evaluation of radiation interception and use by maize and bean intercropping canopy

intercropping is one of the management methods for crop production and leads to improvement of resource absorption and use by plants. based on this purpose the present field study was conducted to evaluate radiation absorption and uses efficiency in corn and bean strip intercropping at the farm of the faculty of agriculture, ferdowsi university of mashhad, iran during 2009. the experiment was set up in completely randomized block with three replications. the experiment constituted 6 treatments: sole crops of maize and bean, maize/bean strip intercropping of 2, 3, 4 and 5 rows of maize and bean plants. this experiment was conducted in the low input production system. each plot was 4×7.5 m in which within each plot the experimental treatments were based on replacement design. results indicated that leaf area index, light absorption, total dry matter and radiation use efficiency of maize and bean increased in all intercropping treatments in comparison with sole cropping. increasing of width of strip in the intercropping treatments in comparison with strip of 2 rows, with the exception of the radiation use efficiency (14.5% and 8.3%), lead to decreased leaf area index (34.2% and 5.5%), light absorption (20.5% and 11.2%) and total dry matter (1.5% and 13.1%) in maize and bean, respectively. with increasing width of strip, all of the measured traits decreased more in the central rows than the side rows. in both side rows and the central rows intercropping complementary effects was more on maize than bean in the measured traits. average of maize and bean radiation use efficiency was from 1.65 & 0.98 in the sole cropping to 1.94 & 1.15 gmj-1 in the strip of 2 rows, respectively.