The determination of soil fungistasis for black mould disease in onion production areas of Tekirdağ province

Bu arastırmada Tekirdag ili ve ilçelerinde bulunan yemeklik sogan (Allium cepa L.) tarlalarından alınan 27 toprak örneginin, soganda Aspergillus niger V. Tieghem tarafından olusturulan siyah küf hastalıgına karsı fungistasisi incelenmistir. Toprak örnekleri fide döneminde rizosfer bölgesinde 2-20 cm derinlikten alınmıs, fiziksel ve kimyasal karakteristikleri belirlenmistir. Fungistasis iki yöntemle incelenmistir. Bunlardan birincisi topraktaki uçucu bilesiklerin patojen fungusun spor çimlenmesini engellemesinin belirlenmesi, digeri ise toprak örneklerindeki antagonist fungus populasyonunun tespiti olmustur. ncelenen toprak örneklerinden sekiz tanesi A. niger 'e karsı uçucu bilesikler yoluyla fungistasise neden olmustur. Bununla birlikte topraktaki uçucu bilesiklerin patojenin spor çimlenmesini engelleme oranları ile topragın fizikokimyasal yapısı arasında bir korelasyon saptanmamıstır. Bes toprak örneginde fungistasis antagonist funguslarla saglanmıs, altı toprak örnegi ise her iki fungistasis mekanizmasını göstermistir.The fungistasis property against black mould of onion caused by Aspergillus niger V. Tieghem of 27 soil samples, which were collected from onion (Allium cepa L.) growing areas of Tekirdag province and its surrounding, has been tested in this research. Soil samples were taken from rhizosphere region at a depth of 2–20 cm. at seedling stage and their some physical and chemical properties were determined. Fungistasis were evaluated using two methods. One method involved the inhibition of pathogen spore germination by the volatile compounds from soil, and the other the determination of fungal population content of the soil samples. Six of the soil showed only soil volatile fungistasis against Aspergillus niger. However, the inhibition rates of volatile compounds from soils for the inhibition of spore germination of pathogen were not correlated with physicochemical properties of the soils. Antagonist fungi managed fungistasis in three soil samples. Six of the soils included both fungistasis mechanisms