US Winter Wheat At Risk Of Freeze Damage

The US winter wheat crop will be exposed to potentially damaging temperatures Monday night when temperatures fall into the low and mid 20s F, say StormX.

Injury to jointing wheat will occur when temperatures fall to the mid 20s F for at least 2 hours, long enough to kill the growing point that is located above the soil surface, they say. The stem growth will stop immediately above the growing point and yield losses will vary, depending on the extent of freeze damage in the affected stems. Mild stem injury does not appear to interfere with ability of wheat plants to take up nutrients from the soil and translocate them to developing grain, according to research conducted by Kansas agronomists.

Jointing was just beginning in Kansas on March 26th, reportedly 9% under way in the south-central district and 15% in central Kansas. Jointing was most advanced in the southwest district at 20%. Minimum temperatures tonight are expected to bottom out in the low to mid 20s F in Wichita (23), Dodge City (25), Garden City (22), Hutchinson (20), Medicine Lodge (23) and Liberal (22). These cities are all located in the southern half of the state.

Vulnerability to freeze damage is greater in Oklahoma, where crop development is more advanced. Statewide 62% of Oklahoma wheat was jointing March 26th while a few fields in the southwest part of the state had already reached the boot stage. Predicted lows for tonight are: Enid (22) Hobart (29) Lawton (26) Ponca City (24) and Stillwater (24). Temperatures will rebound into the low 40s F Tuesday night in Oklahoma and Kansas.