Pattern of Absorption and Interception of Photosynthetically Active Radiation in Sesamum-Greengram Intercropping System

摘要

A 2 years study was conducted to analyze the pattern of interception and absorption of PAR (Photosynthetically Active Radiation) in sesamum-greengram intercrop in relation to growth, development and yield of the intercropping system. Nine treatment combinations with 4 replications were tested with sole crops of sesamum (cv. Rama) and greengram (2 greengram cultivars: cv. B-105 and WBM-4-34-1-1) with the rest representing the sesamum and greengram intercropping in 1:1, 2:1 and 4:1 ratio. The experiment was conducted at the Instructional Farm, BCKV, Jaguli W.B., India. The diurnal variation in absorption and interception of PAR by sesamum and greengram showed the peak at 11.30 h. Absorption of PAR in sole stand of sesamum was higher than intercropped sesamum when grown with greengram in 1:1 or 2:1 row ratios; however under 4:1 row ratio, sesamum absorbed maximum PAR among all the treatment combinations, the converse was recorded in case of greengram crop. The interception of PAR in sesamum canopy was maximum in 4:1 row ratio whereas the sole greengram intercepted more PAR than the intercropped one. The dry matter accumulation and yield in sesamum were highest in 4:1 row ratio whereas the sole greengram recorded the reverse. Dry matter accumulation in sesamum and greengram were significantly related to the absorption and interception of PAR. The interception of PAR during the early phase was proved to be single determining factor affecting the seed yields of both the crops.