Assessment of qualitative characteristics of saffron (Crocus sativus L.) under the influence of bio-fertilizer and iron nanoparticles in saline stress conditions.
In order to investigate the effect of levels of organic fertilizer, iron nanoparticles, and irrigation water salinity on the quantitative and qualitative characteristics of saffron, a factorial experiment (organic fertilizer and iron nanoparticles) was conducted in a randomized complete block design with three replications in farms in Torbat Heydariyeh County in 2019-2020. The composite analysis was carried out at the location of salinity. The organic fertilizer factor had four levels of zero, 500, 1000, and 1500 kilograms per hectare, and the iron nanoparticles factor had two levels of non-consumption and application of four liters per hectare. The study was conducted under two different salinity conditions of 29.2 and 49.4 deciSiemens per meter. The organic fertilizer (granulated bio-organic) was applied during the breaking stage (after the first irrigation in late September and when the field was plowed). Comparisons of the mean mutual effects of the three factors showed that under both salinity levels of 29.2 and 49.4 deciSiemens per meter, in the absence of organic fertilizer, the use of iron nanoparticles significantly increased the level of crocin; however, under different levels of organic fertilizer application and iron nanoparticles, the level of crocin decreased significantly. In such a way that under salinity of 49.4 deciSiemens per meter and application of 1000 kilograms per hectare of organic fertilizer, the use of iron decreased the amount of crocin to 29.2 grams per liter. The highest amount of safranal was obtained under salinity conditions of 49.4 deciSiemens per meter.
In treatments with the application of 500 and 1500 kilograms per hectare of organic fertilizer and iron nanoparticles, as well as in the absence of organic and iron nanoparticles, no significant effect was observed. Irrigation with a salinity of 49.4 deciSiemens per meter, except for the treatment with the application of 500 kilograms per hectare of organic fertilizer, led to a significant increase in the level of picrocrocin. At this salinity level, the application of 1000 kilograms per hectare of organic fertilizer increased the level of picrocrocin to 53.2 grams per liter. Overall, it seems that for higher yields, irrigation with less saline water is recommended. In case of irrigation with water with salinity more than 2.4 deciSiemens per meter, the use of iron fertilizer is suggested for mitigating the effects of salinity.
