Wirkungen flilssiger Stickstoffdiingemittel auf phytopathogene Bodenpilze: Effects of Liquid Nitrogen Fertilizers on Phytopathogenetic Soil Fungi

Summary The effects of two liquid nitrogen fertilizers (I = ammonia solution, 25%; II = ammonia solution ,Schwarze Pumpe", 15%) at concentrations of 50, 200 and 800 ppm NH3-N on the growth of the phytopathogenic soil fungi Rhizoctonia solani Kuhn, Fusarium oxysporum f. sp. gladioli Schl., Pythium debaryanum Hesse and Sclerotinia sclerotiorum (Lib.) de Bary were studied on liquid culture medium. Mycelium growth was severely inhibited by both fertilizers at 800 ppm. The inhibiting effect of ammonia solution I was also observed at 200 ppm except with F. oxysporum, while ammonia solution II stimulated the mycelial growth at 200 ppm. P. debaryanitfn and S. sclerotiorum were more susceptible to the tested liquid nitrogen fertilizers than R. solani and F. oxysporum.