AbstractThe evolution of concepts and definitions of agricultural systems over time is presented. Inputs of an agricultural system are classified as components and activities. A component is either a resource or a technology. The activities are the management of resources and the application of technology in the production process. The outputs of a production process will include both the targeted product and the environmental impact. When these terms are used to describe an agricultural system graphically, the dynamic aspects of the system can easily be illustrated and problems associated with the system can be properly identified. Sustainable agriculture is recognized as conveying certain objectives or delineating certain requirements of an agricultural system, in terms of both the input and output of the system. These objectives are: (1) producing necessary quantity of high quality food and fiber; (2) profitable to the grower; (3) conserving nonrenewable resources; and (4) harmonious with biological, physical and social environments. These objectives have long‐term implications and attempt to secure the future viability of agriculture. Therefore they embrace the concept of sustainability. The difficulty of constructing such a system is that not all the objectives are compatible; compromise or trade‐offs among the objectives are often necessary in developing a workable sustainable system. Progress and improvement can always be made through research, but no perfect system can realistically be constructed. General research issues in sustainable agriculture are discussed. Priorities in developing appropriate technology based on sound biological principles and laws of physics and mechanics for pest and weed control are sugges