Competition for light and its effect on leaf and spikelet development of wheat plants

Abstract

The effect of changes in the light environment of wheat plants at different stages in their growth was examined by growing single plants in tubes and changing the spacing of the tubes (population density) during development. Individual leaves on the main stem were reduced in both area and weight by transfer of the plants from high density to low density during the period from initiation of growth of the leaf on the apex to its appearance above the sheath. The number of fertile spikelets per ear was increased by transfer to low density in the period between formation of double ridges and ear emergence. It is suggested that the potential for grain yield of a wheat ear is affected by the light environment of the shoot at any stage before ear emergence.