Effects of simulated acidic rain on yields of field-grown radishes and garden beets

Experiments were performed to determine the effects of simulated acidic rain on yields of garden beet and radish grown under standard agronomic practices. Plots were exposed to small additions of simulated rain with pH levels of 5.7, 4.0, 3.1, and 2.7. The spray-to-wet simulated rain applications had volumes similar to those of most ambient summer rainfalls. Some plots received no simulated rain applications. All plants were exposed to ambient rainfalls at Brookhaven National Laboratory (Upton, NY, U.S.A.) which had a mean weighted pH of 4.06 during the summer of 1980. Root mass of radishes was not significantly affected by simulated acidic rain exposures. Root yields of beets exposed to simulated rain applications at pH 5.7, 4.0, 3.1, and 2.7 were 110, 70, 84 and 86% of beets receiving ambient rainfalls only. Foliar injury observed on beets was attributed to exposure to both simulated acidic rain and ambient rainfalls with a mean weighted pH of 3.88. This is the first experiment where visible foliar injury has occurred due to both ambient rain and simulated rain applications above pH 3.1 under standard agronomic conditions.