ABSTRACT
Herbicides can be given a major part of the credit for the large increases in crop yield over the last fifty years. The use of herbicides prevented the sharing of light, water and minerals with weeds and allowed the breeders to develop less competitive crops with higher harvest indices. The decreases in cultivation due to chemical weed control led to less soil erosion, less soil compaction and less evaporation of soil water. Malthus’s prediction of starvation due to populations expanding faster than possible increases in food supply has not materialized (but may materialize if humanity is foolhardy and does not control population growth). The reason Malthus did not prove to be right was agriculture’s wisely adapting and adopting herbicides with new breeding. Selective herbicides, those that control weeds with minimum effects on crops, have been the most instrumental group of agrochemicals in increasing yields.
