Comparison of Foliar and Soil Application of Iron Nano-Chelate on Sunflower Growth Characteristics in a Saline Soil

Modern technologies, such as biotechnology and nanotechnology, play an important role in increasing production and improving the quality of food produced by farmers. Salinity also directly affects the absorption of nutrients elements. This study aims to investigate the use of nano-chelate with ethylene diamine tetra-acetic acid (EDTA) and Humic Acid (HA) base as fertilizer agents on Sunflower.

This study was done as a pot experiment as a factorial in a completely randomized design including two levels of iron nano-chelate fertilizer (ethylene diamine tetra-acetic acid and Humic Acid) and two methods of application of fertilizers (foliar application with the level of one gram per Liter and soil application with the level of one gram per kilogram with the control) in three replications in the research greenhouse of Zabol University. Five sunflower seeds were used for cultivation. The treatments were applied in two ways that are soil use and spraying form, when plants are 4 to 6 leaves the tratments have been used in 4 steps and at intervals of 15 days. The pots were irrigated by distilled water and weighting method during the experiment period. Some growth parameters, chlorophyll content as well as nutrients (Fe, Zn, P, K) of sunflower shoot (Helianthus annuus) under permanent salinity conditions were investigated about two months after planting. Statistical analysis was performed on the basis of SAS software and Analysis of data variance was done based on ANOVA software. The mean of measured indices was categorized using Duncan test at the level of 0.05.

Results showed that the interactions of fertilizer type and its method of use have a significant effect on the shoot indexes (dry weight, leaf number and plant height), leaf chlorophyll content (a, b, total and carotenoids) and nutrient concentration (Fe, Zn, P, K) of sunflower plant (p≤0.01). Comparison of the means showed that spraying EDTA-based iron nano-chelate increases dry weight of shoot, the number of leaves and plant height (1.15, 1.21 and 1.05 times, respectively), the level of leaf carotenoid (1.76 times) and also Fe concentration in the shoot (2.37 times) compared to the control. Moreover, in EDTA-based iron nano-chelate soil application, the concentration of phosphorus and potassium elements is respectively increased 1.59 and 1.94 than control.

According to the results, spraying EDTA-based iron nano-chelate improved most of the sunflower growth parameters, which shows the superiority of this Nano-fertilizer to HA-based iron Nano-chelate in saline soils.