Weeds have an important bearing on the extent and the character of the crop produced. An examination of any developing crop during the growing season brings the issue to the foreground. In the case of pasture land the efficiency is much reduced by allowing weeds to grow. One of us has found that more than 39 per cent of the pastures of Iowa contain the small ragweed (Ambrosia artemesiifolia) which not only prevents the growth of blue grass but also makes it difficult for cattle to graze. What has been specifically stated for pasture land is as pertinent to other crops in varying degrees.
Proceedings of the Iowa Academy of Science
©1922 Iowa Academy of Science, Inc.
Bakke, A. L. and Pammel, L. H.
"The Effect of Weeds upon Crop Production,"
Proceedings of the Iowa Academy of Science, 29(1), 271-279.
Available at: https://scholarworks.uni.edu/pias/vol29/iss1/60