A field experiment was conducted on sweet pepper plants (Capsicum annuum L.) Sensei F1 hybrid at the Research Farm of Vegetables, Faculty of Agriculture, Benha University, Qalubia Governorate, Egypt, in the winter seasons of 2022/2023 and 2023/2024 under plastic greenhouse to examine the response of foliar application with four stimulants: proline at 100 ppm, salicylic acid at 500 ppm, melatonin at 100 ppm, or potassium silicate at 4 ml.L-1 as well as spray with tap water on sweet pepper plants under drought conditions. The largest values for all evaluated growth characteristics, photosynthetic pigments, macronutrient content (NPK) and total carbohydrates, as well as yield and its components with the best physical and chemical quality, were found when plants were sprayed with potassium silicate at 4 ml.L-1, followed by salicylic acid at 500 ppm every 15 days starting 30 days after transplanting under irrigation level 100% field capacity, followed by 80% field capacity. The lowest proline content, however, was found when plants were sprayed with 100 ppm of proline with 100% field capacity irrigation. However, except for proline concentration, irrigation using 60% field capacity and tap water as a foliar spray (control) exhibited the lowest values in every characteristic under study. Additionally, it was demonstrated that foliar treatment can produce excellent yields with high physical and chemical quality while reducing irrigation needs by 20%. |
