Effect of Field Dodder (Cuscuta campestris) on Some Physiological and YieldTraits of Sugarbeet (Beta vulgaris)

Due to its favorable weather conditions, west Azarbayejan province is the second-largest producer of sugar beet in Iran. Weeds, especially field dodder, is one of the most important components that has negative effects on the quality and quantity of sugarbeet. In order to evaluate the effect of field dodder on the photosynthetic pigments and yield (quality and quantity) of sugar beet, a study using paired t-test was carried out on four farms in Urmieh-West Azarbayejan, during 2014. Studied farms had similar date of planting (first ten days of April), uniform density (8 plants per square meter) and same cultivar (Ecbatan). In this research, 30 healthy plants and 30 plants infected with field dodder were selected from each farm. Physiological and tecnicall characteristics were evaluated at the established plant stage (8-12 leaves) and at the harvest stage of sugerbeet Results showed that dodder affected efficiency of photosynthesis on sugarbeet leaves, such that it reduced chlorophylls a and b and total chlorophyll by 30,18, and 38% respectively, but the amount of carotene was not affected. It also reduced yield by 25%, root sugar content by 108%, impure sugar by 18.5% and foliage dry weight by 18%. Dodder also increased root nitrogen content by 37.3%, but had no effect on potassium content.