The challenge has become even greater since 2009, when Virginia Tech Weed Scientist Scot Hagood documented four weed species with resistance to Harmony, one of the standard herbicide treatments for troublesome weeds in small grains.                                               

Hagood  identified four fields from Virginia that had common chickweed that was resistant to Group 2 herbicides (this includes Harmony, Harmony Extra, Finesse, and others).                                                

University of Delaware Weed Scientist Mark VanGesse  says, “We have had reports of fields on Delmarva with chickweed populations not controlled with Finesse or Harmony Extra. VanGesse adds that growers with poor chickweed control and resistance to these popular weeds have few options.

Starane Ultra (from Dow AgroSciences) is labeled for wheat and barley and has been used in the western U.S. for control of Group 2 resistant weeds. However, it will not control other commonly occurring barley weed species such as wild garlic.             

Starane Ultra can be tank-mixed with Harmony Extra to broaden the spectrum of control. Starane Utra by itself does not need an adjuvant and can be applied in nitrogen.

The best weed management for barley is a good, rapidly growing, disease-free stand. To give barley the best opportunity to get up and growing quickly, most growers (no-till production) use a burndown spray of glyphosate or a similar herbicide.

Apply glyphosate after planting and before emergence of the small grain. Use a minimum of 10 gallons per acre of diluted spray. As the density of the crop residue increases, the spray gallonage should increase to ensure complete coverage and kill. Use the higher rate if existing vegetation is dense, cool temperatures exist, and/or drought conditions are prevalent.

If weeds come up after the barley crop is planted, growers can use a very carefully managed application of 2,4-D. Spray, 2,4-D when grain is 4- 8 inches high or after tillering, but before jointing. Spraying small grain too early or after jointing can result in reduced yields and uneven ripening. Higher rates of 2,4-D increase the risk of grain injury.

“Why would we want higher protein barley? We may to do that because much of Virginia’s barley crop will be used for ethanol and barley meal — a byproduct of the ethanol production process. There is a premium price and higher demand for high protein barley,” Virginia Tech Small Grains Specialist Wade Thomason explains.

“We found a few years back that we could increase the protein content of red wheat by adding nitrogen, so we instituted a test to determine whether we could do the same thing with barley,” Thomason adds.

In the Virginia Tech test they applied 30 pounds of nitrogen as urea dissolved in water, at a total volume of 37-38 gallons of water per acre. The research team will evaluate the factors involved in adding more nitrogen, including the impact on the environment, and make an assessment as to whether adding extra nitrogen to improve protein is an economically feasible thing to do.

Though the more highly publicized goal of Osage Bio’s new plant in Hopewell, Va., is to convert barley into ethanol, a big part of the economic success of the new plant will be production of high quality barley meal for livestock feed.

Hence, the interest in possibly increasing the protein content of barley. The cost of nitrogen and the negative public image of adding more nitrogen to the environment at a time when mid-Atlantic growers are trying to document their role in cleaning up the Chesapeake Bay are concerns.

Despite the big push to produce more barley, the key to increasing production is to make it more profitable for farmers. Though progress has been slow, new varieties, new production practices and continued competitive pricing will likely make barley a part of many Virginia-Maryland-Delaware farms this fall and winter.

rroberson@farmpress.com