Effect of saffron-mallow intercropping patterns in the third year on possible cooling of corms for climate change adaptation Soroor Khorramdel 1 *, and Vida Varnaseri 2 1- Associate Professor, Department of Agrotecnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran 2- PhD student in Agroecology, Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Zabol, Iran *- Corresponding Author Email: khorramdel@um.ac.ir Introduction Saffron (Crocus sativus L.) a member of the Iridaceae family, called red gold, is the costliest spice in the world (Koocheki & Khajeh-Hosseini, 2020). Saffron is a fall-flowering geophyte plant and grass-like leaves that seem on or shortly after flowering. It has an important role in agricultural economy, especially in semi- arid regions (Koocheki et al., 2016; Koocheki & Khajeh-Hosseini, 2020). Intercropping has been an important production system in all regions for many hundreds of years (Vandermeer, 1989). Proper implementation of intercropping, especially in medicinal and aromatic plants, helps to cover soil and avoid loss of water and nutrients (Weisany et al., 2016). Therefore, it seems that in saffron intercropping systems, companion crops’ residues can effectively decline the adverse effects of high temperatures on dormant replacement corms. Therefore the current study was aimed to evaluate the effects of saffron and mallow intercropping flower and corm yield and quality of saffron. Materials and methods This experiment was conducted based on a randomized complete block design with three replications at Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad during 2015-2016, 2016-2017 and 2017-2018 growing seasons. Treatments were 15, 30, 45 and 60-cm row spacings for saffron from mallow planting rows and sole saffron and mallow cultivations. The experimental field was prepared according to the local practice for saffron and cumin production and then plots were established. Saffron mother corms were planted using basin method on 5 th of Sep. 2012. Mallow seeds were sown in the first growing seasons on 1 st of May 2015. In the third year, picking began on 9 th of October and finished on 9 th of November. In the year, flower number and dried stigma yield were recorded. Stigmas were dried in an oven at 30°C for 24 h to a constant weight before weighing (Gresta et al., 2009). Crocin, picrocrocin and safranal were measured based on ISO3632 trade standard. They are expressed as direct reading of the absorbance of 1% aqueous solution of dried saffron at 440, 257 and 330 nm, respectively (Lage and Cantrell, 2009). All the measured and derived data were subjected to the analysis of variance carried out by least significant difference (LSD) test (P≤0.05) using SAS 9.1 software. Results and discussion The effect of row spacings for saffron from mallow planting was significant on fresh flower yield, flower number and dried stigma yield of saffron. The maximum fresh flower yield, flower number, stigma yield and dry weight of daughter corms of saffron were observed in its monoculture with 26.51 g.m -2 , 81 flowers.m -2 and 0.212 g.m -2 and 380.11 g.m -2 , respectively (Figure 1, 2, 3 and 4). In comparisons amongst intercropping treatments with mallow, the highest values for these criteria were recorded for 30-cm row spacings for saffron from mallow with 13.39 g.m -2 , 46 flowers.m -2 , 0.155 g.m -2 and 362.22 g.m -2 , respectively (Figure 1, 2, 3 and 4).