Interception of photosynthetically active radiation and radiation-use efficiency of wheat, field pea and mustard in a semi-arid environment

Abstract

Fractional ground cover, fractional PAR interception (f), canopy extinction coefficient (k) and radiation-use efficiency (RUE) for wheat, pea and mustard were examined in a field experiment conducted over 5 years in a semi-arid environment in Australia. Two crop sequences were compared: fallow-wheat-pea and mustard-wheat-pea. Significant periods of water stress occurred in some years. Complete ground cover was not achieved and f ranged to maxima of 0.77, 0.80 and 0.80 in wheat, pea and mustard, respectively. For wheat, fallow increased f under both average growing season and drought conditions, but pea PAR interception was not influenced by crop sequence. Estimates of k for wheat, pea and mu..