The new scientific discipline, weed control, is the product of 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.