This is the time for wheat producers to be in the field fertilizing and controlling winter annual weeds, according to a Texas AgriLife Extension Service specialist.
Dr. Brent Bean, AgriLife Extension agronomist, said producers need to apply top-dressed nitrogen prior to wheat jointing, which is usually around March 15 in the High Plains and South Plains.
“Jointing may be earlier this year because of the warm February we’ve had,” Bean said.
Just prior to jointing is when the wheat spike or grain head forms and kernels in the head develop, he said. In addition, applying fertilizer now could promote late tillering or at least prevent aborting of tillers already present.
Bean said he typically recommends 1.5 pounds of nitrogen per bushel of anticipated yield, so 60-bushel wheat would require 90 pounds of nitrogen.
“If a soil test has not been done, you should assume you have 25 pounds of residual nitrogen in the soil,” he said. “This residual nitrogen should be subtracted from the amount you think you need for your yield goal.”
Either dry or liquid fertilizer can be used, Bean said. And as long as temperatures are mild (less than 80 degrees), nitrogen loss due to volatility will be minimal.
“Ideally, you should watch the forecast and fertilize just prior to a rain,” he said.
Bean also said this is shaping up to be a very bad year for winter weeds, and producers might consider applying herbicide as they go over the field applying the fertilizer.
“Keep in mind that when mustard weeds are small and in the rosette stage they are much easier to control than after they bolt,” he said. “Also, the longer the weeds are there, the more soil water they are using.”
Many herbicides will control the most common mustards in wheat, Bean said. But the tougher-to-control weeds like prickly lettuce and kochia will require special attention when it comes to herbicide selection.
“In general, choose a herbicide based on how long you want it to last in the soil,” he said. “For example, 2,4-D will generally do a good job of controlling small mustard weeds but has no soil residual. Other weeds can emerge after the application that will not be controlled.”