evaluation of radiation interception and use by fenugreek (trigonella foenum-graecum l.) and dill (anethum graveolens l.) intercropping canopy

it is known that legumes give benefits to the soil such as improved nutrient availability, improved structure, reduced pest and disease incidence, and hormonal effects (wani et al., 1995). the major benefit of legume crops comes from biologically nitrogen fixation, deriving from the symbiosis involving leguminous plants and rhizobium bacteria (vance, 1998). based on this purpose, a field study was conducted to evaluate radiation absorption and use efficiency in fenugreek and dill in row intercropping as replacement series at the agricultural research station, ferdowsi university, ferdowsi university of mashhad, iran during growing season of 2013-2014. treatments included 20% fenugreek+ 80% dill, 40% fenugreek+ 60% dill, 60% fenugreek+ 40% dill, 80% fenugreek+ 20% dill and their monoculture. for statistical analysis, analysis of variance (anova) and duncan’s multiple range test (dmrt) were performed using sas version 9.3 (sas institute inc., cary, nc, usa). results indicated that leaf area index, light absorption, total dry matter accumulation and radiation use efficiency (rue) of fenugreek and dill increased in all intercropping ratios compared to monoculture. rue range for fenugreek was from 0.95 g.mj-1 in monoculture to 1.24 g.mj-1 in 40% fenugreek+ 60% dill. rue range for dill was from 0.64 g.mj-1 in monoculture to 1.02 g.mj-1 in 40% fenugreek+ 60% dill.