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• 1. [Article] The influence on winter wheat yields of competitive weedy species

  A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. ...

  Citation × Citation Citation Abstract Copy Title: The influence on winter wheat yields of competitive weedy species Author: Albeke, William Edgar A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. The experiments were designed so that the effects of variety, nitrogen fertilization, and weed competition could be evaluated. The interactions between these factors were also studied. Ryegrass (Loolium app.) and downy brome (Bromus tectorum) were the two weed species studied. Under high winter rainfall and ryegrass competition yields of wheat were seriously impaired in both the short and tall growing wheat varieties tested. As rates of nitrogen increased yields of wheat did not increase where a medium or heavy stand of ryegrass was present. Yield of wheat was reduced under high nitrogen and high ryegrass competition. A response to 60 pounds of nitrogen per acre was noted where no ryegrass competition was present. One hundred twenty pounds of nitrogen did not increase yields appreciably, especially in the Gaines variety. In the two remaining experiments, response to nitrogen fertilization was not as prominent due to lack of moisture throughout the growing season. However, downy brome competition decreased yields at one location under all three fertility levels. At the other location a poor stand of downy brome and arid conditions accounted for the lack of competitive effects. No differences were noted in competing abilities of the tall vs. the short growing varieties. In general it was concluded that in order to get maximum response from nitrogen fertilization in wheat, weeds would have to be controlled. Title: The influence on winter wheat yields of competitive weedy species Author: Albeke, William Edgar A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. The experiments were designed so that the effects of variety, nitrogen fertilization, and weed competition could be evaluated. The interactions between these factors were also studied. Ryegrass (Loolium app.) and downy brome (Bromus tectorum) were the two weed species studied. Under high winter rainfall and ryegrass competition yields of wheat were seriously impaired in both the short and tall growing wheat varieties tested. As rates of nitrogen increased yields of wheat did not increase where a medium or heavy stand of ryegrass was present. Yield of wheat was reduced under high nitrogen and high ryegrass competition. A response to 60 pounds of nitrogen per acre was noted where no ryegrass competition was present. One hundred twenty pounds of nitrogen did not increase yields appreciably, especially in the Gaines variety. In the two remaining experiments, response to nitrogen fertilization was not as prominent due to lack of moisture throughout the growing season. However, downy brome competition decreased yields at one location under all three fertility levels. At the other location a poor stand of downy brome and arid conditions accounted for the lack of competitive effects. No differences were noted in competing abilities of the tall vs. the short growing varieties. In general it was concluded that in order to get maximum response from nitrogen fertilization in wheat, weeds would have to be controlled. Close