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 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 To evaluate the allelopathic and fungicidal effect of saffron leaf and corm aqueous extracts on the germination and growth characteristics of London rocket (Sisymbrium irio) and Fusarium solani, independent experiments were conducted as factorial arrangement based on the completely randomized design with four replications at the Faculty of Agriculture of Birjand University in 2022. Treatments to test the inhibitory effect of saffron extract on London rocket seed germination characteristics including two types of saffron organs (leaf and corm) and seven extract concentrations (0, 0.25, 0.5, 1, 1.5, 2, and 4 w/v %). Experimental treatments to investigate the inhibitory effect of saffron extract on the growth of Fusarium solani fungus including two types of saffron organs (leaf and corm) and seven extract concentrations (0, 1, 0.5, 25. 0, 0.125, 0.625, and 0.0312 w/v %). The results showed that the type of extract has an effect on the germination percentage, germination rate, mean germination time, length and fresh and dry weight of radicle, the length, fresh and dry weight of the plumule, seedling dry weight, and the seedling vigor of London rocket were significant, and the corm extract had more negative effects compared to the leaf extract. As the extract concentration increased, its inhibitory effect also increased. The extract concentration of 4% significantly reduced the radicle length and fresh and dry weight, the plumule length and fresh and dry weight, seedling dry weight, and seedling vigor of London rocket compared to the control. The results of the interaction showed that the lowest percentage of germination, germination rate, radicle length and fresh and dry weight, plumule fresh and dry weight and seedling dry weight of london rocket were observed at the concentration of 4 % corm extract. The results of the interaction effect of extract type and extract concentrations on Fusarium solani colony diameter showed that all the concentrations of corm extract inhibited the growth of Fusarium solani in all four stages of sampling. In leaf extract, concentrations of 0.125, 0.25, 0.5 and 1% completely inhibited the growth of Fusarium solani in all four stages of sampling. Finally, the results of these experiments showed that the effect of inhibiting the germination and growth of london rocket as well as the antifungal effect is greater in saffron corm extract than the leaf extract. Therefore, considering the results of this research and conducting more research in the field of allelopathic and fungicidal effects of saffron organ extracts, we can proceed to produce natural herbicides and fungicides.