Weed control in conservation tillage

CONSERVATION tillage is being adopted faster than any other practice in the history of farming. Former Secretary of Agriculture John Block estimated that 95 percent of all cropland in the United States might be farmed with conservation tillage by the year 2010 ( 27 ). Other national leaders, such as Sylvan Wittwer, director emeritus of the Michigan Agricultural Experiment Station, agree with Block on the importance of conservation tillage. In his speech at a 1983 symposium on agriculture in the 21st century, Wittwer said that conservation till-age was becoming increasingly important and was the most significant technology yet developed for producing crops while simultaneously controlling soil erosion. He projected use of conservation tillage at 200 million acres by the year 2000. Conservation tillage and weed control intimately linked. Acceptance of conservation tillage by producers depends upon the availability of herbicides that provide suitable weed control. A 1983 survey ( 1 ) showed that 58 percent of the producers included in the study did not intend to increase conservation tillage efforts because of inadequate weed control (48 percent of the farmers), reduced yields (21 percent), and excessive crop residues (15 percent). The three most important reasons farmers gave for opposing conservation tillage were inadequate …