Two field and storage experiments were conducted at a private farm near the high ways and Delta company for fertilizers and chemical industries, Talka City, Dakahlia Governorate during the two successive summer seasons of 2009 and 2010 to study the effect of some heavy metals such as copper, lead and manganese by using natural antioxidants substances, i.e., humic acid, vitamin C., vitamin E. and glutathione on tomato (Lycopirsecon esculentum Mill) cv. Alissa and kidney bean (Phaseolus vulgaris L) cv. Giza 3 plants under soil pollution stress. It also aimed to improve the quality and storability of tomato and kidney bean fruits.
The most important finding could be summarized as follows:
Concerning the effect of the treatments on tomato the obtained results indicate that all natural substances of antioxidant led to significant increases in all vegetative growth parameters compared to the control.
Application of glutathione and vitamin C had a significant effect on plant height, chlorophyll a, chlorophyll b, fresh weight per plant, fruit number per plant and total fruit yield per feddan in both season of this study.
The plant organs (roots, leaves and fruits) for the tomatoes differed in its content from the heavy metals, where the roots contained higher amount of these elements content (Pb, Mn and Cu) than the leaves, while the fruits have the suitable levels of heavy metals content, and that due to the impact of the treatments on the removal of these poisonous elements. Glutathione and vitamin C treatments had a highest significant effect in this respect. The control treatment led to an accumulation of the respective heavy metals content in different plant organs.
All natural substances of antioxidants had a significant increases in quality and storability parameters of tomato fruits, expressed as a reduction in weight loss and decay percent and the preservation of the fruits contents (i.e., acidity, lycopene content, firmness, vitamin C and T.S.S) in comparison with the control of these treatments in both seasons.
While, the effect of application of glutathione and vitamin E had a significant effect on most vegetative growth parameters of kidney bean in both seasons of this study.
Glutathione, vitamin C and vitamin E treatments led to significant decrease in heavy metals content (Pb, Mn and Cu) in different plant organs of kidney bean (roots, leaves and fruits) compared to the control treatment in both seasons.
All antioxidant treatments gave significant increases of the fruits quality and improvement storability compared to the control in the two seasons.
It could be concluded that application of glutathione, vitamin C and vitamin E as a natural substances of antioxidants to tomato and kidney bean plants indicated that the most effective treatments for improvement quality and storability and alleviate the adverse effects of some heavy metals under soil pollution conditions.