Effect of Air Pollution and Ethylene Diurea on Broad Bean Plants Grown at Two Localities in KSA

The primary objectives of this investigation were to examine the interactive effects of air quality treatments and ethylene-diurea (EDU) on physiological characteristics of broad beans (Vicia faba L. cv. Lara) during its whole growth. Ethylene-diurea (EDU) was used as a factor to evaluate O3 pollution impact on plant growth. Leaf samples were collected from upper canopy positions six times (pre-EDU addition, week after four EDU`s addition, at the time of harvesting). Maximal differences in leaf carbohydrate and pigments were observed in response to EDU applications. Significant reduction were noted for air quality treatments regarding carbohydrate and pigment fractions. Minimal differences were found for first EDU application while maximal ones were recorded at 200 mg L-1 of treatments. The EDU treatments stimulated carbohydrate and pigment contents at the upper canopy position with higher levels. The stimulation in leaf carbohydrates by the EDU treatment, compared to the non-treated EDU, provides a rational explanation for the counteracting effects of EDU against moderate exposures to O3.