Professor Pitman is distinguished for his research on ion transport in plants, particularly relating the activity of the plant as a whole to mechanisms at the cellular and membrane levels. He was first to develop techniques to estimate ion fluxes in higher plant tissues. His work has led to explanations of the discrimination between sodium and potassium, to models for ion transport through the root to the shoot and to increased understanding of plants under salt or water stress. He played a leading role in introducing the Academy's "Web of Life" biology course to Australian schools.