Saffron Agronomy and Technology

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 This study aimed to explore the agronomic and economic implications of intercropping cumin and saffron in the Ghohestan region of South Khorasan province at a private research farm, under the supervision of the faculty of agriculture, University of Birjand, during the 2022-2023 period. To assess saffron's performance when intercropped with cumin, an experiment was set up based on a randomized complete block design with three replications in a uniform three-year-old saffron field. The experimental treatments involved different densities of cumin cultivation in the saffron field, including 0, 30, 60, and 120 plants per square meter (0, 25, 50, and 100% of its optimal density, respectively). The findings revealed that the LER index exceeded one in all treatment groups. The highest saffron stigma yield, recorded at 0.41 kg/ha, was achieved with an intercropping density of 60 cumin plants per square meter. The highest LER values were 1.94 and 1.92, obtained in the treatments with 30 and 60 cumin plants per square meter, respectively. Additionally, the Relative Value Total (RVT) was above one across all intercropping ratios. The greatest Intercropping Advantage index (IA), recorded at 0.074, was also achieved with the 60 plants per square meter cumin treatment. Consequently, increasing the cumin planting density in saffron fields, particularly at 60 plants per square meter, did not significantly affect saffron yield, leading to a recommendation for farmers in this region to adopt this practice for improved land use and economic benefit.

Abstract The storage conditions of saffron mother corms during the summer dormancy period, including natural and pseudo-dormancy stages, can probably affect the vegetative growth and the production of replacement corms (RC), which has not received enough attention in previous scientific studies. This experiment was carried out as a complete randomized block design with seven treatments and three replicates during the 2019 growing season in Qaen, Iran. Experimental treatments were three types of corm storage inside the soil [corm planting on 5th June (A) with natural soil temperature as control, A + summer irrigation on 5^th August, and A + mulch application obtained from wheat residues at the rate of 8 ton.ha^-1)] and four types of corm storage outside the soil [corm storage at room (ambient temperature) for three months started from 5^th June + corm planting on 5^th September (B), corm storage in constant temperature (25 ^oC and relative humidity of ~40 %) in incubator for three months + B, three months corm storage at variable temperature in incubator (one month in 20, 25 and 20 ^oC) + B and corm storage in room temperature (up to 5^th August) and incubator (up to 5^th September) + B. The studied traits were the length, number, and weight of leaves, the number and weight of the total RC, the weight of the main RC, the average weight of RCs, and the number and yield of RCs in different weight groups. The results showed that mulch application caused the highest length and number of leaves (35 cm and 9 No per plant, respectively). Incubation of corms at variable temperatures led to a significant increase in the total weight of RC. In contrast,  incubation at constant temperature had most significant effect on the number of RC (2022 corms per m²). The highest and the lowest mean weights of RC were obtained in the mulch application (7.23 g) and incubation at constant temperature (2.22 g), respectively. Plant residue treatment (mulch) decreased the number of small RC (less than 6 g) and increased the number of RC in the weight groups of 9-12 and 12-15 g. Incubation of mother corms at variable temperatures led to an increase in the number and yield of RC weighing more than 15 g. Overall, the treatments of plant residue consumption and storage of mother corms at incubator with variable temperatures, in which 66% and 61% of the RC yield was in groups weighing more than 9 g, respectively, were the best experimental treatments in terms of improving the growth of RC.

Abstract The combined effect of water and nutrient availability is one of the most important factors in corm growth and flowering of saffron. In addition, it seems that applying water in amounts more than conventional amounts in semi-arid areas can be more useful in saffron cultivation. Accordingly, the effects of irrigation regimes [two and four weeks intervals equal to application of 3600 (conventional irrigation treatment) and 7200 m³.ha^-1 (extensive-irrigation treatment) during saffron growth], as well as organic (30 ton.ha^-1 cow manure based on soil and manure analysis results) and chemical fertilizers (220, 150 and 100 kg.ha^-1 urea, super-phosphate and potassium sulfate, respectively) with a control treatment (no-fertilizer) are studied on some physiological growth indices, corm production and flowering of saffron in this experiment. The experiment was conducted as factorial based on a randomized completely block design with three replications in Sarayan county, Iran, during 2014-2016. Vegetative growth indices were studied during the first growth cycle, while flowering indices were measured during the second growth season. Total biomass has an increasing trend during saffron growth cycle in all treatments. This index was higher in cow manure treatment in both levels of water availability, during the last two growth months. Crop growth rate (CGR) was slow (below 3.9 g.m^-2.day^-1), rapid (3.9-12 g.m^-2.day^-1) and intermediate (5.5 g.m^-2.day^-1) in the early (the first 90 days of growth), middle (90-150 days after growth) and late (150-180 days of growth) growth periods. The highest CGR (12 g.m^-2.day^-1) was obtained in cow manure treatment and 145 days after the first autumnal irrigation. In all treatments, leaf weight ratio (leaf to total plant weight ratio) has a decreasing trend from two months after the first irrigation until the end of the growth cycle and it is slightly higher in fertilization treatments. Cow manure application increased the corm production and total corms weight per plant by 15 and 13%, respectively, compared with the control treatment. The highest mean weight of replacement corms (6.4 g) was shown in combined treatment of cow manure and two weeks' irrigation intervals. The highest values of flower number (98 flower per m²), flower yield (24.3 g.m^-2), style yield (0.56 g.m^-2) and dry petal yield (3.7 g.m^-2) were obtained in plants that had been treated with cow manure and received water in intervals of 4 weeks. In cow manure fertilizer and control treatments, the highest flower and stigma yield were obtained in irrigation intervals of 4 weeks, while in chemical fertilizer treatment, the highest flower and stigma yield were obtained in 2 week irrigation intervals. Therefore, it seems that application of cow manure combined with consumption of 3600 m³.ha^-1 is suitable during the first growth cycle of saffron during which corm density and transpiration area are low.