As small grains breeder at North Carolina State University, Paul Murphy is often asked what is the best wheat variety to grow in North Carolina.
“You can’t really answer that question today,” Murphy said at the 2015 Eastern North Carolina Small Grain Feed Day held May 21 at Griffin Farms in Washington, N.C. “You could answer it 25 years ago when we had between six and 10 varieties that were being grown in the state. But the situation today is we have a large number of public and private companies producing wheat varieties for the North Carolina grower.”
Murphy said this is a good situation to be in because the development of varieties is based on a solid scientific foundation and there is a great deal of cooperation between public institutions and private companies.
“Every organization selling wheat varieties in North Carolina has good varieties,” Murphy stressed. “It’s just that some are probably better for your operation than others, depending on production problems you may have, like soil born mosaic virus or if you’re no-tiling into corn stubble or if you have a history of a Hessian fly problem.”
Yield and test weight are still the first things to think about when choosing a variety, but farmers also need to seek varieties that are resistant to powdery mildew and leaf rust which appear every year in North Carolina, according to Murphy.
“Resistance to those pests is obviously important,” he emphasized. “However, I would ask you to be careful and pay a bit more attention to two problems that we’ve seen more and more in the last four to five years. Obviously scab (Fusarium head blight), but another one that is presenting more and more problems at every location where I test is Hessian fly.”
North Carolina has seen a steady increase in Hessian fly numbers in the past five years, and Murphy believes farmers may be suffering yield losses to the pest and not realize it.
“Sometimes when people are having these 50 and 60 bushel yields, and they are saying that’s just the way it is, I’m often wondering how much Hessian fly is nibbling away at those yields,” Murphy added.
To illustrate Hessian fly damage, Murphy said his breeding nursery in Kinston this year had the heaviest Hessian fly infestation he’s ever seen with 50 percent of all the lines he had in the nursery lost to Hessian fly. “The germplasm in that nursery represents a mix of everything that is in commercial production so it gives you an idea how susceptible our material is in general. There are a lot of varieties with great resistance to Hessian fly, and I think people need to be paying a bit more attention to those varieties with Hessian fly resistance because it’s gotten worse and worse in the past few years.”
In the meantime, Christina Cowger, plant pathologist at N.C. State, stressed that planting scab- resistant varieties is a critical management strategy for wheat growers. The challenge, she said, is that most varieties available today are either moderately susceptible or susceptible to the disease.
Of the 16 wheat varieties listed on N.C. State’s small grain production website, only four of the varieties are rated moderately resistant to scab, with the rest being either moderately susceptible or susceptible, according to Cowger.
“That’s a problem because if you’re going to try to plant a large proportion of your acreage to high yielding varieties then you’re going to have trouble planting a high proportion of your acreage to scab-resistant varieties,” she said. I think it’s going to be necessary for us to vote with our feet and choose increasing percentages of scab resistant varieties even if it means paying a little bit of a yield penalty in a non-scab year.”
In years when scab is a problem, varieties with moderate resistance to the disease will be equal to or better yielders than scab-susceptible varieties, Cowger stressed.
However, Cowger said it is critical for companies and breeders to stop releasing scab-susceptible varieties. “It’s going to have to come from the demand side. People are going to have to say we don’t want to gamble with this disease anymore because it is part of life every year now.”