More than 100 farmers from six counties in the southern end of North Carolina saw some of the best looking wheat in the state and got updates on statewide research from small grain specialists at North Carolina State University during a recent field day.
The field day, held at Wilton Shooter and Sons farm near Rowland, N.C., featured wheat weed management tips, an update on wheat diseases and fungicide options, wheat variety performance, and management strategies for high yields on sandy Coastal Plain soils.
Veteran North Carolina State University Weed Scientist Alan York kicked the meeting off with an update on wheat weed and grass management.
“The broadleaf story is pretty simple. Most folks use Harmony Extra — it’s a little broader spectrum than dicambas or 2,4D-containing herbicides. Harmony is a little easier on the wheat, and it has become the standard for wheat growers in North Carolina,” York says.
“Ryegrass control is a whole different story, he notes. In the Piedmont area of North Carolina, ryegrass has been a particularly troublesome problem. We don’t see it as much in the southeastern end of the state, but we’re getting there,” York says.
“More and more people are planting no-till wheat, and I can’t over-emphasize that they need to start clean, regardless of which grass is the problem. It just helps if you start clean, so most times they need a burn-down herbicide.
“Typically, growers with corn in the rotation don’t have a big problem with ryegrass in wheat. However, in fields with continuous wheat and double-crop beans, that’s a good recipe for ryegrass problems.
“Research in North Carolina indicates one ryegrass plant per square yard reduces yield one third of one percent. With the price of wheat, infestations at 10 plants or so every square yard provides enough economic incentive to treat,” York says.
Threshold a little fuzzy
“If you have 10 ryegrass plants per square yard it’s going to look a little fuzzy when you look out across that field. So, it’s pretty obvious when it gets time to treat with one of several herbicide options,” he adds.
North Carolina State University Wheat Specialist Randy Weisz stressed to the audience the importance of knowing how many seed they put in the ground. Wheat seed weight varies significantly and just having a set rate of seed per pound can get you in trouble, he says.
Over a period of years, he says the optimum seeding rate of somewhere between 1.3 and 1.5 million seed per acre produces the highest yields. At the low end, 1.3 million seeds is 30 seed per square and 1.5 million seed per acre equates to 35 seed per square foot.
“Unfortunately, most growers don’t plant based on seed per square foot. However, the standard practice of planting pound of seed per acre is not precise enough — not with the high cost of seed, the high cost of planting and caring for those seeds, the high cost of harvesting the crop and the final price the grower receives for the crop,” Weisz says.
“Seed sizes vary each year from field to field, year to year and variety to variety. We’ve got large seeded varieties that have 10,000 seed in a pound, compared to small-seeded varieties that have 15,000 seed per pound.”
That creates a real dilemma for growers. If they follow the North Carolina State planting guidelines of 30 to 35 seed per square foot, the seed per acre could range from 85 pounds per acre to 152 pounds per acre, depending on seed size.
“When you get ready to plant wheat this fall, look on the seed bag — it will tell you how many seed per pound in that bag. Then, you can look at page 23 in the 2011 North Carolina Wheat Production Guide and look at the conversion chart on that page,” Weisz explains.
“For example, using conventional-tillage, planting a variety with 12,000 seed per pound, it’s easy to convert that to 109-127 pounds of that bag of seed per acre,” he adds
North Carolina State Extension Associate, Georgia Love, showed the farmers attending the event the results of a fungicide timing study that visually showed the affects of applying fungicides on wheat that was in the flag-leaf stage at application.
The researchers looked at Dominion, one of the more disease resistant varieties available to growers, compared to USG 3209, which is more susceptible to diseases like powdery mildew and fusarium head blight. Fungicides used were Quilt and Twinline, applied at three different growth stages of wheat, applied at growth stage 30 only, at GS 30 and flag-leaf, and at flag-leaf only.
“Any treatment that didn’t include flag-leaf application in the tests here at Rowland had more disease. Particularly in the more susceptible variety, you can see more rust and other diseases. Whether that translates into a yield difference, we won’t know until we harvest the crop,” Love says.
Fusarium head blight or head scab produces a toxin, vomitoxin, in the head of wheat. It has become an increasingly severe problem throughout the eastern U.S., says USDA-ARS Plant Pathologist Christina Cowger.
It is becoming increasingly clear, she says, that the primary reason for the increase in incidence of fusarium head blight (FHB) is the increasing popularity of no-till wheat production.
Specifically, no-till wheat often follows corn. That leaves more corn debris in the growth environment, which provides an ideal growth site for the spores that cause FHB, she explains.
Wheat is most susceptible to FHB at the flowering stage. When wheat flowers, spores come up from corn, wheat, barley or other debris on the ground and infect the wheat head. Infected wheat typically has two fairly distinct colors — part of the grain will be bleach white and light green.
“Once a kernel is infected, it shrinks, reducing test weight and subsequently, the value of wheat. If you see a wheat head with the whiter, bleached look, that is the vomitoxin that has formed from the infections,” she explains.
Cowger stresses the time to protect wheat from FHB is during flowering. Once the vomitoxin symptoms show up, it’s too late.
North Carolina State University Professor and Small Grains Breeder Paul Murphy showed attendees to the meeting results of small grain variety tests at the Shooter Farm. He gave an overview of each variety and how it performed in these tests in Southeastern North Carolina.
The field day was co-sponsored by the North Carolina State University College of Agriculture and Life Sciences and the North Carolina Small Grain Growers Association.