In a 1977 Question-and-Answer Session with Department of Agriculture employees, President Carter recalled the tremendous growth in peanut yields on his Georgia farm which resulted when they stopped plowing. He credited research that showed that more plowing meant less yield. It turns out that he was right: the plowing spread disease that lowered peanut yield. Herbicides made the reduction in plowing possible and improvements in herbicides have continued to benefit peanut farmers.

“Improvements in weed management are a contributing factor to advancements in peanut yield. …Cultivation was traditionally an integral component in peanut weed management. New herbicide developments improved overall weed control and cultivation is no longer needed. This directly addresses the susceptibility of peanut to infection by soil-inhabiting fungi. There is a direct correlation between incidence of stem rot and displaced soil thrown on peanut plants from cultivation. Not needing to cultivate lessens disease epidemics and protects peanut yield. In 2013, 21 herbicide active ingredients were registered in the U.S. for weed control in peanut. In contrast, there were 12 herbicide active ingredients registered for use on peanut in 1980. Recently developed herbicides are more consistent, versatile, and have a broader-spectrum than earlier herbicides. …There were no selective postemergence herbicides registered in 1980 that controlled emerged grasses. In  2013, there were three postemergence herbicides registered for use on peanut to control annual and perennial grasses…. Registrations of these herbicides were major weed control milestones in peanut production and have largely eliminated yield losses from grasses that escaped earlier control efforts.”

Author: Johnson, W. C.
Affiliation: USDA-ARS, Tifton GA
Title: Yield Advances in Peanut – Weed Control Effects
Source: 2013 Proceedings of the American Peanut Research and Education Society, Inc. http://apresinc.com/wp-content/uploads/2014/02/Volume-45-Proceedings_2013.pdf