Abstract

Of all the remote sensing techniques available for the study of crop condition, aerial photography has proved to be the most useful. Many of the environmental stresses that affect crops modify the morphology and physiology of individual plants so profoundly that the resultant changes in crop canopy reflectance can be recorded on an aerial photograph. The ability of aerial photography to record the adverse biological conditions of disease, pests, weeds and mismanagement, and the adverse physical and chemical conditions of drought, flood and problem soils are reviewed and illustrated using examples from the United Kingdom.