عنوان مقاله [English]
Sclerotinia minor is one of the most important causal agents of sunflower root and crown rot in the world Iran. In current study, isolation, purification and identification of the fungus was carried out from sunflower farms at Khoy city, Iran and pathogenicity test and sclerotia propagation was done using Köhn method. The effect of 1, 5 and 10 g/L of urea and phosphorous fertilizer and 10, 15 and 20 g/L of animal manure including chicken, sheep and cow manure was studied on growth of mycelial disc and sclerotium on potato dextrose agar medium. Also, the effect of mentioned fertilizers was evaluated on disease development and some morphological traits of sunflower in greenhouse condition. Despite inhibitive effect of chemical fertilizer especially urea in laboratory conditions on fungus mycelial growth and sclerotium production, they caused higher sclerotinia disease index in greenhouse conditions. Therefore, chemical fertilizers such as urea and phorphorus fertilizer are synergic on sclerotinia disease in sunflower and replacement of animal manure specially cow and sheep manures are recommending.