Utah State University Extension
Water, nutrients, space, and sunlight are critical resources for the growth and development of all crops. Over the years, recommendations for inputs such as fertilizer, irrigation, and seeding rate have been fine-tuned to maximize yields while minimizing cost. Weeds compete with crops for this limited pool of resources. As resource availability shrinks, crop yields almost immediately begin to decline
Creech, Earl; Israelsen, Clark; Pace, Mike; and Whitesides, Ralph, "Herbicide Strategies to Maximize Yield in Glyphosate-Resistant Corn" (2012). All Current Publications. Paper 1324.