ABSTRACT

Ever since humans began to settle in one place and cultivate food crops, they have continually developed and improved methods to control weeds to protect crops. Weed control methods have evolved over time, beginning with hand weeding (10,000 B.C.), primitive hand tools (6,000 B.C.), animalpowered implements (1,000 B.C.), mechanically powered implements (1920), biological control (1930), and chemical weed control (1947) (Hay, 1974). The era of chemical weed control began in 1947 with the introduction of 2,4-D and MCPA [(4-chloro-2-methylphenoxy)acetic acid] herbicides (Hay, 1974). The development of safe, effective, and relatively inexpensive herbicides, coupled with advances in application technology during the past six decades, has provided many successful weed management options in crop production. Herbicides provide cost-effective and efficient control of weeds and have dominated other weed control methods in recent years.