I. Historical aspects, benefits and disadvantages of herbicide use During thousands of years up to about a hundred years ago, man expended most of required energy in arable farming with mechanical operations aiming to remove weeds and providing suitable conditions for the efficient growth of crop plants, considering that weeds compete with beneficial and desired vegetation, which means that weeds are plants growing where man does not which them to grow. With the dawn of industrialization, labor to the factories decreased manpower on the farms, which forced to think of more efficient mechanical means of weed control. The need of weed management is as old as agriculture itself. Six stages in the evolution of weed control practices can be considered: 1) 10,000 B.C.— removing weeds by hand; 2) 6,000 B.C.— the use of primitive hand tools to till the land and destroy weeds; 3) 1,000 B.C.— animal-powered implements like harrows; 4) 1920 A.D.— mechanically-powered implements like cultivators, blades, harrows, finger-weeders, rotary-hoes, rod-weeders, etc.; 5) 1930 A.D.— biological control and; 6) 1947 A.D.— chemical control, with the commercial development of organic herbicides such as 2,4-D and MCPA (Hay, 1974). Especially in the last century, for various reasons among which the population explosion, in his effort to produce adequate supplies of food, man needed to combat efficiently the attacks of various pests on agricultural and horticultural crops. Pesticides, falling into three major classes: insecticides, fungicides, and herbicides (or weed killers), are required. Herbicides, specifically, are used for control of weeds. At the end of the twentieth century, with an estimated world population of 6 billion people, some 700 million were undernourished and 1.3 billion exist on an inadequate diet. In 2009 FAO says that 1.02 billion people are undernourished, corresponding to 15 percent of the estimated world population of 6.8 billion. Undoubtedly, the first problem of Humankind is the lack of food, which affects especially underdeveloped countries. So, the urgent need for much greater application of herbicides and other agrochemicals is essential to increase food supply. Crops can duplicate or increase even more at the expenses of the agrochemicals use.