Influence of Meteorological Conditions and Agronomical Practices upon Attack of Sunflower by Sclerotinia White Rot (Sclerotinia sclerotiorum Lib.)

V. ALEXANDROV1 and M. ANGELOVA2
1 Plant Protection Institute, BG-2230 Kostinbrod, Bulgaria
2 Institute of Corn, Kneza – Basis Lom, BG-3600 Lom, Bulgaria

Absract

ALEXANDROV, V. and M. ANGELOVA, 2004. Influence of meteorological conditions and agronomical practices upon attack on sunflower by Sclerotinia white rot (Sclerotinia sclerotiorum Lib.). Bulg. J. Agric. Sci., 10: 185–189

The influence of meteorological conditions, date of sowing and density of sunflower crop upon the attack by the Sclerotinia white rot (S. sclerotiorum Lib.) is studied in the period 1991–1994 at the soil-climatic conditions of Northwest Bulgaria. It is determined that the disease incidence is higher at the later stages of the crop development. The meteorological conditions influence on the attack by Sclerotinia white rot. The attack in years with higher rainfall during vegetation is stronger. The early sow's date favored for the incidence of Sclerotinia white rot. The attack by the disease depends very much on the density of the sowing. The higher is the number of plants per dka the higher is the disease infestation level. The hybrid Albena is most sensitivity to the Sclerotinia white rot compared to other studied varieties.

Key words: sunflower, Sclerotinia sclerotiorum Lib., meteorological conditions, agronomical practices