Evaluation of the effects of saffron–cumin intercropping on growth, quality and land equivalent ratio under semi-arid conditions

Abstract

Proper rows arrangement in an intercropping system is an important factor for reducing interference between plants and better absorption of environmental resources. Effects of saffron–cumin intercropping based on replacement series on growth, yield, quality and total land equivalent ratio (LERT) was studied as two-year field experiment based on a randomized complete blocks design arranged in factorial with three replicates at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during 2013–2014 and 2014–2015 growing seasons. Different planting densities of saffron (low, medium and high equal to 64, 128, 256 corms m−2, respectively) and saffron–cumin intercropping (in proportion of 100–0, 75–25, 50–50, 25–75 and 0–100) were considered as the first and the second experimental factors, respectively. Based on the results, interaction between saffron planting density and saffron–cumin ratio was significant on flower number and dried stigma yield. However, crocin, picrocrocin and safranal were not affected by saffron planting density and intercropping ratios or their interaction. In each intercropping ratio, flower number and dried stigma yield increased with increasing saffron planting density. In the first and second year, reduction in cumin ratio in intercropping decreased cumin grain and essential oil yields. Nonetheless, saffron–cumin intercropping could partly compensate yield loss. For instance, in the second year, cumin yield in 50% saffron+50% cumin treatment was found to be 23.33% less than cumin monoculture treatment. In both years of the experiment, the highest LERT was observed in 50% saffron+50% cumin treatment. Hence, this ratio along with high planting density of saffron (256 corms m−2) is recommended for saffron and cumin intercropping.