The effect of intercropping of replacement and additive series on yield, light use efficiency, and radiation absorption in safflower and chickpea in Ilam

In order to study the effect of intercropping (additive and replacement series) on yield and radiation use efficiency of safflower and chickpea, a field experiment was conducted based on a randomized complete block design with three replications and nine treatments at the research farm, Faculty of Agriculture, Ilam University during the growing season in 2020. Experimental treatments were include: sole crops: safflower (S) (25 plants.m-2) and chickpea (Ch) (25 plants.m-2), intercropping of replacement series: (70% S, 30% Ch), (50% S, 50% Ch), (30% S, 70% Ch) and intercropping of additive series: (100% S+ 30% Ch), (100%S + 50% Ch), (100% Ch + 30% S) and (100% Ch + 50% S). The results showed that the highest grain yield (190 kg.ha-1) and biological yield (1070 kg.ha-1) of safflower were obtained in additive series 100% S+ 30% Ch. The highest (1.47) and the lowest (0.86) land equivalent ratio was obtained from additive series 30% S+ 100% Ch and replacement series of 30%S+ 70% Ch, respectively. The highest radiation use efficiency (RUE) of safflower and chickpea was obtained in the treatments of 100% S + 30% Ch and 50% S + 50%Ch, respectively. The highest radiation absorbed (603 MJ.m-2) was obtained in the treatments of 100% S+ 50% Ch. Intercropping patterns of chickpea and safflower improved the radiation absorption and radiation use efficiency and increased the total yield per unit area and LER.