Available from the UD-REC website are weed management guides for assistance in weed control in corn, soybeans, or forages.
http://extension.udel.edu/ag/weed-science/weed-management-guides/

There is a separate guide for each commodity. The first half of the corn and soybean guides deal with soil-applied herbicides and the second half is for postemergence herbicides. These guides have pre-mixes and what is in the pre-mix, expanded weed control tables, information on application timing, comments for each of the herbicides, and much more. The forage guides cover alfalfa as well as grass forages.

Working with the Delaware Soybean Board and the United Soybean Board, a herbicide classification chart is available at:
http://extension.udel.edu/ag/weed-science/weed-management-guides/

This chart groups herbicides by mode of action and site group numbers that are printed on containers and labels. The chart is designed to help diversify herbicide use by rotating effective herbicides with different sites of action to delay the development of herbicide resistance. The chart provides the number of resistant weed species in the US to each site of action, which highlight those herbicides for which we already have wide-spread resistance.

Due to the weather, a number of no-till soybean fields have not received a burndown treatment yet. As a result, many are asking about options for control. First a number of considerations:

2,4-D ester: Rate of 2,4-D may need to be adjusted. Most 2,4-D brands require a 4 week delay between application of 1 qt and planting soybeans. Rates less than 1 qt/A does not provide the same level of horseweed control. The interval between application differs with 2,4-D rates and brands. Be sure to read the label of the brand you intend to use.

Kixor products: These products have good activity on glyphosate and ALS resistant horseweed, but they have a number of restrictions due to crop safety: [Read more…]

We received a report from extension in Delaware that an adult Kudzu bug was found in a trap in Sussex County, Delaware near a kudzu patch.

This should serve as a reminder that kudzu bug is fast approaching New Jersey. This rather new pest is something our soybean industry needs to keep a watchful eye on. You may have first read in different farming publications about the presence of bean platasipid (Megacopta cribraria) or more commonly the kudzu bug in the southeastern US.  The kudzu bug has begun its migration north, having been found in Sussex county Delaware last year also. The recent find suggests that it can overwinter in southern Delaware. Kudzu bug is not only a pest of kudzu, but also soybean.

Over the past few years, a few fields have been treated with an organo-phosphate insecticide and then with an ALS-inhibiting herbicide and significant injury has occurred. A number of corn herbicides have label precautions about use of an organo-phosphate insecticide at planting due to potential crop injury. This includes the insecticides Counter (terbufos), Lorsban (chlorpyrifos), and Fortress (chlorethoxyfos). The herbicides include both soil-applied and postemergence herbicides. Some of the common products include Callisto (Halex GT); Resolve (Steadfast, Basis); Accent; Capreno, Sharpen or Kixor. Note that the list is not only Group 2 (or ALS-inhibiting herbicides). If using an organo-phosphate insecticide, a list of herbicides that have potential interactions can be found at https://extension.udel.edu/ag/files/2014/01/CornWeedguide.pdf and go to Table 19.

Unfortunately, most corn seed companies no longer designate hybrids as either IT or IR. So if you are not sure, take the cautious approach and assume the hybrid is a “standard” hybrid (no enhanced tolerance for imidazolinone herbicides); and follow the most restrictive guidelines.