By Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

I always get questions on what to use to control mornningglory in soybeans at about the time to spray postemergence. Morningglory control starts at planting with a preemergence herbicide with broadleaf products such as Canopy, Valor XLT, Envive, Fierce, Prefix, Sonic or the Authority products. These will need to be followed up with a postemergence application in a timely manner for effective control (to morningglory no larger than 3”). The preemergence herbicide slows the growth of morningglory plants and seems to “set them up” for better overall control. This has been more consistent for morningglory control than any tankmixtures or glyphosate additives that I have evaluated.

Source: Read More from Weekly Crop Update

From Weekly Crop Update

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

All winter I have been talking about Reflex as a tool for managing Palmer amaranth and other problem weeds. Farm articles from the southern US often discuss this product as well. It is commonly used for snap beans and soybeans. But it is one of those products with unique regional restrictions. On Delmarva, we are limited to one application every two years, and a maximum use of 1.5 pts. South into the Carolinas and Georgia, they can use higher rates and use it every year. North of Delaware (Pennsylvania and New Jersey) it is limited to one application in alternate years with a maximum use rate of 1.25 pts. So be sure to plan your herbicide rotation accordingly.

Source: Weekly Crop Update

From Weekly Crop Update

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Remember that the pesticide label is a legal document. Those who apply or use the products need to read the label. Changes are often made to pesticide labels, and often those changes are not well publicized. Also, not all labels with the same active ingredients have the same wording. So read the label for the specific product you intend to use. Use rates and use restrictions can vary with geography, so information you get off the internet may not be accurate for your farm. You will only know that if you read the label. UD Extension does a great job of highlighting specific points that are on labels, but we might miss a specific point that pertains to your situation. So read the label.

Source: Weekly Crop Update

From Weekly Crop Update

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

A few phone calls have come in about treating weeds in winter wheat. First, a lot of the wheat is getting to a stage where it would be injured with some of the herbicides. Also, many of the weeds are probably too large for effective control. Finally, the wheat is getting large enough that it will intercept a lot of the herbicide spray, so will you get the spray coverage you need. Each field needs to be evaluated on a case by case basis to determine if a spray should be made.

Source: Weekly Crop Update

From Weekly Crop Update
Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Updated weed management guides are available online at http://extension.udel.edu/ag/weed-science/
The Guides for “Corn Weed Management”, “Soybean Weed Management”, and” Pasture and Hay Weed Management Guide” as well as other bulletins are available.

From Weekly Crop Update
Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Some fields were sprayed last spring with Osprey for control of annual ryegrass and there was no control. At least one of these fields was confirmed as having ALS-resistant annual ryegrass. If Osprey or PowerFlex (another ALS-herbicide or Group 2 herbicide), were used for annual ryegrass but did not control them, Axial XL is the only option for ryegrass control this spring.

More fields with ALS-resistant common chickweed (resistant to Finesse, Harmony Extra, Osprey, and PowerFlex) are showing up in Delaware. Spring application of Starane Ultra is the best option to suppress/control the resistant chickweed. [Read more…]