Climate is the variation in meteorological factors over a large area formed over many years. It determines plant
adaptation to a growing region. Weather on the other hand is the environmental condition described by the short term
variations in meteorological factors within a local area. It determines crop development and productivity.
Weather affects the choice of specific crop production activities (i.e., how the crop is produced in the field). Plant
breeders usually develop breeding programs to produce cultivars for specific production regions. Crop production
is subject to the vagaries of the weather. Unpredictable weather can drastically reduce crop yield. Crop varieties
used in regions that are prone to adverse weather during production need to have the capacity to resist or tolerate
environmental stresses to an extent that they produce acceptable economic yield. After completing this chapter, the
student should be able to