An environmental problem was recorded in broad bean crop cultivated in Noubareya region during season 2013. Harvested broad bean seeds were obtained by satisfactory evidence of weak economic value.
An attempt of seed treatment process was carried out in this study to inhibit fungal growth and mycotoxins produced by Alternaria alternata and Penicillium citrinum in field during cultivation process using sorbic and benzoic acids at 10 and 15 ppm,; ethyl sorbate and/or ethyl benzoate at 5 and10 ppm  for each treatment as alternative to the fungicides metalaxyl DS  and ridomil MZ72WP at recommended rate (x) and 1 ½  recommended rate  applied for seed protection during cultivation process.
The germination test showed the failure of all the tested preservative treatments to germinate seeds. Therefore; all treatments were used as foliar seedlings  spray applied 3 times every 15 days during  the experiment (60 days) . The   results of fungicidal activity indicated that the use of preservative up to 10 ppm totally inhibited fungal growth except ethyl benzoate and ethyl sorbate which completely inhibited fungi at 5ppm Moreover, 5 and 10 ppm concs realized the same inhibition rate exerted by metalaxyl and ridomil MZ at 1.5 x. Untreated plants showed higher death ratios, compared with treated ones. Ridomil MZ at conc. 1.5 x reduced dead plants 60% followed by benzoic acid 56% at conc.5 ppm.    Furthermore, the ester form of both benzoic and sorbic acids were more effective in reducing AOH and CTN than the other tested fungicides.  metalaxyl and ridomil MZ at 1.5 x. Ridomil MZ at conc. 1.5 x reduced dead plants 60% followed by benzoic acid 56% at conc.5ppm. Furthermore, the ester form of both benzoic and sorbic acids acids were more effective in reducing altrnariol (AOH) and citrinin (CTN) than the other tested fungicides. Accordingly they can act successfully as fungicides alternatives.
Benzoic acid has been actively playing a great role as antifungal and detoxifier agent. Meanwhile, it affected plant growth which badly in need for more studies to avoid these side effects.