Weed Control Research: Past, Present, and Future

Abstract

HE new scientific discipline, weed control, is the product of T research. So long as man has grown crops for his own personal use, he has fought weeds, for nature favors community life for her plants. True there are examples of pure cultures of plants in nature; the white pine forests of the northwest, the buffalo grass prairies, wild rice in the northern lakes. But by and large, the areas now devoted to our major crops, wheat, corn, cotton and forage, were occupied by mixed plant populations and now they are in monoculture or in controlled plant populations and this nature abhors. Hence through the ages and even more today the farmer has been at war with weeds, the invaders of his crops. But now the mode of warfare is changed. At last man has devised tools for combatting weeds, commensurate with the tools he uses for mining and manufacture and travel; modern mechanical and chemical tools; and these, I repeat, are the products of research. Before I be accused of boasting I hasten to add that, as in all fields of research, many of the key discoveries in chemical weed control have come about by chance. When Bonnet, in the final years of the past century, observed that copper salts, applied to mixed plant populations, killed broad-leaved weeds without harming cereals, he was using Bordeaux spray to combat disease on his grape vines. Almost simultaneously and apparently by chance Schultz in Germany and Bolley in America found that strong salt and acid solutions would bring about this same result. The point I wish to make is that while these discoveries were apparently chance observations, they had to happen. The stage was set; Liebig had elaborated his chemical theory of the nutrition of plants and proposed that plants obtain their nitrogen from the air as ammonia; Lawes had controverted this claim; chemists, and farmers, and amateur naturalists around the world