Extended Abstract
1.      Introduction: Zinc (Zn) and manganese (Mn) are essential micronutrients required to enhance crop growth and yield, and to balance these nutrients in plants.  The essentiality of Zn and Mn for plants has been well established, as both are essential micronutrients involved in a number of essential functions. Zn, an essential micronutrient, plays a vital role in various processes such as carbohydrate, auxin, and nucleic acid metabolism, protein synthesis, membrane stabilization, and in the detoxification of highly active superoxide radicals. Soils in many arid and semi-arid regions of Iran, due to high pH and low organic matter, are faced with Zn and Mn deficiencies. Pea, a member of the Fabaceae family, is one of the most widely used winter vegetables. Pea has high nutritional value, having proteins (21–32%) and starch (37– 49%) content, water-soluble fibers, vitamins, minerals, and phytochemicals. Therefore, we carried out the present study to observe the effect of foliar spray of Zn and Mn on the yield and quality of pea seeds.
2.      Materials and Methods: To investigate the effect of foliar application of Zn and Mn on growth, yield, and quality of pea (Pisum sativum cv. Stardust), a factorial experiment based on a randomized complete block design with three replications was conducted in Reasech field of university of Zanjan during 2023. Experimental treatments included three levels of Zn (0, 2, and 4%, Zinc sulfate) and three levels of Mn (0, 2, and 4%, manganese sulfate). Seeds pea were sown on 11 Marc, 2024, with 2.5 cm, 25 cm spacing within row and 40 cm spacing between rows. Different concentrations of zinc sulfate (Zn; 0, 2, and 4 %) and manganese sulfate (Mn; 0, 2, and 4 %) were sprayed on the plant at the 5–6th true leaf and flowering stages using a mechanical mist sprayer. Irrigation was calculated based on actual evapotranspiration (ETc%) rates. All necessary management practices, such as weed control, were performed according to the recommended package of practices during crop growth. During the growth period and after crop harvest, the plant height, chlorophyll index, pods number/plant, pod fresh weight, seeds number/pod, seed fresh weight, and yield, total soluble solids (TSS), and protein contents, the amount of zinc and manganese elements in seeds were evaluated. 
3.      Results and Discussion: ZnSO4 and MnSO4 at different concentrations resulted in a significant increase in growth, yield, and quality of pea seeds as compared to control plants. Provitamin studies suggested that the depression in plant growth was due to a decrease in auxin concentration in Zn-deficient plants. The foliar application of Zn and Mn had a significant effect on the number per pod, the weight of seeds per pod, pod fresh weight, chlorophyll index, seed protein content, but had no significant effect on plant height, pod dry weight, pod yield per plant, and total soluble solids content. The pod and seed weight of plants receiving foliar treatments was significantly higher than that of control plants. The highest seeds weight/pod (3.92), seeds number/pod (8.66), pod fresh weight (5.97), and chlorophyll index (87.13) were obtained with the application of Zn 4% and Mn 4%. Numerous research studies have highlighted the roles and importance of Zn and Mn in enhancing crop yield and production. Foliar application of Zn and Mn, compared to control plants, improved the concentration of total protein content of seeds. The decrease in protein concentration in seed control plants might be due to a sharp reduction in RNA polymerase activity, deformation of ribosomes, and enhanced RNase activity in Zn-deficient plants. Also, foliar application of ZnSO4 and MnSO4 resulted in a significant increase in Zn and Mn content in the seeds as compared to control plants, and the highest content of Zn (78.1 mg g-1) and Mn (46.1 mg g-1) was observed in plants treated with 2% Zn and 4% Mn.
4.      Conclusion: Zinc and Mn are essential micronutrient minerals that are required by pea, an important pulse crop, which can retain and enhance the productivity as well as the nutritional value of the crop through biofortification for higher food quality. The present study clarified that the supplementation of ZnSO4 influenced the yield and quality of pea. The use of ZnSO4 (4%) and MnSO4 (4%) at growth and flowering stages improved the TSS, Zn, Mn, protein content, and grain yield over the control. Thus, the present study demonstrated that biofortification through the foliar application of ZnSO4 and MnSO4 could be considered the most effective treatment for improving food quality parameters and yield of pea.