Nutrients can be Effectively Absorbed by Saffron (Crocus sativus L.) Leaves and Affect Positively the Vegetative Growth and Flowering

Foliar application of nutrients (FAN) during the end of the saffron growing season, when the root absorption capacity is slightly reduced, can probably improve plant growth and yield. This study investigates the impact of various foliar nutrition treatments, including zinc, boron, copper, potassium phosphate, amino acids, and pure seaweed extract, alongside a control treatment of tap water (pH = ۷ and EC = ۰.۷ dS m⁻¹), on the nutrient absorption capacity of saffron leaves, as well as its vegetative and reproductive growth. All FAN treatments, especially amino acids, significantly increased leaf length and leaf width compared to the control treatment. Amino acid consumption delayed leaf senescence. Foliar application of all nutrients reduced the number of small replacement (daughter) corms (RC) in the weight group of ۱-۸ g (۳۳۹.۹ vs. ۴۸۶ corms per m۲, for FAN and control, respectively) while increasing their number in the group weight of ۸-۱۶ (۲۰۵.۵ vs. ۱۴۶.۰ corms per m۲) and more than ۱۶ g (۱۷.۲ vs. ۶.۶ corms per m۲). The potassium phosphate treatment demonstrated the highest yield of RC, surpassing the non-foliar nutrient application (control) by ۱۵.۵%. FAN treatments increased the mean weight and diameter of RC by ۱۶.۲% and ۲۳.۸%, respectively, compared to the control treatment. Amino acid spraying increased leaf (۵.۵۵ vs. ۲.۴۲%) and corm nitrogen content (۲.۲۵ vs. ۱.۴%) compared to the control treatment. Potassium phosphate has a significant effect on increasing the content of phosphorus and potassium in leaves and corms. The application of seaweed extract and boron increased the leaf boron content from ۲۷.۸ ppm in the control treatment to ۴۴ and ۷۶.۵ ppm, respectively, and the corm boron content from ۱۸ to ۴۰.۹ and ۶۹.۲ ppm, respectively. Foliar application of copper and zinc had a significant effect on increasing the concentration of these elements in saffron leaves and corms. All FAN treatments significantly increased the number of flowers, flower yield (۱۲۰.۰ and ۶۱.۹ g m-۲, for FAN and control, respectively), mean flower weight, and flower length compared to the control. Stigma yield with the application of amino acids, zinc, copper, potassium phosphate, boron, and seaweed extract was ۱۵۸.۵, ۱۴۱.۴, ۴۷.۱, ۱۸۰.۰, ۷۸.۵, and ۱۶۵.۷% more than the control treatment, respectively. The quality of the saffron stigma was not significantly affected by FAN treatments. In general, FAN, with the development of leaves as photosynthetic organs of the plant and increasing the content of nutrients in saffron leaves and corms, caused a significant increase in its flowering.

کلیدواژه ها:

Amino acid ، Boron ، Corm ، Micronutrients ، Stigma ، flowering ، Zinc