Sweet onions (Allium cepa L.) are becoming increasingly popular due to their mild, sweet flavor and low pungency. Consequently, enhancing their pre- and post-harvest quality attributes has emerged as a key area of research. One promising method is seed nanopriming, where seeds are pre-treated with nanoparticles (NPs) to improve germination, overall plant growth, and quality. Zinc (Zn) plays a crucial role in plant metabolism, acting as a cofactor for various enzymes involved in processes like auxin production and chlorophyll synthesis, and onions are particularly sensitive to Zn deficiency. This study investigated seed nanopriming in four onion varieties: two yellow commercial types (Legend Onion and Pecos Onion) and two Texas A
