In the summer season, the heat poses a challenge to open-field tomato production, leading to decreased yields. As a result, we conducted a study to examine the impact of various foliar spray compositions on enhancing nutrient absorption and increasing fruit yield in tomato plants. The experiment consisted of two factors: Hybrids [Nirouz (TH99806) and 023] as the main factor, while the sub-main factor was potassium silicate (P3: 3 mL L^-1) or/and fulvic acid (F2: 2 mL L^-1), and CK (H₂O) as a control. The plants were sprayed three times, the first time was after 30 days from transplanting the seedlings, the second time was after 20 days from the first time, and the third time was after 20 days from the second time. As a result, P3 generated the highest yield in plants compared with the other treatments. Also, Foliar spraying with P3+F2 increased the leaf content of chlorophyll a, carotene and TSS. Thus, P3 and P3+F2 stimulated the plant nutrient uptake, which improved the marketable yield. So, we recommend foliar spraying with potassium silicate at a rate of 3 mL per liter of water to avoid heat stress on tomato plants.