I conduct basic and applied research on beneficial plant-bacteria associations of agricultural importance, especially those involving the nitrogen-fixing bacterium, Rhizobium. A main focus is on the events leading to successful infection of clover roots by the Rhizobium trifolii symbiont, and the subsequent development of nitrogen-fixing root nodules. We also investigate a newly described natural association between Rhizobium and cereals (e.g., rice and wheat), and are exploring ways to increase cereal production under real-world agronomic conditions by exploiting the benefits of this plant-microbe association. A second research focus is the development of interactive computer software that combines the resolving power of microscopy and digital image analysis to study in situ microbial community ecology. Currently, model communities of pioneer root colonizing rhizobacteria and anaerobic bioreactors are being used for that work. This diversity of research topics exposes the student to many techniques that enable the individual to pursue research in the areas of plant microbiology, and microbial physiology/biochemistry/ecology.