Saffron Agronomy and Technology

Abstract Evaluating the allocation trend of photoassimilates during the saffron growing season can lead to the identification of the key periods of plant growth. It is possible to improve the growth of the corm and ultimately increase the flowering of saffron by applying agricultural management according to the growth period. In this research, the allocation of photoassimilates between different organs of saffron under the influence of the mother corm weight (less than 4, 4-8, and 8-12 g) and the integrated and time-scheduled application of inputs (low-input and high-input), were investigated in a factorial layout based on a randomized complete block design with three replications. The maximum root weight was gained around 20th January (70 days after the first autumn irrigation) and the maximum leaf weight was observed on 29th February, and then it decreased, but after this date, the growth rate of the corm increased and reached its maximum value in the last month of the growing season. In all treatments, most of the mother corm reserves were consumed in the first 100 days after the first autumn irrigation, which coincides with mid-January. The production of replacement corms and their total weight accelerated 140 days after the first autumn irrigation, and its maximum amount (655 No. and 4148 g.m^-2, respectively) was obtained at the end of the growing season in the conditions of planting of big corms + high-input system. The highest mean weight of replacement corms (7.8 g) at the end of the growing season was obtained through planting of large mother corms + low-input system, while by planting small mother corms, the high input system increased the mean replacement corm weight. In all treatments, the highest corm growth rate was observed in the last month of the growing season (approximately 170 days after the first autumn irrigation). The total plant weight was strongly influenced by the weight of the mother corms, with no significant differences observed between the two input application levels. The highest crop growth rate (CGR) occurred in the final month of plant growth, reaching a maximum of 74.3 g.m⁻² day⁻¹ under the combination of large corm planting and a high-input system. The plant's relative growth rate (RGR) increased during the time intervals of 100–140 and 180–200 days after the first autumn irrigation. There was no significant difference between the treatments in terms of the duration of the active period of corm filling, and it was about 45 days. At the end of the growing season, the highest and lowest levels of photoassimilate remobilization (reallocation) from leaves to replacement corms (1016 kg.ha⁻¹ and 220 kg.ha⁻¹, respectively) were observed with the planting of large corms combined with a high-input system and small corms combined with a high-input system. The maximum remobilization efficiency (56.2%) was achieved by planting 4–8 g mother corms and using the high-input system. According to the results of this study, the final month of saffron growth was identified as the most critical period for the corm growth rate.

Abstract Saffron, despite exhibiting relative resistance to drought stress, is known to experience reduced growth and yield under drought conditions due to its underdeveloped root system. This study aimed to investigate the potential of organic matter in mitigating the adverse effects of drought stress on saffron. A factorial experiment was conducted in a completely randomized design with three replications in the pot at the  University of Torbat Heydarieh in 2023-2024. Treatments included two levels of drought stress (non-stress (90% field capacity) and stress (50% field capacity)) and six levels of organic matter (a mixture of manure and leaf-soil in a 3:1 ratio) applied to the soil at rates of 0, 2. 5, 5, 10, 20, and 40%. The studied traits included leaf length, leaf weight, root weight, corm number, corm weight, water use efficiency, and the concentration and uptake of nitrogen, phosphorus, and potassium. Results showed that across all the OM treatments, drought stress had a negative impact on all growth traits. For instance, water deficit led to a 67% and 58% decrease in average corm weight and stigma DW compared to non-stress conditions, respectively. Nitrogen and potassium concentrations were higher under stress conditions across all organic matter levels, while phosphorus concentration was higher under non-stress conditions. The application of all organic matter levels increased the studied traits under both stress and non-stress conditions, with a more pronounced effect under stress. Under non-stress conditions, there was no significant difference between the 20% and 40% organic matter levels for the studied traits, while under drought stress, the highest values were obtained at the 40% organic matter level, with significant differences compared to other levels. The application of 40% organic matter increased the average corm weight from 13.2 g to 34.8 g under drought stress. At 0, 2. 5, 5, 10, and 20% organic matter levels, water use efficiency was significantly higher under non-stress conditions compared to water deficit, but at the 40% organic matter level, this index was significantly higher under drought stress (1. 82 kg.m-3) than under non-stress conditions (1. 48 kg.m-3). Overall, the results of this study indicated that the application of organic matter can significantly mitigate the negative effects of drought stress and lead to a significant increase in leaf and corm growth of saffron under these conditions. In pot or greenhouse planting, considering the economic efficiency, the application of 20% organic matter is recommended under drought stress conditions. For verification on a larger scale, this experiment needs to be evaluated for field conditions.

Abstract  The study was conducted in order to compare the yield of onion, flower, stigma, and some agricultural characteristics of the saffron plant as an alternative crop. This study was carried out as a complete randomized block design in 3 replications in three regions of Aliabad, Naqdeh, Qajlu, Miandoab, and Balanj, Urmia, and in each region, four ecotypes of Korqand, Hoz-sarakh, Jarf, and Shahnabad were cultivated evaluated for 5 years from September 2016. From the second year to the fifth year, flowers were harvested, and the agricultural traits of the ecotypes, including the number of flowers, fresh weight of flowers, dry weight of petals, stamens, and production stigma yield, were measured or recorded. In the sixth year, the yield and the number of corms produced were measured. The results showed that there was a significant difference between the ecotypes. The interaction effect of place in ecotype, year in ecotype, and year in place was also statistically significant. The highest yields of stigmas and flowers were produced in Aliabad Naqdeh region, and among the four saffron ecotypes cultivated, Korqand and Jarf ecotypes had the highest number and weight of flowers, the highest weight of stigmas, the number of corms and the weight of corms in all three regions, respectively. According to the results, the ecotypes of Korqand and Jarf ecotypes are recommended for cultivation in the central and southern parts of West Azerbaijan province.

Abstract Saffron Yield and flowering depend on several factors, including the size of the corms. The production of daughter corms and the yield of flowers depend on the size of the mother corms. Large corms produce more corms and flowers per unit surface. In this investigation, the effect of Aminoful and Fulzyme Plus-Sp fertilizers simultaneously on the size of the corms and the yield of stigmas were studied. This experiment was conducted in 2018- 2019 on a saffron farm in Farim city 65 kilometers away from Sari city, with an altitude of 818 meters above sea level in a factorial form based on a randomized complete block design with nine treatments and three replications. In this research, saffron corms were prepared from Torbat- Jam landrace. Study treatments included Aminoful biostimulant (0, 125 and 250 mL.L^-1) and Fulzyme Plus-SP biological fertilizer (0, 2.5 and 5 g.L^-1).  The results showed that the interaction effect of aminoful foliar and application of Fulzyme plus-SP biofertilizer on the fresh weight of the leaf was significant at p<0.01, although the effect of these treatments on the number of leaves, dry weight of leaf, fresh weight of the daughter corms, the diameter of the daughter corms, fresh weight of flower and petals were significant at p< 0.05. The maximum number of leaves, fresh weight of leavesand dry weight of leaveswere observed using Fulzyme Plus-SP biological fertilizer and Aminofol biostimulant (A2F2). Also, the highest fresh weight of daughter corms and diameter of daughter corms after usage of Fulzyme Plus-SP biofertilizer and biostimulant Aminoful (A2F1) 57.71% and 22.56% respectively increased compared to the control one. The maximum fresh weight of flowers and petals was discovered with the application of Fulzyme Plus-SP and biostimulant Aminofol (A2F1 biological fertilizers. Moreover, these biological fertilizers had a positive impact on the morphological characteristics of saffron leaves and corms, causing an increasing the photosynthetic organs and growth of daughter corms. Therefore, the using of these two compounds led to an increase in corms weighing more than 20 grams. Also, these fertilizers increased the flowers and stigmas of saffron by more than 30% compared to not using them in the next year by increasing the number and size of saffron corms.

Abstract Saffron is recognized as one of the important agricultural products in Iran, but in recent years, its yield production has significantly decreased by 3.42 kilograms per hectare. One of the factors contributing to this decrease is the time-consuming process of harvesting and separating the stigmas from the flowers, which requires approximately 180 to 204 minutes to process 2400 to 2700 flowers. Planting, maintenance, harvesting, and processing saffron stages are done manually, which not only adds value to the product but also raises concerns about microbial and fungal contamination. Various studies have been conducted to separate saffron stigmas from flowers, but so far, there has been no integration of these studies. In this study, different methods of stigma separation are classified into three stages: flower alignment methods before cutting (including human labor, robots, mechanical and airflow mechanisms), methods of cutting flower parts (including pulling out the stigmas, rotational force, and cutting blades), and stigma separation methods (including centrifugal force, friction coefficient, airflow, and porous surfaces). The review and comparison of various saffron stigma separation devices have shown that a combination of image processing techniques, optical sensors, optimized mechanical systems, and the application of airflow is the best method to achieve high precision and quality in stigma separation. These devices benefit from mechanical and suction mechanisms to more advanced systems such as image processing and optical sensors. High-precision image processing methods for identifying the cutting location and optical sensors for accurately detecting the color and shape of the stigmas can increase the speed and accuracy of separation. This combination, along with optimized mechanical systems and the use of airflow as a non-contact method to reduce damage to the stigmas, can help maintain the quality of the final product. This article will review the recent advancements reports by researchers in the field of saffron, particularly in the area of mechanized methods for separating stigmas from fresh saffron flowers. Furthermore, by comprehensively analyzing these methods, their strengths and weaknesses will be discussed, and suggestions for improving the mechanization of the stigma separation process from fresh flowers will be presented.

Abstract Given the global impact of climate change and the consequential water crisis in arid regions, there is an urgent need to guide agriculture, a pivotal economic infrastructure, towards crops that are both low water-consuming and climate-compatible. Saffron emerges as a plant showcasing ecological compatibility and productivity in Herat province, Afghanistan, and East Khorasan, Iran. Strengthening saffron cultivation and implementing effective growth strategies not only reinforces the region's economy but also contributes to environmental preservation, mitigating various adverse effects. As crops heavily rely on climate and water resources, the development of saffron cultivation requires careful planning based on a comprehensive assessment of production conditions and the region. Consequently, this research aims to present a strategic plan for the development of the saffron supply chain in Herat province, particularly in Qourian County, Afghanistan. The study employed the SWOT method to identify internal and external factors. Through interviews with experts and subsequent weighting, the most significant strengths, weaknesses, opportunities, and threats were identified. Following the identification of factors and sub-factors in the SWOT model, four strategies—SO (Strengths-Opportunities), ST (Strengths-Threats), WO (Weaknesses-Opportunities), and WT (Weaknesses-Threats)—were determined. Ultimately, in selecting the optimal strategy for saffron industry supply chain development in Herat Province, Qourian County was prioritized based on the level of importance. The results of the final weight analysis for each group of factors identified conservative strategies, such as "training farmers for proper cultivation and processing," "distribution of short-term and long-term loans for saffron farmers and processing, service, and export companies," as well as "organizing an international exhibition to promote Afghanistan's saffron product," as the most suitable strategies.