Effects of Plant Density and Supplementary Irrigation on Agronomic Traits, Leaf Chlorophyll Content and Light Interception at Canopy Base in Chickpea Cultivars



To investigate the effect of plant density and supplemental irrigation on agronomic characteristics, chlorophyll content and light interception beneath the canopy of three chickpea genotypes under dryland conditions, an experiment was conducted at Research Station of Lorestan Agricultural Research Center located at Chegini, Khoramabad, during 2004-2005. The study was conducted using a split-split plot design with a randomized complete block layout, replicated four times. Dry farming (no supplemental irrigation (control)), dry farming supplemented with irrigation at 50% flowering, and dry farming supplemented with irrigation at pod filling period; three genotypes of Flip 93-93, Arman, and Gerit; and four planting densities of 30, 42, 54, 66 plants/m2 were taken as the main, sub, and sub-sub plots, respectively. The results revealed that on average of two supplemental irrigations led to increase of grain yield (556 kg/ha), biological yield (1102 kg/ha), plant pod number (6.8) and number of seeds per pod (2.52). All experimented factors significantly influenced the agronomic and physiological traits with the exception of cultivar × supplementary irrigation, and the three factor interaction. Cultivar Flip 93-93 as an early maturing genotype produced the highest grain yield and harvest index under all treatments. By increasing plant densities grain yield was increased, accordingly. The greatest grain yield of 1388 kg/ha and biological yield of 3823 kg/ha were obtained from the density of 66 plant/m2. Moreover, increasing plants per unit area resulted in an increment in leaf chlorophyll content accompanied by a reduction of interception under the canopy. The least light interception under the canopy was obtained by plant densities of 54 and 66 plants per m2. Supplementary irrigation at 50% flowering stage led to a significant increase of grain yield in all cultivars. Flip 92-93 was a superior genotype for grain yield.