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Are you replanting winter wheat?
Hard red winter wheat farmers in the Plains have some tough decisions ahead.
Farmers in areas where snow's fallen this winter are relatively lucky compared to their drier neighbors; that snow's keeping young plants and ungerminated seeds protected from the cold winter temperatures. Where there's no snow, the crop's hurting badly.
But, winter's not over, and the uncertainty about snowfall between now and winter's end makes for a difficult decision for farmers who may be facing a crop that needs to be replanted admist general drought stress.
"The pressing issue right now in the central and southern Plains is if they should keep their wheat crop if it's in pretty bad shape, or tear it out and plant it to a spring row crop," says Lane County, Kansas, wheat farmer and industry analyst Tanner Ehmke. "There are varying levels of failure out there, and the main question is at what level of failure do you replant?"
Some plants that have yet to germinate after a dry fall may still do so in the spring if they are protected by snowcover through much of the winter. But, yields on spring-germinated wheat like this typically fails to yield much more than 60% of normal.
So, should you replant? The best way to start making that decision is by taking a stroll through your fields and take note of the number of plants are up and still alive. How many plants you should expect depends on your original seeding rate, says Kansas State University Extension wheat agronomist Jim Shroyer.
"If a producer uses a drill with 12-inch row spacings, plants at a 60-pounds-per-acre seeding rate with a variety that has 15,000 seeds per pound, and expects a germination and emergence rate of 75% to 80%, there should be 675,000 to 720,000 plants per acre. This amounts to about 15.5
to 16.5 plants per foot of row," he says. "If a grower planted 60 pounds of seed per acre using 7.5-inch rows, and a germination rate of 75% to 80%, that would be about 9 to 10 plants per foot or row."
Conclusive scouting requires a wider field-level view, Shroyer adds. "Determine the average number of plants per foot of row that is present by taking numerous plant counts across the field. This assumes the stand is more or less uniform throughout the field, with no large gaps," he says. "Generally, if the average number of plants is about 50% or more of normal, the recommendation is to keep the stand. With less than 40% of normal, the recommendation is to replant the field. With a stand that is between 40% and 50% of normal, the decision is more difficult."
But, the decision to replant shouldn't be made without considering other factors. First, think about the conditions you might still face once the crop moves out of winter dormancy. Just because higher temperatures may pare down winterkill worries, there are still other potential setbacks, and Shroyer says they need to be accounted for in any replanting decision.
"There are 2 major concerns to consider other than yield potential in deciding whether to replant: The susceptibility of the ground to wind erosion and the potential for weed and grass infestations," he says. "Where stands are less than 40% of normal, these become major concerns, even if yield potential is not a concern."
Whether you replant wheat or opt for a different crop in the spring also may depend on your soil nutrients. Especially in a drought year, nutrients applied months ago still might be in the field, and the cost associated with taking advantage of those nutrients versus having to apply more could mean the difference between replanting wheat or turning to corn, for example.
"There are other factors to take into consideration, like all that residual nitrogen out there that the failed wheat never used," Ehmke says. "That would be best used for a spring crop. If you decide it's too dry and you wait until fall to go back to wheat again, you might lose some of that nitrogen to leaching and volatilization."
But, if you are confident that your wheat stands haven't been slammed hard enough to warrant replanting in the spring, there is one key thing to look for once spring breaks, according to Texas AgriLife Extension Service agronomist Brent Bean. If stands are thin, those plants that remain in the field have ways to compensate for yield lost by a smaller number of plants.
"The wheat plant can compensate for thin stands by increasing tillering, producing more seed per head, and increasing the weight or size of each kernel. Early in the season the best compensation factor is increased tiller production," Bean says. "However, with late emerging wheat, high tiller production is less likely. A healthy wheat plant will typically have 3 to 5 tillers that contribute significantly to yield. Under high yielding conditions and adequate spring moisture, secondary tillers can also contribute to yield, but the most productive tillers usually develop in the fall and winter."