Winter Wheat Struggling on Plains
Date Posted: December 10, 2012
Brookings, SD—It's been a challenging fall for South Dakota's winter wheat producers as they adjust to very poor crop conditions, on the heels of a banner harvest just a few months ago.
"Sixty-four percent of winter wheat in South Dakota was rated in poor or very poor condition the last week in November.
"This rating was the worst of any state in the primary winter wheat growing region," said Laura Edwards, SDSU Extension Climate Field Specialist.
For comparison, Edwards shares that Nebraska's crop was rated 46 percent poor to very poor condition and Oklahoma was rated 44 percent poor to very poor condition during the same week.
The quick development of severe to exceptional drought, according to the U.S. Drought Monitor, has affected much of the wheat producing areas of the U.S., says Edwards.
"The winter wheat crop conditions in the central U.S. has affected the national rating, which is now at its lowest level since records of this type began in 1986," she said.
Figure 1 shows U.S. winter wheat condition ratings for the years 1995 through 2012.
It is evident that 2012 is rated much below previous drought years of 1999, 2001, 2003 and 2007.
Even though the hard red winter wheat of South Dakota is just 60 percent emerged as of 25 November, other states in the Northwestern white winter wheat belt and the soft red winter wheat belt (eastern Corn Belt, mid-South and Southeast), have fared much better.
Idaho was rated 69 percent good to excellent condition for the same week, and Washington State was rated 67 percent good to excellent.
In both Michigan and Indiana, 72 percent of winter wheat is rated good to excellent, and Ohio is currently rated 70 percent in those categories.
Figure 2 shows major and minor winter wheat growing areas, and which regions are in drought, according to the U.S. Drought Monitor map on 20 November.
U.S. winter wheat areas in drought, as of 27 November 2012.
The red stripe region corresponds with D1 through D4 categories on the U.S. Drought Monitor for the same week.
Dark green indicates major winter wheat growing regions, and light green areas are minor winter wheat regions. Image courtesy of USDA.
The fact that a large percentage of winter wheat in South Dakota is rated in poor or very poor condition is not surprising, says Bob Fanning, SDSU Extension Plant Pathology Field Specialist.
"Given the dry soil conditions into which much of the crop was planted, and the lack of moisture it has not received," Fanning said.
"Some people believe the report of 60 percent of winter wheat emerged seems high."
Fanning explains that the NASS crop progress estimates are based on a subjective opinion survey of county officials, which are not claimed to be statistically accurate.
"The important fact is that even if the figure is high, 60 percent is the lowest percent of winter wheat emerged by late November in South Dakota since at least 1990," he said.
"The only other fall that stands out with a low percentage of winter wheat emergence in South Dakota was 2000, when 74 percent of the crop was reported emerged in November.
"The statewide average yield in 2001 was 32 bushels per acre, which tied for the second and third lowest yield over the past 22 years. It is not advisable to make yield predictions for the 2013 cropping season based on this however."
Many areas where winter wheat was planted into dry soil have received small amounts of moisture via rain and/or snow.
This limited moisture has caused some of the wheat to sprout, but little has actually emerged to a significant degree.
"These seedlings have used energy reserves from the seed, and have not been able to generate photosynthetic activity and develop crowns to store energy for winter survival.
"Without additional moisture, the sprouted seedlings may dry out and die," Fanning said.
Dry soil cools off more quickly and will get colder than soil with adequate moisture.
"If low air temperatures occur without snow for insulation there is potential for exposure to low temperatures which could contribute to significant winterkill for a crop in marginal condition," Fanning said.
"Moisture in the form of either rain or snow would improve the condition of the crop and chances for its survival. However prospects for moisture don't look good."
Fanning says producers may want to wait before making management decisions, such as fertilizing, until they have a better handle on the potential of the crop.
"As spring approaches, winter wheat growers would be advised to get out in their fields, assess the condition of the crop and consider contingency plans.
"If the crop is insured, producers should contact their crop insurance agent before taking steps to terminate the crop and initiate alternative plans," Fanning said.
The good news, Fanning says, is that if the crop survives, it is almost certain that the plants will vernalize and produce a seed head.
"All that is necessary for the winter wheat plants to vernalize is for the kernel to take on moisture and swell, and go through a period of about three weeks at about 40 degrees or lower.
"It is almost unheard of for winter wheat planted in the fall in South Dakota to not complete that process," Fanning said.
"It is well known among producers that wheat, particularly winter wheat, is a tough crop and can surprise you with its resiliency."
For more information, call 605-688-4148.