Effect of citric acid, tartaric acid, sodium citrate, sodium salicylate, sodium benzoate, and ammonium tartarate, as antioxidants, was tested on the radial growth of Sclerotium apivavm Berk. The effect on disease incidence and yield of onion as well as garlic was determined. The tested antioxidants at 10mM gave the best results in reducing the radial growth, especially sodium benzoate that gave 2.4 cm radial growth compared to 8.75 cm. for the non-treated control. The number of sderotia was deceased by the used antioxidants regardless of the concentrations. No dear correlation was observed between the effect of the tested antioxidants on the radial growth and the formation of sderotia. Feld experiments for two seasons, 2002 and 2003, using a concentration of 10 mM in treating onion transplants or garlic doves for one hour were carried out at Mallawy research station. The efficiency of the antioxidants In controlling white rot was 88.5% and 87.9% In onion, while it was 60% and 70.50% in garlic in 2002 and 2003, respectively. Regarding the yield, the use of the antioxidants increased onion yield by 498.2% and 355.5% compared to the non-treated control as well as 122.1% and 234.9% in garlic in 2002 and 2003. respectively. The chemical analyses of healthy or infected antioxidant-treated onion bulbs or garlic doves indicated a higher phenolic content in heathy onion bulbs than in the infected ones and similar trend was observed for garlic. Regarding the amino acids, methionine, cysteine and cystine were found in onion, while cystine and cysteine were detected in garlic. Data Indicated higher amounts of the amino adds in healthy samples than in the infected ones both in onion and garlic.