New Approach to Control Sclerotium rolfsii Induced Sugar Beet Root Rots Disease by Trichoderma with Improved Sucrose Contents

In Egypt, sugar beet (Beta vulgaris L.) has become a major sugar manufacturing plant in latest years. It is recognized that sugar beet damaged by different pathogens, including root rot disease caused by Sclerotium rollsii, in terms of quantity and quality. The aim of the current study was to control the disease of the root rot sugar beet and determine the sucrose content during two successive cropping seasons. Trichoderma harzianum kj831197 produced b- glucanase enzymes that play a key role in fungal disease biocontrol. Twenty two bioactive isolates were tested for the activity of b- glucanases, ten of which are Trichoderma spp strains. Sclerotium rolfsii radial growth has been suppressed with efficiency ranging from 77.77 to 91.11% in dual culture technique. The Vitavax200 fungicide increased control of the disease under greenhouse conditions followed by a combination of b- glucanase enzyme with Trichoderma harzianum kj831197 spore suspension. The use of b- glucanase enzyme mixed with Trichoderma harizianum kj831197 cells leads to an increase above other treatments in the total soluble solid and sucrose content of the sugar beet. Despite the fungicide Vitavax200, the overall soluble solid and sucrose content were significantly affected by disease control but the sugar beets yield was lowered.