The best way to determine what wheat variety to plant in North Carolina is to turn to the North Carolina Official Variety Test, advises Paul Murphy, North Carolina State University small grains breeder.
Speaking at the 2016 Northeast Ag Expo Small Grains Field Day at D&S Farms in Elizabeth City Feb. 25, Murphy said the OVT “green book” comes out in July or August of each year and summarizes varietal performance at six locations across the main wheat producing regions in North Carolina. The results are also available online at www.ncovt.com.
The OVT plots are located in Rowan and Union Counties in the Piedmont, Robeson and Lenoir Counties in the Coastal Plain, and Perquimans and Washington or Beaufort Counties in the Tidewater.
In addition, Christina Cowger, a researcher with USDA’s Agricultural Research Service and associate professor in the Department of Plant Pathology at North Carolina State University, and Ron Heiniger, Extension cropping system specialist at N.C. State also prepare a two-page summary of the wheat OVT.
The “2015 Wheat Variety Performance and Recommendations” ranks the varieties over two years into above average yielding, average yielding and below average yielding. The summary also ranks the resistance of varieties to insects, pests and diseases as well as test weight and maturity. “It is a very valuable tool with important information,” Murphy said.
Murphy said disease resistance is critical when selecting a variety. As he has emphasized in previous field days, Murphy said fusarium head blight or scab is the biggest disease threat to North Carolina wheat.
“Pay attention to the scab resistance of the varieties you’re planting. It will save an awful lot of tears in the whole wheat industry if we could get more acres of scab-resistant varieties,” Murphy stressed.
In addition to selecting varieties with good disease resistance, Murphy said North Carolina wheat farmers should pay attention to Hessian fly when selecting varieties. Scouting and managing for Hessian fly is becoming more important. “People have Hessian fly more frequently than they realize,” he said.
High yield doesn't always come to profit
Cowger also spoke at the field day and explained that even though scab-resistant varieties in the green book may not be the highest yielding lines, they should still prove as profitable for farmers when they calculate the costs of having scab-susceptible varieties.
For example, Cowger said farmers can save money by reducing fungicide applications when they plant scab-resistant varieties rather than scab-susceptible varieties.
“It’s worth it to consider the profit implications of your scab management program and not just assume that the highest yielding varieties are always going to be the most profitable ones,” Cowger stressed.
When choosing a variety, Murphy said it is also valuable to consider how past OVT data can predict future performance. In an analysis, Murphy took OVT data from 2011, 2012 and 2013 and determined how the data would predict varietal performance in 2014.
“Is what you see in the previous data what you get in 2014?” Murphy asked. “My definition of accuracy was if a variety is in the upper half of the above average yielding category over the previous years, is it in the same category when it is grown next year.”
The statewide data in 2011, 2012 and 2013 showed an accuracy rating of 77 percent for the same varieties grown in 2014, according to Murphy. The rating means that the probability is 77 percent that the variety was going to be average yielding across the state in 2014.
“Seventy-seven percent is pretty good. I’d like it to be 100 percent, but we probably could never do that,” he said.
A valuable exercise is to compare statewide performance to how varieties perform regionally, Murphy said. For example, in his analysis, he examined the rating of varieties in Perquimans County in northeastern North Carolina. His analysis shows a 73 percent accuracy rating for the same period in Perquimans County.
“To predict how a variety is going to perform in Perquimans County, you’re really better off to first look at how they perform over these whole range of environments across the state,” he said. “The varieties of wheat we are growing are generally broadly adapted within the North Carolina environments so something that does well down in Union or Robeson County has a good chance of doing well up here in Perquimans County.”