Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



Weeds have been with man for countless years and it is evident that they will be with man for many more. As tillable land decreases and population increases, weeds will have to be controlled to insure the best land use. Weeds are controlled by cultural, biological and chemical methods. Cultural practices are most widely used and generally the most practical. Biological control is useful only in specific areas. Chemical control of weeds was not widely used method until the discovery of selective herbicides about 1900. A group of chemicals now receiving much attention are the herbicides commonly called “pre-emergence chemicals.” These chemicals are so named because of their time of application. The possibility of controlling annual weeds by pre-emergence applications of herbicides on large acreages of corn without the aid of cultivation has stimulated a large amount of interest. The objective of this study was to learn more about a relatively new group of herbicides used primarily as pre-emergence treatments in corn and how the control of annual weeds is influenced by the time and amount of rainfall that is received after the chemical is applied. These new chemicals are simazine and atrazine.

Library of Congress Subject Headings

Weeds -- Control


Includes bibliographical references




South Dakota State University