Drought stress effect on abscisic acid accumulation and stomatal conductivity of sugar beet

Drought stress is one of the limiting factors in crop producton. In order to estimate drought stress effects on ABA accumulation and stomatal conductivity of sugar beet (Beta vulgaris L.) leaves, an experiment was conducted in Karaj and Mashhad, in 1999. Research was carried out in factorial experiment based on RCBD with 3 replications. In this experiment 9 genotypes of sugar beet were tested. Treatments were water stress (50 days non irrigation in early growth period) and non stress. Results showed that drought stress significantly affected the ABA accumulation in leaves, and genotype × stress interaction was also significant. White sugar yield genotypes decreased as ABA increased in drought stress treatment. The correlation coefficient between root yield and ABA accumulation was low and non-significant. It is concluded that genotypes had enough time after drought stress to compensate for their yields. Stomatal conductivity decreased when ABA increased. It was due to stomatal closure and decreasing the transpiration.