Attack on Sunflower by Charcoal Rot (Sclerotium bataticola T.) under the Influence of Climate and Mineral Fertilization

V. ALEXANDROV and V. KOTEVA
Institute for Agriculture, BG-8400 Karnobat, Bulgaria

Abstract

ALEXANDROV, V. and V. KOTEVA, 2001. Attack on sunflower by charcoal rot (Sclerotium bataticola T.) under the influence of climate and mineral fertilization. Bulg. J. Agric. Sci., 7: 271-274

The influence of the growing rates of nitrogen, phosphorus and potassium of fertilization upon the attack of the charcoal rot on the sunflower (caused by Sclerotium bataticola Taub.) is studied in a long-lasting stationary fertilization experiment. The plants attack by the disease is determined in the period 1996-1998 in the stage of full ripeness of the sunflower (hybrid Albena).
It was determined, that the damp conditions influence on the attack of the charcoal rot on the sunflower. The appearing of the disease is stronger in the years with well expressed drying up. The percentage of attacked plants increases from the variant without fertilization towards the variants with higher fertilization rate, and it’s the biggest one in the variant with the highest rate of fertilization. The attack’s index increase in the same way. The highest percentage of attacked plants by the disease are noticed in cases of fertilization rates of: T2-N10P6K6 and T3-N15P8K8, when the yield of seeds decreases by 20-24%.

Key words: sunflower, charcoal rot, attack, climate, mineral fertilization, Sclerotium bataticola T.