Soil-Borne Pathogen-Mediated Root Rot Diseases of Sugar Beet and Their Management

Abstract

Sugar beet (Beta vulgaris L.) is the most important, nutritious, and forage crop globally. World's one fourth of sugar production is dependent only on sugar beet crop. Every year, farmers suffer a havoc production loss due to biotic stresses. Soil-borne pathogen-mediated root rot diseases of sugar beet are considered as a key constrain for beet cultivation. Various soil-borne pathogens like Rhizoctonia solani, Macrophomina phaseolina, Sclerotium rolfsii, Aphanomyces cochlioides, Phytophthora drechsleri, Fusarium oxysporum f.sp. radicis-betae, and Phoma sp. cause root rot symptoms. Various symptomatic characterizations such as wilting of whole shoot system, brownish-black discoloration at the petiole, and rotting of root with cracked holes on the upper surface are observed in infected plant. Disease progress maximally depends on susceptible epidemiological factors which have a crucial role in pathogenesis. Disease incidence level varies from 25 to 65% in minor to major infected plants, although all the pathogenic attacks may not occur in the same time. Yield loss can be estimated by the production loss which is because of reduced sugar quantity at the farm stage and postharvest losses in storage. Application of disease and stress resistant varieties, biological and cultural practices, chemical method, and soil quality control (water holding capacity, micro-macro nutrient deficiency, soil pH, soil salinity) are the possible management practices against root rot disease.