Effects of different irrigation levels and salinity on qualitative and quantitative yield of sugar beet

To determine the effects of different irrigation and salinity levels on qualitative and quantitative yield of sugar beet, an experiment was conducted for two years (2006-07)at Torogh Agricultural Research Center, Mashhad, Iran, using two sprinkler systems. Each of the two irrigation systems was connected to two water sources with 1 and 6 ds/m salinity. Irrigation was performed via two sprinkler pipes (line source) that were placed perpendicular to each other in a 28×28 m area. In each irrigation, sugar beet plants planted at the center of the square could receive full irrigation and less water was given to farther plants. Consequently, the salinity level was changed from 1 to 5.75 ds/m. At the end of each irrigation, water level and the salinity rate of the can samples located at the center of the square networks of 2 × 2 m2 were measured. At the end of the growing season, beet samples were harvested from an area of 3 m2 around each can and their yields were determined. Using the data obtained from each network, the quantity of water, average salinity level and quantitative and qualitative yield of sugar beet were measured. Results showed that root yield and sugar content were influenced by irrigation level and electrical conductivity (EC) of the water applied. With increase in irrigation level (with different ECs), root yield and sugar content were increased, and by increasing EC (in the same water levels), root yield and sugar content were decreased. The correlations of sugar content and impurities with irrigation level and EC were not statistically significant.