This study was carried out to study the effect of safe alternatives as compared to hydrogen cyanamide on breaking
dormancy of" Flame seedless" grapevines. The vines were subjected the following spray treatments; control, garlic oil,
hydrogen peroxide, copper sulphate, zinc sulphate, boric acid and hydrogen cyanamide in the second week of January. All
treatments except zinc sulphate in the second season had higher bud burst% than control. The results also showed that
copper sulphate and hydrogen cyanamide applications significantly increased bud burst % than other treatments in both
seasons. In both seasons, hydrogen cyanamide gave higher yield and juice volume than the rest treatments, except
hydrogen peroxide for yield in the second season. Hydrogen cyanamide and zinc sulphate applications increased cluster
weight in the second season only. Weight and size of 100 berries were significantly increased by copper and zinc sulphate
and hydrogen cyanamide. In the first season, copper sulphate and hydrogen peroxide treatments increased berry length
and diameter. On the other hand, the results showed that there were non significant differences among tested treatments
concerning berry length and diameter in the second season and L/D ratio in both seasons. In the first season, the highest
percentage of T.S.S was obtained by vines sprayed with garlic oil. In the second season, T.S.S% was not affected by
different applications. Data showed that zinc, copper sulphate and garlic oil significantly decreased acidity in the second
season. The results in both seasons indicated that garlic oil, copper and zinc sulphate applications lead to increase
T.S.S/acid ratio. The data in both seasons indicated that anthocyanin content was increased by garlic oil treatment. In both
seasons, garlic oil and hydrogen cyanamide considerable increased shoot length. Hydrogen peroxide caused increase in
fruitfulness%, number of clusters and leaves in both seasons. Generally, there were non significant differences among
used treatments concerning peroxidase activity. Catalase activity was highly increased with bud burst which appeared as
achromatic zone with high intensity in all treatments, except boric acid in the first season and copper, zinc sulphate and
hydrogen cyanamide treatments in the second season.