Winter wheat was at risk depending upon stage of development when the super-warm March returned to a near-seasonal April, with a few nights of low temperatures that approached freezing in some areas. Whether or not yield potential was affected much depends what stage the wheat was in, notes Shaun Casteel, a Purdue University agronomist who specializes in soybeans and wheat management.
Most of the injury Casteel was told about or asked to inspect consisted primarily of leaf tip burn, he notes. He believes that if that is the extent of the damage, then there should be little if any yield loss due to the freeze. The exception may be an occasional field that was farther along in development and which may have suffered severe injury. Since this isn't seen all that often, time will tell how those few fields react, he notes. Casteel advises scouting wheat fields at any rate to make sure you know what crop prospects you have as the season unfolds.
One report from an independent agronomist says that when he was called to inspect freeze injury, it really turned out to be primarily a case of not enough N applied to the wheat, or else excessive N losses due to wet soils. Since wheat is a grass, it responds to nitrogen. Most experts recommend around 100 pounds per acre or N. Some N may go on in the fall to help get the wheat started, but most is applied in the late winter or early spring, either as liquid N or as granular urea spread on the field,.
The symptoms of nitrogen shortage are distinct and much like those for corn, the agronomist syas. Plants will be spindly and yellow. This is a distinctly different appearance that what would be linked to frost or freeze injury, he notes.