Lack of physiological response of two corn hybrids to simulated acid rain

Simulated acid rain has been reported to cause physiological changes in various plant species. Studies were conducted in 1983, 1984 and 1985 to determine the effect of acid rain on some physiological parameters in two corn (Zea mays L.) hybrids. Simulated rain of pH 3.0, 4.2, and 5.6 was applied throughout the growing season onto plots protected from ambient rain and grown on a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll). Individual plants were evaluated for change in leaf CO₂ fixation, water potentials, chlorophyll content, and in vitro pollen germination. Rain pH did not affect any of these parameters. Within the limits of experimental error, it must be concluded that simulated acid rain of pH 3.0 did not affect the physiological parameters measured in this study.