LIGHT ATTENUATION COEFFICIENT AND PRODUCTIVITY IN ’VERNAL’ ALFALFA

Abstract

A field stand of ’Vernal’ alfalfa (Medicago sativa L.), cut three times during the growing season, was studied over two years. The attenuation coefficient for radiation of wavelength 300 nm to 400 nm, and the rate of dry matter accumulation, was greater in first growth than in both second and third growth. Percentage dry matter increment below ground was least during first growth.