Plant Density and Competition

Abstract

Crops respond to planting density modifying the characteristics of individual plants by changing the number and size of their organs. The density response can be described mathematically by the ``Law of Reciprocal Yield''. Under very high density mortality of individuals occurs and is often more pronounced when environmental conditions are more suitable (e.g. high fertility). Yield-density curves can be asymptotic or parabolic, although the latter may reflect the existence of an additional limiting factor (e.g. water or nutrients). In general the spatial variability in planting density leads to yield losses which are higher when the yield-density response is a parabolic curve.