Within the past 15 years weeds have come to be recognized as the cause of one of the most important losses suffered by American farmers. Experiment station and extension workers, farmers, weed commissioners, insurance companies and farm credit agencies, chambers of commerce and others either directly or indirectly dependent on agriculture have become aroused by the menace of an increased dissemination of noxious weeds.
In Iowa weeds cause a loss of many millions of dollars annually. They crowd out desirable crops, rob them of plant food and moisture, act as hosts for insects and disease-producing organisms of crops, poison or injure livestock, depreciate land values and cause extra labor in cultivation; thus they increase the cost of food production.
Sylwester, E. P. and Porter, R. H.
"Noxious and other bad weeds of Iowa,"
Bulletin P: Vol. 3
, Article 1.
Available at: http://lib.dr.iastate.edu/bulletinp/vol3/iss64/1