Tuesday, March 13, 2007 10:59 PM CDT
Scouting should begin soon as winter wheat starts to green up
By SUZANNE BISSONNETTE, Pest Magement Educator
UI Extension Office
After our somewhat odd ‘no winter -- too much winter’ season, it looks as if spring really will make a showing. If that’s the case, the winter wheat in our area will green up rapidly. This has already begun just a bit south of us. Wheat scouting should start in tandem with the green up.
Virus diseases are the first diseases for you to scout. Symptoms of virus diseases are usually very clear soon after the plant breaks dormancy and begins to grow actively. The most common virus symptoms you may see are leaf tip dying and leaf yellowing, reddening or purpling. Remember that symptoms such as these can be attributed to virus infection, but may also be due to winterkill, nutrient problems or varietal characteristics.
Leaf reddening or purpling or tip die back are characteristic symptoms of barley yellow dwarf virus infection. The plants that are symptomatic now were infected by virus carrying aphids in the fall. Fall infection is much more serious in terms of yield loss compared to plants infected in the spring. Growers can expect fall-infected plants to be dwarfed and have few tillers that will likely be sterile. No in season control for virus infection exists. The only management decision that can be made is whether enough healthy plants remain to produce a reasonable stand for harvest or if the field should be abandoned and planted to another crop.
Two other viruses that cause some early season concerns are soilborne wheat mosaic and wheat spindle streak. Soilborne will typically show up in patches in low areas of the field. The mosaic symptoms are usually only fleetingly present very early in the spring, so look for these beginning now. Spindle streak on the other hand typically will show up at bit later and on the edges of the field first. Symptoms of both of these viruses are mottled or mosaic leaf discoloration and some tip die back. There is resistance to both of these diseases so knowing the resistance package of the variety you are growing can help you sort out which virus it may be.
Leaf blights may be a concern if the weather turns wet. In general, fungal leaf blights will not cause significant yield loss if they are confined to the lower plant leaves. However, as the season progresses, if the flag leaf or the flag-1 leaf is infected, a producer can expect yield losses in the range of one bushel per acre for every five percent leaf tissue that is infected.
Stagnospora leaf blight from fall infections is present on the lower leaves in some fields. Look for small tan oval lesions on the lower leaves. When raindrops hit these mature lesions spores are splashed to other parts of the plant or nearby plants in the dispersing raindrop. If rainy weather continues the disease will continue to spread up the plant. Effective fungicides are available to control fungal leaf diseases and the decision to use them should be based thorough scouting, weather forecast and yield potentials.
Soybean rust state distance education program
To help prepare soybean producers, crop advisors and other agri-business professionals for scouting, sampling, detection and management of soybean rust for the 2007 growing season, University of Illinois Extension has planned a distance education program for today hosted by many Extension offices, including Coles County across the state.
The program will be held from 8:30 am to noon.
Soybean producers, crop advisors and other agri-business professionals will hear the most current information on the biology and monitoring for soybean rust, scouting and detection of soybean rust and management strategies in the 2007 soybean crop.
Spore trapping, prediction modeling, fungicide efficacy, in-field scouting and fungicide application are just some of the many topics that will be discussed by Extension, USDA, and University personnel from Illinois and other states.
Call the Coles County office immediately if you plan to attend -- 345-7034.
Suzanne Bissonnette is an integrated pest management educator for the University of Illinois Extension.
Add your comments
Not already registered?
Then click Here.
Comment policy:
JG-TC.com encourages readers to engage in civil conversation with their neighbors. Comments that are submitted are not posted to the site immediately. They go into a queue to be moderated and may take several hours to be reviewed. Comments posted on Saturday may not be reviewed until Sunday afternoon.
In order to keep the page a set width, long lines (mostly long links) will be chopped. Try putting spaces in your links or consider using tinyurl.com to make a smaller link that you can include.
We will never edit or alter your comments, but we do reserve the right to remove comments that violate our code of conduct.
No comment may contain:
* Potentially libelous statements; such as accusing somebody of a crime, defamation of character, or statements that can harm somebody's reputation.
* Obscene, explicit, or racist language.
* Personal attacks, insults, threats, harassment or inciting violence.
* Commercial product promotions.
If you have any questions, please contact our moderator.
|
|
|
Jerry Jackson wrote on Apr 26, 2007 7:54 AM: