As the global population moves towards 10 billion people, record high temperatures are being set on an annual basis, while agricultural soils and water resources are experiencing serious attrition. Clearly the challenge of food security is ever more urgent. Increasing genetic gains of staple foods is a key part of the solution, since seed-embedded technologies are readily adopted by farmers. Improved breeding technologies facilitate the identification of complementary parents for hybridization and the selection of improved progeny. This chapter outlines a historical basis for plant selection and examines the areas in which sensor technology has evolved from our eyes to the application of proximal and remote sensing. The use of none-invasive methods are presented that can aid with selection of crop characteristics critical for improving yield potential, such as photosynthesis and partitioning-related traits, as well as the detection of traits that help protect yield, related to disease and lodging resistance.