Critical period for weed control: the concept and data analysis

Authors

Stevan Z. Knezevic, University of Nebraska-LincolnFollow
Sean P. Evans, University of Nebraska-Lincoln
Erin E. Blankenship, University of Nebraska-LincolnFollow
Rene C. Van Acker, University of Manitoba
John L. Lindquist, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2002

Comments

Published in Weed Science, 50:773–786, 2002. Copyright © Weed Science Society. Used by permission.

Abstract

The critical period for weed control (CPWC) is a period in the crop growth cycle during which weeds must be controlled to prevent yield losses. Knowing the CPWC is useful in making decisions on the need for and timing of weed control and in achieving efficient herbicide use from both biological and economic perspectives. An increase in the use of herbicide-tolerant crops, especially soybean resistant to glyphosate, has stimulated interest in the concept of CPWC. Recently, several studies examined this concept in glyphosate-resistant corn and soybean across the midwestern United States. However, these studies presented various methods for data analysis and reported CPWC on the basis of a variety of crop- or weed-related parameters. The objectives of this study are (1) to provide a review of the concept and studies of the CPWC, (2) to suggest a common method to standardize the process of data analysis, and (3) to invite additional discussions for further debate on the subject. Wide adoption of the suggested method of data analysis will allow easier comparison of the results among sites and between researchers.