The effect of concomitant use of nano-structured essential metals and sulfur on growth characteristics of safflower

Abstract
Nutrient deficiencies of zinc, manganese, and iron are prevalent in calcareous soils of arid and semi-arid regions due to their reduced solubility under alkaline conditions. Sustainable crop production is crucial for the growing population. Sulfur fertilizers can enhance micronutrient availability by decreasing soil pH. This study investigates the influence of nano-chelated essential metals (Zn, Mn, Fe) and sulfur application (0 and 40 kg ha-1) on safflower growth in Maragheh, Iran. Both factors significantly affected phenological development and morphological traits. Results indicated that sulfur application notably improved morphological traits such as ground cover, stem diameter, plant height, and capitulum diameter. The highest seed yield was achieved with nano-chelated Zn application, and the best performance was linked to the combined application of sulfur and nano-chelated Zn.

Introduction
Safflower (Carthamus tinctorius L.) is a significant oilseed crop adapted to lower rainfall and lower input farming. It is cultivated primarily in Kazakhstan, China, India, and the United States. Despite being a minor crop, safflower plays an important role in farming systems due to its extensive root system, which allows it to tolerate water deficit conditions.

Materials and Methods
The experiment was conducted at the Research field of the University of Maragheh. The study area has a Mediterranean climate with low annual precipitation. The safflower cultivar "Goldasht" was used, and the experimental design was a split plot in randomized complete block design with three replications.

Results
Results indicated that both sulfur and nano-metal applications significantly improved morphological traits and seed yield. The highest yield was associated with the combined application of sulfur and nano-chelated Zn. The study concludes that integrated application of sulfur and nano-chelated metals can significantly enhance safflower growth and yield in semi-arid regions.