Distribution of Rhizomania Disease in Sugar Beet Growing Areas of Turkey

Abstract

Rhizomania is one of the most destructive diseases affecting sugar beet. It leads to a severe loss in terms of root yield and sugar content up to 90 % and up to 70 % respectively, depending on the disease severity. It was reported in some regions of Marmara, Central Black Sea, and Central Anatolia and tends to spread in other regions in Turkey. The disease is caused by Beet Necrotic Yellow Vein Benyvirus (BNYVV) and transmitted by a fungus, Polymyxa betae. The primary source of its spread is through the movement of infested soils or beets. Only cultural control methods are employed to control this disease. At present, the most effective control measure is to use of partially resistant sugar beet cultivars. The other additional measures like planting early into cool soils, minimizing watering, avoiding soil compaction, and employing crop rotations can reduce levels of the virus in the soil. Therefore, it is essential to determine the infested areas and take cultural measures before the disease causes economically important yield losses. Based on a three-year crop rotation, surveys were conducted and sugar beet root samples were collected from the growing areas in 102 regions of 17 sugar factory boundaries and in three periods including 1996-1998, 1999-2001 and 2002-2004. These root samples were tested by means of DAS-ELISA and distribution of BNYVV was determined. Rhizomania was detected in the sugar beet production areas of 4, 9 and 15 sugar factories in 1996-1998 1999-2001, and 2002- 2004 at the rates of 19.30% (46200 ha), 31.42% (94140 ha), and 48.66% (203640 ha), respectively.