Private investment in plant breeding has been increasing while public plant breeding has stagnated or declined. Moreover, research investment among crop commodities is uneven. Using a comprehensive survey of U.S. plant breeders from 1994, we use a simultaneous equations model to examine incentives and public-private tradeoffs in plant breeding research among 84 crop commodities. Allocation of private breeders among crops is strongly influenced by market size, hybrid seed technology, and ease of breeding improvement. In general, the allocation of public breeders does not appear to “crowd out” private breeders, but some competition may occur in applied breeding. Public breeding declines as private breeding increases on a commodity. Public breeding is also affected by market size, ease of breeding improvement, and political influence.

Production functions to explain regional wheat yields have not been studied extensively in the Canadian prairies. The objective of this study is to employ a Just-Pope production function to examine the relationship between fertilizer inputs, soil quality, biodiversity indicators, cultivars qualifying for Plant Breeders' Rights (PBR), and climatic conditions on the mean and variance of spring wheat yields. Using regional-level wheat data from Manitoba, Canada, model results show nitrogen fertilizer, temporal diversity, and PBR wheat cultivars are associated with increased yield variance. Mean wheat yield is reduced by the proportion of land in wheat, the interaction of growing temperature and precipitation, and spatial diversity. By contrast, higher soil quality and PBR wheat cultivars increase mean yield. The wheat yield increases attributed to PBR range from 37.2 (1.4%) to 54.5 kg/ha (2.0%). Plant Breeders' Rights may have enhanced royalties from increased certified seed sales, but the benefits in terms of higher wheat yield or lower yield variability are limited. Future research is required to understand the interactive effects of fertilization practices, genetic diversity, and environmental conditions on regional wheat yield stability.