Effect of drought stress on antioxidant enzyme activities and root yield of sugar beet (Beta vulgaris).

The growth and development of plants are severely restricted by a variety of environmental stresses. Therefore, in order to evaluate the response of antioxidant defense system of three sugar beet genotypes to drought stress and improving soil water content management, a field experiment was conducted in a randomized complete block design under split plot arrangement with four replications at the Research Site of Sugar Beet Seed Institute in Karaj, Iran during 2008 and 2009 growing seasons. Irrigation treatments arranged in main plots during growing seasons included: 80 mm (I : as control), 130 mm (I ) and 180 mm (I ) evaporation from A class 1 23