ENID, Okla. —
The wheat crop in much of northwest Oklahoma has experienced many problems this year.
It is about two weeks behind normal in development, shorter than normal (on dryland fields at least), has a shortened flag leaf, and/or has a poorly developed root system. In addition, most fields still are under drought stress, have freeze injury or suffered winterkill damage. If wheat remains under drought stress and the weather turns unusually hot, producers can expect to see the following symptoms:
• White heads, which can develop quickly.
• Curled and dried up flag leaf.
• Sloughed tillers.
• Loss of one or more small developing kernels in the spikelet.
• Poorly developing kernels.
• Chlorotic leaves due to poor root development and nutrient deficiencies.
From the boot stage through heading and grain fill is a period of high moisture use, with wheat using about 0.25 to 0.30 inches of moisture per day. If the moisture is not available, the wheat will begin to show the symptoms listed above. The combination of dry soils and heat, in particular, will cause heads to turn white rather quickly, almost overnight. Any additional stress, such as diseases or insects, will just add to the stress.
If temperatures are cool to moderate in the coming weeks and rain comes to stressed wheat sometime before the flowering stage, the wheat may be able to recover some yield and test weight potential as long as the flag leaves still are alive. If the plants are under severe stress and shut down while kernels are in the early dough stage, it is unlikely any subsequent rain will help the kernels complete their fill. This will result in a loss of yield and low test weight regardless of the weather during the remainder of the season.
The drought this year has resulted in short flag leaves in many cases, and reduced the overall photosynthetic potential of the wheat. All of this will have an effect on grain fill, yields and test weight.
Drought-stressed wheat already is shorter than normal. In some cases, these plants may eventually recover if they get some rain by the boot or early heading stage — even wheat that turned blue from drought stress. But yield potential will be reduced. In severe cases, however, some of these plants may turn brown and die.
Plans for the 2014 North Central Research Station Wheat Tour located one mile west of Lahoma on U.S. 412 have been finalized for Friday. Registration will begin at 8:40 a.m. Coffee and doughnuts are sponsored by Oklahoma Wheat Growers.
The trailers will load at 9:30 a.m. for 20-minute stops at four locations hosted by various Oklahoma Agriculture Experiment Station researchers and Oklahoma Cooperative Extension Service specialists. Lunch will be provided by Farm Credit of Enid, and dessert provided by Warren Cat for those who RSVP to (580) 237-7677. A complete tour agenda is available at http://oces.okstate.edu/garfield .
Garfield and Major County OSU Extension Service will sponsor a tractor safety school for youths 14 to 16 years old who plan to drive a tractor for employment. Classes will be held at the Garfield County Extension Center, 316 E. Oxford, on May 2830. For registration and information, call (580) 237-1228.
Nelson is Oklahoma Cooperative Extension Service ag educator for Garfield County.