Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu, Nathan Kleczewski, Extension Specialist – Plant Pathology; nkleczew@udel.edu, Mark VanGessel, Extension Weed Specialist; mjv@udel.edu, Bill Cissel, Extension IPM Agent; bcissel@udel.edu
This was the final season of our Small Grain IPM project addressing the following two objectives: (1) aphid and barley yellow dwarf virus (BYD) management and (2) weed management of newly emerging weeds and resistance management. Yearly summaries of our statewide survey results (2013-2016) for aphids, BYD and weeds can be found on our IPM webpage (http://extension.udel.edu/ag/insect-management/e-ipm-implementation-projects/).
In addition to the reports, we also developed the following educational materials to address monitoring and management of aphids, BYD, and weeds in small grains:
BYD Management in Small Grains (fact sheet)
https://cdn.extension.udel.edu/wp-content/uploads/2015/10/14051904/BYDV-Final-Draft-9-12-16.pdf
Scouting for Aphids in the Fall in Small Grains
https://www.youtube.com/watch?v=He3nTpL6k_U&nohtml5=False
Photo Library of Aphids Infesting Small Grains
https://www.flickr.com/photos/139973317@N03/sets/72157664513242564/
Photo Library of BYD Virus Symptoms in Small Grains
https://www.flickr.com/photos/139973317@N03/sets/72157666301880210/
Weed Management Guides (regional publication)
http://extension.udel.edu/ag/weed-science/weed-management-guides/
A couple of key findings:
- Although BYD incidence levels were relatively low throughout the state, there were fields where management should be considered. The best management options are to avoid early planting, use an insecticide treatment if you do plant early (NOTE – seed treatments only will provide 2-3 weeks control), ensure a good burndown of all grassy weeds that could be a host for the virus at least 2 weeks prior to planting, and selection of a tolerant variety.
- The “experimental” thresholds that we tested from the South appear to be too low for our area. Unfortunately we do not have any research based aphid thresholds for fall management of aphids. Foliar aphid controls may be considered if you have a history of BYD in your fields, aphids are present and factors occur that increase the risk of BYD (early planting, use of a BYD susceptible variety, proximity to pastures or large wooded areas , late warm fall and/or early warm spring)
- Surveying small grain fields in the fall last past three years we found henbit and common chickweed to be the two most common species (in almost 90% of the fields); field pansy and annual bluegrass were present in 60 to 65% of the fields, and cress (a small mustard species) and ivyleaf speedwell were found in 30 to 40% of the fields. See the following article for more information on managing some of these common species.
We hope you find these resources useful. We will be looking for your input this fall after you have had time to review the information. In the meantime, if you were able to watch the aphid scouting youtube video , please consider clicking on the following survey link and answer two poll questions https://www.surveymonkey.com/r/75BRV9W