The Effects of Climatic and Agronomic Parameters on Flowering Indices of Saffron (Crocus sativus L.) in Khorasan Razavi Province
Pages 341-365
https://doi.org/10.22048/jsat.2026.566599.1583
Ramin Esmi, Soroor Khorramdel, Atefeh Mirzaeian
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.






