As wheat harvest begins or nears across the Southwest, farmers anticipate production will range from near-record yields to near disaster, depending on rainfall amounts and timing of rain events. Wheat observers from Texas, Oklahoma and Kansas report that the 2012 crop will be earlier than normal.
“If the weatherman is not lying, I expect harvest in Southwest Oklahoma to be largely wrapped up by the end of this week,” says Oklahoma State University Extension wheat specialist Jeff Edwards.
“Combines will be well into central Oklahoma by next week. My prediction is that the state average will come in at about 36 bushels per acre. If we had gotten rain a little sooner, I think this could have easily been well above 40 bushels per acre.”
Edwards says drought and heat were the primary factors influencing state wheat yields. “Even though wheat fields looked good from the highway, most of our crop endured some pretty significant heat and drought stress this year. Several tillers and most ‘3rd berries’ were aborted as a result.”
In-season problems included:
- Stripe rust. “We are dealing with a new race. Previously resistant varieties Armour, Everest, and Pete were hammered in some areas. Some of the newest varieties such as Garrison were not hit as hard, but it can no longer be called completely resistant.”
- Lodging. “The mild winter resulted in three to four times the normal number of tillers. Combined with high levels of residual nitrogen from the failed crop of 2011 and high winds during April, this created the perfect situation for lodging. I saw quite a bit of 70-bushel wheat reduced to 30- to 40-bushel wheat due to lodging.”
- Barely Yellow Dwarf Virus. “We had a flush of aphids around late March. They brought barley yellow dwarf virus that showed up as yellowing and purpling about the time flag leaves were emerging.”
- Weeds. “Weed control was better than in previous years, but we have a long, long way to go. Wheat yields are not going to improve much until we get weeds under control. Timely scouting, fall (herbicide) application and crop rotation are the keys to getting the job done. If you have weeds in mid March, you have already lost the battle. You might still be able to kill the weeds, but it is a revenge operation. They have already stolen nitrogen, water, and sunlight from your crop, and it will not regain full yield potential. Again, timely scouting, fall application and crop rotation are the keys.”
In Texas, some wheat producers will harvest one of the best crops they’ve seen in years, maybe ever. Other areas have been hammered by a prolonged drought and will see poor yields.
“Wheat across the board is very early this year, typically two to three weeks ahead of ‘normal,’” says Travis Miller, associate department head and Extension program leader, soil and crop sciences department at Texas A&M.
“I am told there was wheat harvest starting in South Texas (near Uvalde) on April 25. I saw a field being harvested in Robertson County on May 4. As projected, wheat yields are generally good to excellent where the rain fell, although I have heard of a few disappointments along the coast. Recent rains in the San Angelo area will slow harvest for a few days.”
Miller says wheat producers east of a line running from Vernon to about 30 miles west of Abilene “will have above average wheat (perhaps with a few exceptions). West of that line, wheat is short and thin and yields will be generally poor. I have participated in tours in Uvalde, Hill, McLennan, Johnson, Concho and Taylor counties, and all have good wheat that will be harvested early.”
Extension agronomist Jackie Rudd, Amarillo, says the wheat crop in the Texas Panhandle is about two weeks ahead of schedule. “Harvest could start the first week of June. Most irrigated fields look good while dryland fields are quite variable. Generally, the stands were fair in the fall but subsoil moisture was very limited. Winter and spring moisture events were spotty. Some areas were adequate and some were dry.”
He says rainfall earlier this week “may help finish fields that still have a green leaf, but most dryland fields I have seen are already near maturity and won't benefit much. There were some reports of greenbugs, rust, and viruses,but these were not widespread.”
Rudd says the main yield-limiting factor was water. “East of Amarillo is generally better than west. Overall, I believe yield will be slightly below average in the Texas Panhandle, which is considerably better than the outlook last fall.”
Perhaps the most promising area for Texas wheat remains the northeast corner of the state, where conditions have been almost ideal since last fall.
Jim Swart, Texas AgriLife Extension integrated pest management specialist, says early harvest reports indicate hard red winter wheat yields at 60 bushels or better. Some soft red winter wheat yields have topped 80 bushels.
“We’re just getting started,” he says.
Eric Williams, who farms near Aberfoyle, Texas, says the best yield he’s heard so far is 89 bushels per acre.
Swart said earlier in the spring that the 2012 wheat crop in the area could be one of the best on record.
Wheat fields in central and western Kansas could use at least one last good rain before harvest.
“Wheat is under stress in much of western Kansas south of I-70 and west of Pratt and Great Bend,” says Kansas State University’s Jim Shroyer. “In areas east of U.S. Highway 281, there are fields where wheat is under stress, especially on terrace tops.”
Shroyer, a crops specialist with K-State Research and Extension, says stressed wheat is generally showing some combination of the following symptoms:
- White heads, which developed very quickly over a wide area;
- Curled and dried up flag leaves;
- Tillers that have sloughed;
- Loss of one or more small developing kernels in the spikelet;
- Poorly developing kernels; and
- Chlorotic leaves due to poor root development and nutrient deficiencies.
Shroyer says stress came on quickly this year.
“There were general rains earlier in the spring and topsoil moisture was adequate in most areas until recently. But where subsoils were very dry after last summer’s drought, wheat needed a regular supply of rainfall events this spring to support the top growth. Where that didn’t happen, wheat quickly became stressed, especially during periods of extreme heat this spring – the latest being May 4 and 5.”
During heading and grain fill—a period of high moisture use—wheat uses about 0.25 to 0.30 inches of moisture per day. If moisture isn’t available, wheat will show symptoms, Shroyer says. The combination of dry soils and heat, in particular, will cause heads to turn white quickly, almost overnight. Any additional stress, such as diseases or insects, will add to the stress.
He says although cool weather has returned the crop still needs another rain or two where it is dry.
“If rain comes to stressed wheat while the kernels are still in the milk stage of development or earlier, the wheat may be able to recover some yield and test weight potential as long as the flag leaves are still alive,” Shroyer says. “If the plants are under severe stress and shut down while kernels are in the early dough stage, it is unlikely that 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.”
Other reports indicate that all districts across the state have seen at least some wheatturning color as the crop continues to progress three weeks ahead of normal. Statewide, 98 percent of the wheat crop has headed, well ahead of 55 percent last year and the 5-year average of 46 percent. With the crop in the South Central and Southeast Districts already at 50 percent turned color earlier this week, the state averaged 26 percent turned color.
Since precipitation continued to be scarce in many of the principal wheat growing districts, condition of the wheat crop continued to decline to 5 percent very poor, 11 percent poor, 32 percent fair, 41 percent good, and 11 percent excellent. Insect damage decreased slightly to 18 percent light, 5 percent moderate, and 1 percent severe. Disease damage was nearly unchanged at 28 percent light, 16 percent moderate and 4 percent severe.