Effects of Marjoram, Amino and Humic Acid on Nitrogen Content, Quantitative and Qualitative Characteristics and Shelf Life of Bell Pepper cv. Inspiration

Amiri, Faraz; Aboutalebi-Jahromi, Abdolhossein; Zakerin, AbdolRasoul; Hassanzadeh-Khankahdani, Hamed; Ejraei, Abdolkarim

doi:10.22034/jmpb.2026.371178.2080

Effects of Marjoram, Amino and Humic Acid on Nitrogen Content, Quantitative and Qualitative Characteristics and Shelf Life of Bell Pepper cv. Inspiration

Articles in Press

Document Type : Research Article

Authors

¹ Department of Horticultural Science, Faculty of Agriculture and Natural Resources, Islamic Azad University, Jahrom Branch, Fars Province, Iran

² Horticulture Department of Agricultural Jihad Organization, Shiraz, Fars Province, Islamic Republic of Iran

10.22034/jmpb.2026.371178.2080

Abstract

This study investigated the effects of marjoram (Origanum majorana) extract, amino acids, and humic acid on several agronomic and chemical characteristics, as well as the post-harvest shelf life of greenhouse bell peppers (cv. ‘Inspiration’). The experimental design comprised ten treatments: a control, three concentrations of humic acid (0.2, 0.4, and 0.6 g/L), amino acids (0.5, 1, and 1.5 g/L), and marjoram extract (3%, 6%, and 9%). These treatments were applied via foliar application for 12 consecutive weeks, starting five days after seedling transplanting once the plants were fully established. The experiment was conducted in a randomized complete block design (RCBD) with ten treatments, each replicated three times, with each replicate consisting of three bell pepper plants. Following analysis of variance (ANOVA), mean comparisons were performed using the Least Significant Difference (LSD) test at the 5% and 1% probability levels. Furthermore, a separate factorial experiment was conducted to evaluate fruit weight loss, considering two factors: (A) treatments and (B) storage duration. Post-treatment measurements included fruit nitrate and nitrite levels, calcium and potassium content, fruit diameter, fruit number per plant, and the percentage of weight loss at 14 and 21days post-harvest. The results indicated that the 0.6 g/L humic acid treatment resulted in the lowest nitrite levels, while the 1.5 g/L amino acid treatment yielded the lowest fruit nitrate content. Additionally, the marjoram extract demonstrated the most favorable results regarding fruit calcium and potassium levels, fruit diameter, and yield (number of fruits per plant). Furthermore, this study revealed a significant positive impact on reducing post-harvest weight loss. These findings provide valuable practical insights for agricultural producers, stakeholders, and consumers in sustainable crop management.

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