo:  Looking southeast from NESB


Monday, June 6, 2011

Colorado Wheat Update

The wet, cool weather most of the eastern part of the state experienced the past week or more was very conducive to stripe rust development. Yet, I still have not had any confirmation of stripe rust in the state. However, Dr. Bob Harveson, U. Nebraska reported stripe rust in an irrigated wheat field from western Scotts Bluff Co (south of Morrill). Therefore, it is entirely possible there are ‘hot spots’ of rust out there. If you have seen stripe rust, please email me with some images or send me some samples. The weather outlook for the next week isn’t that favorable for stripe rust development so I am hoping we are in the clear. Remember if you decide to make a fungicide application (which I am not advocating), make sure you follow the label concerning plant harvest intervals.

We have received a smattering of virus disease samples. Barley yellow dwarf is fairly common with some wheat streak mosaic. But we certainly don’t have the virus problems of some previous years.

Ned Tisserat

Extension Specialist and Professor

Wheat Disease Update from Oklahoma

Wheat Disease Update –06-Jun-2011

Bob Hunger, Extension Wheat Pathologist

Department of Entomology & Plant Pathology

Oklahoma State University

Oklahoma: Harvest is occurring or starting across all of Oklahoma, so observations and reports of disease occurrence are about at an end. The only disease observations that have come to my attention are a number of samples from the OK panhandle that came into the diagnostic lab last week and tested positive for various combinations of wheat streak mosaic virus, wheat mosaic virus (high plains virus), Triticum mosaic virus, and barley yellow dwarf virus. This is similar to the panhandle of Texas where Dr. Jacob Price (Plant Pathology Research Associate, Texas AgriLife Research, Amarillo, TX) has reported that, “During this wheat season 214 samples were submitted to the GPDN diagnostic lab in Amarillo from counties in the northern Texas Panhandle. Of these, many were found to be infected with single and multiple infections of Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), Wheat mosaic virus (WMoV), and Barley yellow dwarf virus (BYDV). The most prevalent viruses found were WSMV and BYDV at 31 and 21%, respectively. Thirteen percent of samples were found to be infected with TriMV and of these samples 93% were also infected with WSMV, as has been seen in previous years. Only 4 and .01% of the samples were found to be infected with WMoV and CYDV, respectively. These results are similar to previous years.”