Saffron Agronomy and Technology

Abstract Considering the impact of climatic parameters, particularly temperature and precipitation, on the growth, yield, and quality of saffron, this study aimed to investigate the flower and stigma yield along with some quantitative traits of saffron under the influence of climatic factors and agricultural management in ten counties of Khorasan Razavi Province (including Bajestan, Bakharz, Bardaskan, Gonabad, Quchan, Mashhad, Mahvalat, Taybad, Torbat-e Heydarieh, and Zaveh) through a questionnaire survey conducted over two years (2022 and 2023). The studied traits included time to flowering onset, flowering duration, flower yield, stigma yield, and stigma harvest index in saffron. Cluster analysis was performed to group cities. The results indicated that the simple effects of farm age, number of irrigations, summer irrigation, climate, year, and the interaction between climate and year were significant (p ≤ 0.05) for most flowering indices. The flowering duration ranged from 12.2 to 17.5 days in 2022 and from 8.2 to 12.1 days in 2023. The longest flowering duration in both years was recorded in Zaveh and Bakharz, while Bajestan had the shortest. The greatest and least reduction in flowering duration from the first to the second year were observed in Taybad and Zaveh, respectively. The flower yield ranged from 278.5 to 799.95 kg.ha^-1 in 2022 and from 152.1 to 360.8 kg.ha^-1 in 2023; in both years, Taybad and Bardaskan had the highest and lowest yields, respectively. The reduction in flower yield from the first to the second year ranged from 34% to 67%, with Zaveh and Bajestan showing the highest and lowest reductions, respectively. Correlation analysis between climatic parameters and saffron yield revealed a highly significant correlation between yield and the average August temperature, as well as between yield and the total February. As the average August temperature increased, yield decreased; conversely, increased in February precipitation improved yield. Since replenishment of photosynthetic material occurs in daughter corms during winter, rainfall during the growing season is crucial. All flowering indices were higher in counties with cooler climates compared to those with warmer climates. Furthermore, the decline in flower and stigma yield in the second year was less pronounced in warmer counties due to lower cold damage. Overall, it is recommended to adopt ecological intensification strategies, such as soil shading during hot summers, planting large corms at high density per unit area, and reducing the exploitation period, to mitigate the effects of climate change.

Abstract The aim of this research was to investigate the quantitative and qualitative characteristics of saffron (Crocus sativus L.) under the influence of corm inoculation with beneficial microorganisms and vermicompost in a randomized complete block design with three replications during two agricultural years, 2019-2020 and 2020-2021, at the Research Farm of Urmia University, Iran. The involved factors included 1) control without using phosphorus chemical fertilizer and without corm inoculation, consumption of 100% of the recommended phosphorus chemical fertilizer based on soil test, and without inoculation, corm inoculation with Pseudomonas fluorescens, corm inoculation with Glomus etunicatum, vermicompost (10 t.ha^-1 at planting time), corm inoculation with P. fluorescens + G. etunicatum, corm inoculation with P. fluorescens + vermicompost, corm inoculation with G. etunicatum + vermicompost, and corm inoculation with P. fluorescens + G. etunicatum + vermicompost. Based on the results of this study, the combined treatment of vermicompost with Pseudomonas and mycorrhiza had a positive, significant effect on the quantitative and qualitative yields of saffron. In most of the studied traits, the highest values ​​were observed in the combined biofertilizer treatments, although this difference was not significant for some traits with the chemical phosphorus fertilizer. The highest fresh and dry weight of corms was observed in the combined treatment of vermicompost with Pseudomonas (6.3 and 1.8 kg.m^-2) and mycorrhiza treatment (5.89 and 1.71 kg.m^-2), and the highest yield of stigma fresh and dry weight was observed in the combined treatment of vermicompost with Pseudomonas (0.018 and 0.007 g.m^-2) and also mycorrhiza treatment (0.017 and 0.005 g.m^-2). The results showed that the fresh and dry yields of saffron style in biofertilizer treatments, and in the combination of biofertilizer with vermicompost, were significantly higher than those in the phosphorus chemical fertilizer and control treatments. The highest crocin content was obtained in the combined treatment of vermicompost with mycorrhiza (24.5%), mycorrhiza treatment (23.8%), and the combined treatment of vermicompost with Pseudomonas and mycorrhiza (23.7%), which showed an increase of 10.61, 7.98, and 7.59 percent compared to the control, respectively. The highest safranal concentration was observed in the vermicompost treatment (41%), although there was no significant difference compared with the combined treatment of vermicompost with mycorrhiza (37%) and phosphorus chemical fertilizer (39%). In addition, the use of biofertilizers and their combination increased the amount of picrocrocin in saffron stigma, so that there was no significant difference with phosphorus chemical fertilizer treatment. In general, the results indicate that feeding saffron vermicompost and inoculating it with microorganisms had a significant effect on saffron growth and yield. The use of these fertilizers is an acceptable approach to reduce the overuse of chemical fertilizers while maintaining yield.

Abstract One of the methods to improve production and control flowering in plants is the use of growth regulators such as gibberellic acid. In order to investigate the effect corm priming time of saffron with gibberellic acid (GA3), a factorial experiment was conducted in a randomized complete block design with three replications at the Agricultural Research Station,University of Tehran in 2023. Two planting times (late June, late September) and four levels of gibberellic acid (0, 100, 200, and 400 ppm) were considered as treatments in the form of corm priming. The evaluated traits were the number of buds, time to germination, number of flowers, time to flowering, bud-to-flower conversion ratio, dry weight of stigma, and quality traits of saffron stigma. The results showed that priming saffron corms with 100 ppm gibberellic acid in late June significantly (α=1%) increased the number of flowers, bud-to-flower conversion ratio, fresh and dry weight of stigma, crocin and safranal. However, corm priming in late September with 200 ppm gibberellic acid resulted in a significant increase (α=1%) in the number of buds, number of flowers, stigma length, fresh and dry weight of stigma, and a significant decrease (α=1%) in the time to flowering onset and germination, although in some traits they were in the same statistical group as the 400 ppm level. Overall, the results of this experiment showed that first, corm priming in late June with low levels of gibberellic acid is better, but, corm priming in late September with higher levels is beneficial. Secondly, corms priming in late June and at a level of 100 ppm of the hormone can increase the amount of crocin and safranal and yield traits, while priming corms in late September can reduce the time to flowering and time to germination And will improve flower and corm yield in the first year.

Abstract Water resources, as one of the most critical inputs in agricultural production, have faced increasing constraints in recent years due to climate change and unsustainable exploitation. This situation underscores the need to optimize cropping patterns and enhance water productivity. The objective of this study is to examine the effects of changes in irrigation methods and water-reduction scenarios on crop yield and net profit within the cropping pattern of the Hamadan–Bahar Plain, with particular emphasis on saffron, a strategic crop for strengthening agricultural resilience. During the 2023–2024 agricultural year, crop yield simulations were conducted under three irrigation methods (surface, sprinkler, and drip irrigation) combined with deficit irrigation scenarios of 5%, 8%, and 10%. The simulated yield results were subsequently incorporated as inputs into a Positive Mathematical Programming (PMP) model to assess the impacts of yield changes on total agricultural net profit. The findings indicate that crop yields varied significantly across the three irrigation methods, and under the 10% deficit irrigation scenario, most crops experienced noticeable yield reductions. Consequently, saffron was introduced into the cropping pattern due to its low water requirement and high economic potential. A comparative assessment of irrigation methods revealed that drip irrigation consistently outperformed surface and sprinkler systems across all scenarios, effectively compensating for yield losses and mitigating reductions in farm income. Economic results further demonstrated that expanding saffron cultivation, alongside the adoption of modern irrigation technologies, not only offset the profit losses associated with water scarcity but, in some scenarios, increased net agricultural income relative to the baseline condition. Therefore, integrating saffron cultivation development with drip irrigation systems can be recommended as a sustainable and economically viable strategy for water resource management and for enhancing the resilience of agriculture in the Hamadan–Bahar Plain.

Abstract To evaluate the allelopathic and antifungal effects of saffron (Crocus sativus L.) leaf and corm extracts on the germination and early growth of Peganum harmala and on the mycelial growth of Fusarium nygamai, three independent factorial experiments were conducted using a completely randomized design with three replications. The experiments were conducted in 2021 at the Seed Research Laboratory, Research Greenhouse, and Plant Disease Laboratory of the Faculty of Agriculture at the University of Birjand. In the first experiment (laboratory bioassay), treatments consisted of two saffron plant organs (leaf and corm) and seven extract concentrations (0, 0.0625, 0.125, 0.25, 0.5, 1, and 2% w.v^-1) applied to assess inhibitory effects on the germination parameters of wild rue seeds. The second experiment (greenhouse pot study) employed identical treatments to evaluate seedling emergence and growth characteristics. In the third experiment, the same treatment structure was used to investigate the inhibitory effects of extracts on the mycelial growth of F. nygamai. The results of the interaction between treatments under laboratory conditions showed that the lowest germination percentage, mean germination time, and allometric coefficient were obtained with the 2% concentration of corm extract. The lowest length of radicle and shoot, dry weight of shoot, and root were obtained from the 2% concentration of corm extract. In greenhouse conditions, the 2% corm extract and the 1 and 2% leaf extract treatments resulted in the lowest germination percentage, the longest mean germination time, the lowest germination rate coefficient, and the lowest allometric coefficient. Furthermore, the minimum shoot length, root length, shoot dry weight, and root fresh weight were obtained from the same treatments. The results of the antifungal test showed that the lowest colony diameter on the third and sixth days was observed with the 2% extract, which did not differ significantly from that of the 1% extract. On the ninth day, the lowest colony diameter was obtained from a concentration of 2% corm extract, which had no statistically significant difference with concentrations of 1 and 2% leaf extract. Finally, the results of these experiments showed that the effect of inhibiting germination and growth of wild rue in laboratory conditions was greater in saffron corm extract and in greenhouse conditions in leaf extract, and the antifungal effect of leaf extract was greater. Therefore, based on the results of this study and further research into the fungicidal and allotoxic effects of saffron organ extracts, it is possible to develop natural fungicides and herbicides.

Abstract Saffron is a spice produced from the dried stigmas of the flower Crocus sativus L and is the most expensive spice in the world. Therefore, this product is frequently subject to adulteration and mislabeling. In the local Iranian market, saffron is classified into three main types—Sargol, Negin, and Pushal—based on the cutting position of the stigma, and their quality characteristics and prices vary according to the type. Consequently, the identification of saffron types is of great importance from both qualitative and economic perspectives.

In the present study, the combination of Fourier Transform Mid-Infrared (FT-MIR) spectroscopy and chemometric methods was employed to classify different types of Iranian saffron. Various spectral preprocessing methods were applied to correct the spectral data, and Principal Component Analysis (PCA) was used as an unsupervised model, while Linear Discriminant Analysis (LDA) with linear and quadratic kernels was applied as a supervised classification model. The best result was achieved using SG + D2 + MSC preprocessing and the linear kernel of the LDA model, yielding a prediction accuracy of 88.88% for the classification of the three saffron types. The acceptable results obtained demonstrate the effectiveness of this method for the non-destructive identification of different types of Iranian saffron.