A shortage of effective, non-chemical pest control measures is a major constraint to more widespread adoption of sustainable agricultural practices. Overcoming this constraint with biological pest control tactics appears to be an attainable goal but will require substantial public sector support. Biological agents that are self-perpetuating do not offer profit incentive to private industry. On the other hand, microbial pesticides, which do require annual application, often are so highly specific for particular pests that the private sector is unable to risk venture capital for their development. Collaboration between public- and private-sector scientists is essential for biological pesticide development. In the U.S., a model working relationship for technology transfer between the private and public sector has been achieved with two commercial mycoherbicides, Collego™ and DeVine™. The model illustrates the strengths of the public sector for creating and storing fundamental knowledge of biological interactions at the organismal and ecosystem levels, also the capability of the private sector for large-scale production of fungi, for drying labile, living products, for effective patent protection, for satisfying EPA registration requirements, and for the commercial distribution, marketing and servicing of agricultural products. From three perspectives-biological, technical, and commercial—the success of Collego™ and DeVine™ has provided a definite step in the quest for low-cost weed control methods that are not hazardous to the environment nor in ground water. These successes also provide a model for an approach to reducing the dependence of agriculture upon chemical herbicides, the most extensively used chemical pesticides in agricultural production, likewise a useful insight toward technology that can lead to more widespread adoption of low-input, environmentally compatible and sustainable agricultural production.