Two field experiments were conducted at the experimental farm of Tag El

Ezz Agric. Res. station. Dakahlia during 2004/2005 and 200512006 seasons to study

the effect of three antioxidant substances (hydroquinone, citric acid and benzoic acid

at concentratåons of 5, lo and 15mM) on growth, yield and yield components of three

faba bean cultiva rs (Sakha 1, Giza 3 and Giza 2) as well as the severity of chocolate

spot disease caused by Botiytis fabae. Generally, the application of benzoic acid at

any concentration showed priority and proved to be the best and most effective ¡n

reducing disease severity on all tested cutivars. Hydroquinone came ¡n the second

order as compared to control treatment. Citric acid showed the lowest effect in this

respect.

The foliar application of antioxidants on (aba bean cultivars significantly

increased growth and yield components which could be summarized as follows: 1)

Sakha 1 cultivar surpassed Giza 3 and Giza 2 in number of branches, number of pods

and seed weight planf', 100-seed weight and seed yield, but Giza 3 cultivar

surpassed Sakha 1 and Giza 2 in plant height and straw yield ¡n the two seasons, 2

Citric acid gave the highly significant increase ¡n number of pods & seed weight plnf

and seed yield in both seasons 3) Using 15mM of antioxidant substances ave higher

significant increase ¡n number of branches, pods and seed weight planf, 100-seed

weight and seed yield compared with control and 4) The interaction between (aba

bean cultivars and antioxidants had a significant effect on plant height in both seasons

and on the 100-seed weight and seed yield in the first and second seasons. Sakha 1

with citric acid was more effective ¡n this respect.