ABSTRACT
The observation that insects, weeds, and plant pathogens reduce crop yield undoubtedly predates recorded history. The concept that yield is progressively reduced with increasing numbers of pests is widely known. Modern science and agriculture have long recorded and studied the deleterious impact of biotic stressors on yield. The recognition that pest infestations reduced yields prompted early agriculturists to select and breed plants that survived after infestation. Thus, the fundamental concepts of biotic stress and yield loss have been known and acted upon for millennia.
