Interception of radiation and growth efficiency in field beans ( Vicia Faba L.)

Abstract

Measurements of intercepted radiation and dry matter were made in three crops of field beans. The extinction coefficient decreased with increasing leaf area index in each crop. Growth rates of 30 g m −2 d −1 were measured over 30 days in the first two sowings. This corresponded to a growth efficiency of 3.4% of incoming solar radiation and 4.1 g dry matter were formed for each MJ of absorbed photosynthetically active radiation. The growth efficiency over the growing period in these crops was 1.8% of incoming solar radiation. This is amongst the largest values recorded for an annual C 3 crop.