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Foxtails (Green and Yellow)
Foxtails (green and Yellow) commonly infest all crops in North Dakota. Foxtails are most competitive when small grains are seeded late and soil temperatures are warm for foxtail germination and rapid growth. Fields regularly chisel plowed generally have more foxtails than moldboard plowed fields. Moldboard plowing buries the foxtail seed which prevents emergence and reduces viable seed for subsequent years.
Making a decision on whether to control foxtail in small grains is not always easy. Research from North Dakota State University and in Canada has shown that foxtail often will not decrease wheat and barley yields, however; heavy foxtail infestations can cause harvest problems (especially when straight combining) and can cause dockage when the grain is delivered to the elevator. Situations where cost of a herbicide treatment for foxtail control is not justified include:
1. When foxtail infestations are light -- less than 30 plants/sq ft.
2. When the foxtail emerges after the crop is in the 3 to 4 leaf stage. This is especially true for barley. Once the small grain is in the 3 to 4-leaf stage, it can usually out compete foxtail, and make a herbicide treatment unnecessary. However, if the foxtail population is heavy (100 plants/ft 2 or more) control is generally needed. Another complicating is moisture stress since weeds will generally cause greater yield losses under drought conditions. Foxtail emerging at the same time or before small grain is more competitive than foxtail emerging after small grain. Some options to consider for foxtail control are:
1. If the foxtail infestation is heavy, and just emerging with the crop, consider harrowing or rotary hoeing as soon as possible. Harrowing or rotary hoeing is not effective once foxtail has 2 to 3 leaves. Small grains can be harrowed or rotary hoed until the 3 to 4 leaf stage with little effect on yield.
2. If a harrow or rotary hoe are not an option, then consider a herbicide. Hoelon needs to be applied to small foxtail (1 to 3-leaf), therefore the decision to apply Hoelon needs to be made early in the season. If wild oats are not present, then Stampede CM can be considered.
3. If the foxtail infestation is light to moderate, then it may be to wait and see if the crop will be able to out compete foxtail. If foxtail is still a problem by the time the small grain is in the 5 to 6-leaf stages, herbicides can still be used for control.
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