Larsen B R
Ecotoxicol Environ Saf. 1985 Oct;10(2):228-38. doi: 10.1016/0147-6513(85)90070-3.
The effect of foliar-applicated (+/-)-2-(2,4-dichlorophenoxy)propanoic acid (2,4-DP) under simultaneous influence of simulated acid rain at pH levels of 3.3, 4.3, and 5.6 was examined for young plants of white mustard, rape, cress, lettuce, radish, carrot, oat, and barley grown in climate chambers. After 1-2 weeks with daily showers plants received a single foliar application of 2,4-DP in aqueous solution (500 microliter; 0.25-50.0 mg X liter-1). After a post-treatment period of 2-3 weeks with daily showers the plants were sampled. 2,4-DP at 5 mg X liter-1 or higher concentrations caused various symptoms for the dicotyledons. Monocotyledons and carrot remained unaffected. The application of acid rain at pH 3.3 produced morphological changes, increased the symptoms from 2,4-DP, and reduced the dry weight and the leaf to stem ratio. Cress exposed only to acid rain showed necrotic spots and chlorosis at pH 3.3. By decreasing pH taller plants with smaller leaves were observed. The combined effect of acid rain and 2,4-DP was additive rather than synergistic.
在气候箱中种植的白芥、油菜、水芹、生菜、萝卜、胡萝卜、燕麦和大麦的幼苗，研究了在pH值分别为3.3、4.3和5.6的模拟酸雨同时影响下，叶面喷施（±）-2-（2,4-二氯苯氧基）丙酸（2,4-DP）的效果。在每天喷淋1-2周后，植株叶面单次喷施2,4-DP水溶液（500微升；0.25-50.0毫克/升）。在每天喷淋的2-3周后处理期后，对植株进行采样。5毫克/升或更高浓度的2,4-DP对双子叶植物产生了各种症状。单子叶植物和胡萝卜未受影响。pH值为3.3的酸雨处理导致形态变化，加重了2,4-DP的症状，并降低了干重和叶茎比。仅暴露于酸雨下的水芹在pH值为3.3时出现坏死斑和黄化。随着pH值降低，观察到植株更高但叶片更小。酸雨和2,4-DP的联合作用是相加的，而非协同的。
