Growth and Physiological Responses of Tomato (lycopersicon Esculentum Mill.) to Simulated Acid Rain

This investigation was undertaken to ascertain the effect of simulated acid rain (SAR) on growth, yield and physiological parameters of tomato. SAR exposure (pH 3.0 and 4.0) caused white-to-tan spots on the abaxial and adaxial surface of tomato leaves. SAR exposure at pH 3.0 and 4.0 significantly suppressed pigment synthesis, shoot and root dry weights and yield of tomato. The effects were more pronounced at lower pH 3.0. Reducing and nonreducing sugars were significantly diminished to varying degree by SAR solutions of pH 3.0 and 4.0 and the effect being more accentuated at pH 3.0. Nonreducing sugars declined to a greater extent than did the reducing sugars and this effect was more pronounced in SAR-treatment of pH 3.0. SAR-exposure of pH 3.0 and 4.0 resulted in accumulation of soluble phenols as an induced mechanism against SAR stress. The results are discussed in the light of physiological responses of plants to abiotic stresses.