Simple aromatic acids and their salts in controlling the growth of Rhizoctonia solani under laboratory conditions

Abstract

Rhizoctonia solani is a fungus pathogenic in many economically important plants. Ten aromatic acids were examined for activity against Rhizoctonia solani using poisoned food technique. All the acids were inhibitory to R. solani. Three of the acids, at concentrations around 0.015% (g/ml), completely inhibited the growth of the fungus. Efforts were made to enhance the solubility of chosen aromatic acids in aqueous solutions by using sodium salts, potassium salts or preparing inclusion complexes with -cyclodextrin. Sodium, potassium salts of the five acids and the use of cyclodextrin in the aqueous solution did not enhance the antifungal activity against R. solani. Soil Fungicide Screening Test on selected aromatic acids showed that cinnamic acid (compound 2) is better in controlling the growth of R. solani in paddy field mud and phenylpenta-2,5-dienoic acid (compound 4) is better in controlling the same fungus in garden soil.