Using scabby wheat for cover crop

Wednesday, August 19, 2015

There have been several questions as to what the vomitoxin wheat could be used for. Several have suggested using it for cover crop. This is a way to get some use of the wheat, but it does not come without some risks according to the University of Nebraska specialists.

First, stand establishment will likely be poor because the Fusarium in the seed will infect the seedlings, reducing emergence or causing seedling blight after emergence. Second, some of the seed will not germinate at all due to Fusarium infection. The result will be in an uneven stand that cannot provide the full benefits of a cover crop. Another reason why scabby wheat should not be used may have long-term effects. Using the seed as a cover crop will introduce a high concentration of Fusarium inoculum in the field. When scabby grain comes in contact with moisture in the soil, the Fusarium spores germinate and form mycelium. Survival structures of the fungus, known as chlamydospores, form in the mycelium and remain in the soil for many years, providing inoculum that infects subsequent crops. Fusarium mycelium will infect seedlings of many field crops including corn, soybean and wheat, causing damping off and seedling blights. It also will infect the roots and crowns of plants that survive, causing root and crown rots. As a result, yield could be significantly reduced.

The potential rewards of using scabby wheat for cover crop (which are largely uncertain) are probably outweighed by the unknown risks. The best strategy may be to destroy highly scabby grain. The alternative is to clean it thoroughly and treat it with a systemic seed treatment fungicide before planting it as a cover crop. However due to the very high scab levels in some fields, most of the grain from those fields is so severely damaged that cleaning and treating it with a fungicide will not be effective and will certainly not economically justifiable.

Another alternative is to use scabby grain as feed for livestock. However, due to the high concentrations of vomitoxin in the grain, care must be taken to measure the levels of vomitoxin and ensure they are below the maximum advisory levels. before feeding.

A different topic -- I have retired from Extension and my last day in the office will be Aug. 20. I have enjoyed working with the many producers and other individuals in the area that I have served and will especially miss that interaction. As harvest approaches, I wish you the best of luck and have a safe harvest.