Saffron Agronomy and Technology

Abstract To investigate the effects of mycorrhizal inoculation and humic acid application on the growth of

daughter corms of saffron (Crocus sativus L.) under two irrigation regimes, an experiment was conducted during the 2016–2017 growing season at the Research Farm of the Faculty of Agriculture, Sarayan, University of Birjand. The experiment was arranged as a split-split plot based on a randomized complete block design with three replications. Irrigation interval (20 and 40 days) was assigned to main plots, humic acid application (0 and 5 kg ha⁻¹) to subplots, and mycorrhizal inoculation (Glomus mosseae, G. intraradices, and non-inoculated control) to sub-subplots. Irrigation regime significantly affected total leaf weight, scale weight, and the number of daughter corms in different weight classes; humic acid influenced total daughter corm number, scale weight, corm weight, and daughter corm distribution across weight classes; and mycorrhizal inoculation impacted total daughter corm weight per plant, number of flower buds per corm, scale weight, and daughter corm counts in various weight categories. The highest leaf weight and dry stigma yield (1.7 g.m2) were obtained under 20-day irrigation intervals with G. mosseae inoculation and humic acid application, whereas the lowest values occurred under 40-day intervals without inoculation or humic acid. The maximum number of daughter corms (5.61 per plant) and flower buds (14.6 per corm) were recorded under combined G. mosseae inoculation and humic acid at 20-day irrigation. Daughter corms were predominantly distributed in the <4 g weight class across treatments, with the highest number of large corms (8–12 g) observed under 20-day irrigation with humic acid and G. mossea, although the highest number of small corms was also recorded in the above treatment. Overall, humic acid application and mycorrhizal inoculation relatively enhanced leaf weight, dry stigma yield, and daughter corm weight and number under the 20-day irrigation regime.

Abstract Although saffron (Crocus sativus L.), as one of the most important medicinal-spice species with low water requirement and high economic value, is not tolerant to salinity, evidences show that it is not highly sensitive to salinity either; however, information about saffron response to salinity at the field scale is very limited. The present study aimed to investigate the effect of irrigation with different levels of electrical conductivity (2, 5, 8, and 11 dS m-1) and different amounts of nitrogen (0, 25, 50, and 100 kg ha-1) on saffron stigma yield and changes in soil salinity. The results showed that stigma yield decreased significantly with increasing salinity in both years, especially in the second year; so that in the second year, no plants grew in the 11 dS m-1 treatment. The reduction in yield due to the highest salinity level in the first and second years was 75.3% and 80.9%, respectively. Only in the second year did nitrogen have a significant effect on stigma yield; the highest yield was obtained at salinities of 2 and 5 dS m-1 from the 50 kg N ha-1 treatment and at salinity of 8 dS m-1 from the 25 kg N ha-1 treatment. The effect of saline irrigation on the electrical conductivity of the saturated soil extract (ECe) was observed from 50 days after planting (DAP), and over time up to 150 DAP, water salinity treatments (except 2 dS m-1) led to an increase in ECe at two depths of 0 to 30 and 30 to 60 cm. At this time, the average ECe of the two depths in irrigation water treatments with salinities of 2, 5, 8 and 11 dS m-1 was equal to 0.3, 1.8, 10.9 and 13.9 dS m-1, respectively. In the second year, the treatments maintained the differences made in the first year relatively evenly throughout the growing season. Given the good regression relationship between the EM38 and ECe readings, the apparent salinity (ECa) could be estimated using the EM38. The differences between ECa in nitrogen and salinity treatments were very pronounced, with the highest ECa being obtained from the 11 dS m-1 treatment. Overall, the results showed that semi-saline water could be used for saffron cultivation with a slight yield reduction, however, irrigation and nutrition management should be carefully observed. In low salinity, 50 kg N ha-1 and in medium salinity, 25 kg N ha-1 is suitable for improving saffron yield. By observing the appropriate leaching fraction for saline conditions and the stability of soil salinity, it is expected that soil salinity at the end of the growing season will be 1.4 times the average of irrigation water, and soil salinity at the end of the saffron growing season will be between 0.94 and 1.44 times that at the beginning of the season.

Abstract To evaluate the efficacy of various doses of Haloxyfop-R-methyl herbicide, both with and without adjuvants, on the yield components of saffron (Crocus sativus L.), a factorial experiment was conducted in the Sarayan region during the 2023 growing seasons. The study was implemented using a randomized complete block design (RCBD) with three replications in a four-year-old saffron field. Treatments consisted of four herbicide doses (0, 54, 81, and 108 g a.i. ha⁻¹, representing the weedy control, 50%, 75%, and 100% of the recommended dose, respectively) and three adjuvant levels (no adjuvant, Citogate, and corn oil at 0.5% v/v). Herbicide applications were performed in February 2023, and yield characteristics, including flower number, fresh and dry flower weight, and dry stigma weight, were determined at the end of the harvest period in early December 2023. Results revealed that the highest flower number occurred in the hand-weeding treatment (a 77.76% increase compared to the weedy control), which did not differ significantly from the 100% and 75% recommended doses applied with Citogate (77.43% and 69.21% increases, respectively). The application of 75% and 100% of the recommended herbicide doses combined with Citogate resulted in fresh flower weight increases of 59.09% and 60.32%, respectively, exhibiting a performance comparable to the hand-weeding treatment (62.25%). While no significant differences were observed between adjuvant levels at the 0 and 50% herbicide doses, Citogate significantly enhanced the aforementioned traits at the 75% and 100% dose levels. Furthermore, the weedy control resulted in a 32% reduction in fresh flower weight compared to the weed-free check. The interaction between herbicide dose and adjuvant showed that the addition of corn oil increased dry stigma weight by 4.66%, 2.82%, 6.11%, and 2.98% at the 0, 50%, 75%, and 100% dose levels, respectively, relative to the no-adjuvant control. In comparison, Citogate supplementation led to more pronounced increases of 8.27%, 9.65%, 45.97%, and 43.22%, respectively. Consequently, adjuvant application significantly improved saffron dry stigma weight, with Citogate exhibiting a superior effect over corn oil. The maximum dry stigma weight was recorded in the hand-weeding treatment (94.51% higher than the weedy control), showing no statistically significant difference from the 100% and 75% recommended doses combined with Citogate (93.04% and 80.72% increases, respectively). In contrast, the weedy control led to a 35.20% reduction in dry stigma weight, significantly differing from all other treatments. Overall, the findings suggest that integrating adjuvants, particularly Cytogate, with Haloxyfop-R-methyl can effectively optimize saffron stigma yield.

Abstract The transition from raw material export to creating sustainable added value in strategic agricultural products is a cornerstone of economic resilience in developing countries. In the Iranian saffron industry, despite commanding over 90% of global production, a disproportionate share of the final value added accrues to international intermediaries. Previous studies have predominantly adopted a unidimensional or purely statistical approach to this challenge, failing to elucidate the hierarchical structure and causal relationships among the underlying barriers. To bridge this gap, this study aims to design a structural model of barriers preventing Iran from upgrading its position within the global saffron value chain. Utilizing the Interpretive Structural Modeling (ISM) approach and MICMAC analysis, insights from 12 experts from industry and academia were synthesized. The findings reveal a five-level hierarchical structure among the nine identified barriers. Contrary to common perception, ‘weak branding’ and ‘market fraud’ are not the root causes but rather the ultimate effects (‘dependent variables’) residing at Level 1 of the model. Conversely, ‘challenges in currency transfer’ and ‘instability of export regulations’ emerged with the highest driving power as the most fundamental barriers (Level 5, the roots). MICMAC analysis corroborated that these factors belong to the ‘independent/driving’ cluster, while variables like ‘exchange rate volatility’ and ‘saffron bulb smuggling’ act as key intermediaries, transmitting their effects up the hierarchy. The study concludes that any investment in branding will lack sustained effectiveness without first addressing these institutional and structural impediments (e.g., banking sanctions and unstable trade laws). The findings offer critical policy insights for strategic prioritization in the saffron sector.