Although we were not hit as hard by the drought as other states, there is some evidence of diseases coming in on some ear tips from those fields that were significantly effected by the drought and are still awaiting harvest . The Plant Management Network, publisher of the Focus on Corn webcast resource, is re-opening two webcasts through December 31, 2012: “Ear and Kernel Mold Biology and Management” by Dr. Charles Woloshuk at Purdue University and “Corn Storage” by Dr. Ken Hellevang at North Dakota State University. [Read more…]

Weekly Crop Update

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

Fall herbicide treatments have a nice fit for many situations such as small grain weed control, assisting with cover crop management, and reducing the severity of weed infestations for no till corn or soybeans.

Let’s look at each of these situations. Treating small grain fields with a late fall herbicide application has worked well in our trials. As discussed in earlier newsletters there are no herbicides labeled for applications at planting (a preemergence application). As a result we have lots of winter annuals that emerge with or shortly after the crop. Waiting until spring to control these weeds often results in poor control because the weeds are large, and often stressed from the winter weather. On the other hand, an application in the late fall is made while the weeds are relatively small and actively growing. Remember these weeds are winter annual and will continue to grow after a few hard frosts, and the soil temperatures allow for significant growth through the month of November. If there is a lot of spring emergence, then those weeds can be controlled with a herbicide applied in combination with spring nitrogen applications.
Source: Read more from Weekly Crop Update

By WCU Editor

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

A few herbicides are labeled as harvest aids for soybeans. Glyphosate and paraquat will have the broadest spectrum of control, with paraquat having quicker activity on the weeds. Aim is also labeled, but it has a very narrow spectrum of control. Be sure to read the label of the product you are considering for all the precautions and restrictions. Application of these products is after the pods begin to lose their green color. Applications made this late in the season means they will have little to no impact on reducing weed seed production.
Source: Weekly Crop Update

By WCU Editor

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

For no-till fields, a non-selective herbicide needs to be used prior to planting. If grasses are present glyphosate is a better choice than paraquat. Fields worked with a vertical tillage implement for residue management still need a non-selective herbicide. These implements are not weed control tools.

There are few effective herbicides labeled for preemergence applications. Sharpen is labeled but we have limited data in the region to recommend it for either residual weed control or crop safety. Valor can be used at 1 to 2 oz with the burndown application, but there must be a 30 day period between application and planting wheat due to concerns with crop safety.

A few products can be used shortly after the crop has emerged. Axiom and Prowl H2O can be used at crop emergence (Axiom at the spike stage and Prowl H2O at 1 leaf stage); however they need to be tankmixed with other herbicides or followed by postemergence herbicides to provide a broad spectrum of control.

Products that provide postemergence control include: Harmony, Harmony Extra, Starane Ultra, Osprey, PowerFlex, Axial XL, 2,4-D, or dicamba. Others labeled with a limited fit include metribuzin, Finesse, and Maverick.
Source: Weekly Crop Update

-Stephen Komar
I have seen a marked increase in the number of pastures and hay fields infested with Horsenettle this season. This weed is a major concern since it can limit the marketability of hay due to the sharp prickles found on the stem and can quickly take over a field due to the large number of seeds produced and spreading rhizomes. Fall herbicide applications can be effective in managing this weed.
For more information, please visit the Mid-Atlantic Pasture Management Guide.

By WCU Editor

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

Corn harvest has begun in some areas and the drought has resulted in large areas with stunted plants and very poor leaf development for shading weeds. Both of these situations have created conditions for late season weed growth that could result in significant weed
Source: Weekly Crop Update