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To develop saffron planting in Urmia, West Azerbaijan, Iran, a split-split plot experiment based on CRBD was carried out in the Urmia University's research farm for two years (2013-14). Nanofertilizers (Fe, P, K and nofertilizer (control)) as main plots, saffron ecotypes (Mashhad, Torbat-Heydarieh, Torbat-jam, Gonabad, Ghaen and Birjand) as subplots and maternal corm weight (6, 8, 10 and 12 g) as sub-sub plots were considered. Throughout the two years of the study, results showed significant differences between nanofertilizers levels, saffron ecotypes, maternal corm weight and their interactions in terms of all flowering traits. Results highlighted the importance of the nanofertilizers on improving saffron yield. In addition, it was also clear that Fe, P and K nanofertilizers all had positive effects on the saffron flowering. The results also illustrated that the high yield ecotypes Torbat-Heydarieh and Mashhad in Urmia region were due to similar climatic conditions of these regions. These results emphasized the importance of the mother corm weight on increasing saffron flowering was much better than both the nanofertilizer and saffron ecotype. As the mother corm weight increases from 6 to 12 grams, all the studied traits, including dry saffron yield and flower number also increased, by 5.17 times and 4.4 times, respectively. The results of stepwise regression and correlation coefficients noted that flower number, dry and fresh flower weight were the most effective traits on dry saffron yield. In total, it was concluded that saffron flowering traits are strongly influenced by environmental conditions and farm management. Therefore, the correct choice of saffron ecotypes, nanofertilizer and maternal corm weight are vital factors in farm management and economic saffron production.

The effects of mycorrhiza, Thiobacillus and Nitroxin (Azotobacter and Azospirillum sp.) biofertilizers under drought stress conditions with four levels of field capacity (FC) (control(100%), 85%, 70%, and 50%) on the antioxidant enzyme activities of medicinal pumpkin (Cucurbita pepo convar. pepo var. Styriaca) were evaluated during the years 2018–2019. Irrigation levels exhibited significant effects on all studied variables, except for the catalase (CAT) enzyme. A significant correlation was observed between the effects of irrigation levels and biofertilizers on antioxidant enzymes, soluble protein content, and grain yield. The highest activity of catalase and ascorbate peroxidase (APX) enzymes was achieved using mycorrhiza in 50% FC. Increasing drought intensity and mycorrhiza stimulated glutathione reductase (GR) and guaiacol peroxidase (GPX) activities by 32% and 66%, while Nitroxin increased them by 16% and 43%, respectively. Under severe drought stress conditions, only mycorrhiza exhibited a positive effect on GR and GPX enzymes. Under moderate and severe drought stress conditions, Nitroxin increased grain yield by 13% and 12.6%, respectively. The irrigation regimes and bio-fertilizers had a significant effect on β-sitosterol percentage. The highest amount was observed at the highest level of drought stress. Among the various bio-fertilizers treatments, the application of Thiobacillus yielded the highest percentage of β-sitosterol. The results of the present study demonstrate that the application of biofertilizers is beneficial in coping with drought stress.

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