One of the aims in breeding sugar beet is to develop varieties with a low range of yield reduction where the deficiency of water occurs. The aim of this study was to investigate the sugar beet genotypes whose yield reduction was minimum when water deficiency conditions occur. For this purpose 145 sugar beet genotypes were studied in five experiments during a period of two years at S.B.S.I. Index of susceptibility (s) to drought stress in genotypes was also calculated. A low root yield which was caused by water deficiency , was observed in the experiments for both years (1991 & 1992), and genotypes showed different reactions to water stress. The results showed that drought caused an increase in the sugar content, amounts of potassium, amino N and alkalinity. Water deficiency resulted in a relatively low which sugar yield per hectar and an increase of 2 to 3 percent in sugar content in the root which can not compensate for sugar yield reduction due to low root yield caused by water stress. Variety pp 22 and lines 16459 and 14062 were found to have the highest tolerance to drought conditions.
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