What is in this article?:
- Annual losses from annual ryegrass in Northeast Texas run in the millions of dollars.
- Annual ryegrass populations (both resistant and susceptible) in cropland can be greatly reduced by using cultural and mechanical means in combination with chemical control techniques.
- For chemical control consider a two=step program.
TEXAS AGRILIFE Extension IPM specialist Jim Swart evaluates a wheat field for resistant annual ryegrass infestation.
Consider planting into a stale seedbed
Some local producers have been planting wheat in a stale seedbed with good success. They prepare the seedbed early in the fall and allow the ryegrass seed in the germination zone to emerge. Just prior to planting, they spray the field with glyphosate and then plant the wheat seed.
Spraying after planting but before the wheat has emerged is another option. This practice fits well into a resistant ryegrass management system—when the wheat is planted as late as possible to reduce ryegrass germination prior to the onset of cold weather. Leaving the soil undisturbed will minimize the movement of additional ryegrass seed into the germination zone. Local ryegrass populations are not as susceptible to glyphosate as they used to be, but it is still effective on seedling ryegrass.
Use row-placed phosphate fertilizer
Research has consistently shown that row-placed phosphate fertilizer is one of the best management practices for wheat, as well as other row crops. One pound of phosphate in the row is roughly equivalent to two pounds broadcast. This is one of the few inputs that can be reduced with no penalty in yield.
This practice is also advantageous in a resistant ryegrass management program. Row-placed phosphate is readily accessible to seedling wheat, and it enables the plants to rapidly gain a competitive advantage over seedling ryegrass emerging between the rows. Vigorous, well-nourished seedling wheat plants are very competitive with seedling ryegrass plants. This early advantage to wheat is critical, as ryegrass becomes more competitive as the growing season progresses.