Producers in Oklahoma and surrounding drought-ravaged states who are deciding whether or not to dust in wheat should remember that planting practices will not be business as usual.
“Normally, the situation faced by growers when dusting in wheat is dry topsoil with adequate subsoil moisture,” said Jeff Edwards, Oklahoma State University Cooperative Extension small grains specialist. “If all goes well, the wheat will germinate when rain occurs and wheat seedlings quickly discover the subsoil moisture below.”
Germinating wheat seed will remain viable if it dries out early during the germination process. However, once the coleoptile – the pointed protective sheath covering the emerging shoot – extends to the soil surface, the plant must have sufficient moisture to continue growth or it will perish.
Edwards said he was not a big proponent of dusting in wheat during September because the state did not have the subsoil moisture needed to sustain a thick-sown wheat crop.
“October should bring cooler temperatures that will help stretch rainfall further and make dusting in wheat a more attractive option,” he said. “This will not eliminate the possibility of wheat emerging and then running out of moisture, but it will lessen the probability.”
Key points for dusting in wheat include:
- Plant shallower than normal, approximately a half-inch deep;
- Keep in mind that ridges formed by narrow press wheels can make “effective planting depth” much deeper if they fill in during a heavy rain event;
- Be cautious with in-furrow nitrogen or potassium, as these can make it more difficult for the seedling to absorb water for germination; and
- Consider in-furrow phosphorus to give young seedlings a boost, as this can be especially important for late-emerging seedlings.
“Wheat doesn’t require much nitrogen in the fall,” Edwards said. “Delaying the bulk of nitrogen applications until topdress times can be an effective way of deferring expenses until an acceptable wheat stand is assured.”
Edwards added that wheat emerging in October should still have full yield potential.
Wheat emerging in November or December will have approximately 50 percent to 75 percent of full yield potential.
“Although always important, producers need to take stock of what is best for their operation in the short and long terms, especially given Oklahoma’s recent exceptional drought conditions and weather forecasts for the coming year,” Edwards said. “An alternative to dusting in winter wheat for some producers may be to allow soil moisture to build and plant a summer crop next spring.”