Tips for late-planted corn
While warmer drier weather has enabled many farmers to get their fields planted, many corn acres are still to be planted. For those unable to plant before May 25th, NDSU researchers are recommending shifting to a hybrid that is five or more days earlier maturing than what is usually grown.
That will help ensure the grain matures before snow begins to fly, and is also not excessively wet at harvest time.
Midwestern Regional Climate Center has a support tool for deciding which hybrid corn to grow, the Growing Degree Day Decision Support Tool, located at https://mrcc.illinois.edu/U2U/gdd/.
Insects are behind too
A colder than usual spring has not only delayed farmers getting into their fields, it’s also had an effect on insect development.
North Dakota State University researchers use degree-day models to help forecast insect emergence, peak emergence, and insect growth stages.
The models are an important tool for Integrated Pest Management, helping growers to time sccouting activities and control measures.
The models may be accesses at the NDAWN website and applications — insect DD page, https://ndawn.ndsu.nodak.edu//insect-degree-days.html. Click on the map tab and select 48F for the base temperature and Degree Days for your map type.
Full rate of glyphosate needed to assure lambsquarters control
A weed escape study over the winter that looked at both the types of weeds that escaped and amounts of glyphosate required for 90 percent control, revealed a couple of surprises.
First, a majority of the escaped seed were lambsquarters, at 59 percent. Just 29 percent was kochia, and 12 percent was waterhemp. No common ragweed or redroot pigweed samples were collected.
Second, although lambsquarters was controlled by glyphosate, some samples took much longer to reach 90 percent than others. and some samples were not controlled by a 32 ounce application.
Based on the study results, producers whose most important or second most important weed is lambsquarter are advised to use glyphosate at full rates, with non-ionic surfactant and ammonium sulfate.
Repeat applications should also be considered, particularly if it is hot and dry. That makes it difficult to get good absorption through the plant’s cuticle.
Also consider using tank-mixtures with glyphosate, to deliver a second effective herbicide for lambquarters control.