LINCOLN, Neb. -- Nebraska wheat growers can protect 2007's wheat yields and grain quality by planting certified, treated and resistant wheat seeds, a University of Nebraska-Lincoln plant pathologist said.



This year, several counties in southern Nebraska reported stinking smut, also known as common bunt, said Stephen Wegulo, plant pathologist in the university's Institute of Agriculture and Natural Resources. Grain contaminated by stinking smut, which derives its name from a strong, fishy odor associated with the infected wheat kernels, can be rejected by the elevator, often resulting in total crop loss.



"The pungent odor associated with contaminated grain causes livestock to reject it, significantly reducing its feed value," he said. "In addition, the compound responsible for the odor, trymethylamine, has potential to cause explosions in combines and elevators when present in appropriate concentrations."



Using farm-saved or bin-run seed most likely will result in poor variety purity, a low germination percentage, poor stand establishment, and disease, insect and weed problems, he said.



"The importance of using clean, certified and treated seed cannot be overemphasized," Wegulo said.



Total loss can result if grain is heavily contaminated with fungal spores, and additional costs can be incurred in treating diseases, insects and weeds resulting from use of low-quality seed.



"In terms of dollars, the return from using clean, certified and treated seed will almost always exceed the cost of the seed," he said. "It's an insurance that is definitely worth the cost."



Stinking smut is one of several seed-transmitted fungal wheat diseases. Other diseases include loose smut, ergot, Fusarium head blight or scab and black point. Black chaff, a bacterial disease, also is seed-transmitted.



"By using a combination of seed treatments, clean seed and planting resistant varieties, seed-transmitted wheat diseases can be managed," he said.



Seed treatments can control seed-transmitted pathogens that may be surface-borne on the seed or internally seed-borne. Additionally, they can control soil-borne pathogens and insects and improve stand establishment.



"It is preferable to buy certified and treated seed or have it cleaned and treated by a commercial seed conditioner," Wegulo said. "If seed is treated on-farm, it is essential to clean it first before treating."



Cleaning seed before treatment is especially important if seed-transmitted diseases were present in the field during the growing season. For the seed treatment to be effective, ensure thorough, uniform coverage. If possible, use a broad spectrum systemic fungicide or fungicide-insecticide combination product.



Fungicide treatments are not effective against ergot and black chaff. The best strategy for managing these diseases is using certified, pathogen-free seed.



Resistant varieties can be used in combination with seed cleaning and seed treatments to more effectively manage seed-transmitted wheat diseases.



For more information about the wheat varieties grown in Nebraska and information on each variety, including disease resistance and susceptibility, visit the Wheat Varieties Virtual Tour Web site or the Nebraska Crop Improvement Association's online Seed Book.



For more information about seed treatment fungicides, consult UNL Extension NebFact NF03-587, Wheat Disease Fact Sheet No. 6: Management Program to Prevent Smut Diseases of Wheat. For more information about seed-transmitted diseases of wheat, consult UNL Extension Circular, EC97-1874, Diseases Affecting Grain and Seed Quality in Wheat. In addition to being online, both are available at local UNL Extension offices.



SOURCE: University of Nebraska news release.