Evaluation of radiation use efficiency of intercropping of bean (Phaseolus vulgaris L.) and herb sweet basil (Ocimum basilicum L.)

In order to study radiation use efficiency and radiation interception in intercropping of herb sweet basil (Ocimum basilicum L.) and common bean (Phaseolus vulgaris L.), an experiment was conducted at the Agricultural Research Station, Ferdowsi University of Mashhad, Iran during growing season of 2008. Treatments were 1) sole crop of bean, 2) sole crop of sweet basil, 3) strip intercropping of bean and sweet basil (four rows bean and two rows sweet basil), 4) strip intercropping of bean and sweet basil (two rows sweet basil and four rows bean), 5) row intercropping of bean and sweet basil. Sweet basil was harvested at two times during the course of experiment. For this purpose a complete randomized block design with three replications was used. Results showed that in intercrop the fraction of intercepted radiation (F) was higher than the sole crop F. radiation use efficiency (RUE) of sweet basil in intercrop treatments was increased compared to sole crop and highest RUE of sweet basil obtained in secondary harvest of row intercropping (3.4 g.MJ-1), and the highest RUE of bean obtained in row intercrop too (2.4 g.MJ-1). Light extinction coefficient of bean was obtained as 0.55 and sweet basil 0.47, respectively. The highest Leaf area index (LAI) in bean was obtained in sole crop (4.3) and the highest LAI in sweet basil in first harvest was in strip intercropping with 4 rows sweet basil (3.2) and secondary harvest was in sole crop sweet basil (2.5).