Paraquat and the revolution in land preparation

Paraquat led to a revolution in land preparation that has had profound economic, social and agronomic effects around the world.

The herbicidal properties of paraquat were discovered by ICI (a legacy company of Syngenta) in 1955 and was introduced to world markets in 1962 under the brand name GRAMOXONE®. Paraquat quickly gained acceptance as a tool for controlling weeds in emerged row crops and tree crops. However, it was the realization that paraquat could replace time- and labor-intensive plowing, which in the 1960s and 1970s led to an expansion of research around the world on a scale unprecedented for a single agricultural chemical and to a revolution in farming.

A crop of corn or weeds?Why is paraquat such an unique product and why is it so valuable to farmers? Before we can answer that we have to consider the importance of weeds.

Weeds have existed as long as man has farmed. Weeds hinder planting a crop and once the crop has emerged they continue to compete for water, light, nutrients and space. Weeds need to be removed before planting and controlled thereafter.   There are several ways to control weeds:

Hand Weeding is hard, debilitating and tedious work. It can occupy the farmer and his family for many hours of the day.  In many parts of the world hand weeding is the most time-consuming human activity aside from sleeping.

Mechanical Weeding is faster than hand weeding, but consumes energy and can expose the soil to water and wind erosion.

The Plow was first used to prepare land for planting more than 2,000 years ago. It has remained a major weapon in weed control through its ability to bury growing weeds to depths from which they can not emerge. Hoes or machetes wielded by hand and later implements with the same function drawn by animal or tractor power are the traditional means of controlling weeds in growing crops.

The Advent of Herbicides represented an enormous advance. Although several inorganic chemicals were in use for weed control in the early 20th century, it was the introduction of the selective herbicides MCPA and 2,4-D in the 1940's that led to widespread use of chemicals for weed control and stimulated a great effort by the chemical industry to discover new herbicides.