Crop Development and Growth

Growth of crops, plants, or plant parts is defined as the irreversible increase in size, whereas development is the continuous change in plant form and function with characteristic transition phases. Growth is primarily associated with the capture and allocation of resources, whereas development is mostly related to non-resource environmental cues such as temperature, photoperiod, and light quality. We separate development and growth conceptually, but both types of processes are closely linked. Thermal time and variations of thermal time corrected to account for photoperiod and vernalization are useful to model crop phenological development. Crop development, in particular the time of flowering, is one of the most important traits for crop adaptation. Breeders, agronomists, and growers understand the importance of matching the pattern of phenological development to their particular environments and use a combination of genetic and agronomic tools to manipulate development. Crop growth depends on (i) the capacity of the canopy to capture CO2 and radiation and the capacity of the root system to capture water and nutrients from the soil, (ii) the efficiency of the crop to transform resources (water, nutrients, radiation, carbon dioxide) into dry matter, and (iii) the partitioning of dry matter among plant parts. Stresses such as water deficits or soil compaction reduce growth by reducing the amount of resources captured by the crop, by reducing the efficiency in the use of resources, or both.