LINCOLN, Neb. — When rainfall is lacking, livestock producers sometimes need to be creative on how to stretch their forage resources. One option might be to graze volunteer wheat fields while still being a “good neighbor” to nearby grain farmers who are protecting potential wheat grain yields for the upcoming growing season.
Generally, when wheat fields are hailed during the grain fill period, there is a high probability that volunteer wheat plants will grow from the shattered grain seeds. These volunteer plants can then provide “live green bridge” for feeding wheat curl mites, which may then vector the wheat streak mosaic disease into newly emerging wheat fields drilled in the fall.
The challenge for livestock producers is that some crop advisors recommend controlling volunteer wheat soon after harvest to break the green bridge. This concept can be misleading, since wheat curl mites can also survive on other wild grass species such as barnyardgrass, some foxtails and even later planted green corn fields. So, growers focusing only on killing volunteer wheat plants early or soon after harvest may be limiting supplemental forage growth for livestock feed while still not effectively controlling the curl mites.
To prevent neighborhood feuds over when to control volunteer wheat, the compromise is managing the wheat curl mites’ life cycle. Since curl mites cannot survive without a live plant food source for more than two weeks, the best strategy for protecting the next wheat production crop is to assure that all volunteer wheat, grassy weeds and late planted corn fields are dead (dry) (two weeks prior to wheat emergence) within a half mile of newly drilled wheat fields this fall.
Following this strategy, the volunteer can be used as an alternative forage for livestock producers. Then, neighbors can cooperatively time their herbicide applications and grassy weeds control to starve the wheat curl mites and not allow them to move from green field to neighboring green field.
Other best management practices for managing wheat streak mosaic include drilling wheat varieties with high resistance to mosaic disease, avoiding (early wheat planting) delaying drilling until after the Hessian fly free fall date, and following crop rotations.
— Todd Whitney, Extension Educator, University of Nebraska-Lincoln