Phytopathological aspect of onion seed production in organic farm

Celem przeprowadzonych badań, było określenie skuteczności stosowania biopreparatów (Biosept 33 SL, Biochikol 020 PC, i Bioczos BR) w zapobieganiu występowania mączniaka rzekomego cebuli (Peronospora destructor) i zdrowotności zebranych nasion. Doświadczenie polowe, w 4 powtórzeniach, przeprowadzono w gospodarstwie ekologicznym w Kiełpinie k/Tucholi. Stosowanie Bioseptu i Bochikolu istotnie zmniejszyło nasilenie choroby, zarówno na liściach cebuli w pierwszym roku uprawy jak i pędach przy uprawie na nasiona, podczas gdy Bioczos okazał się zupełnie nieskuteczny. Lepszy efekt uzyskano na poletkach opryskiwanych Bioseptem. Z nasion izolowano głównie Botrytis allii, Botrytis cinerea, Penicillium spp., j Alternaria alternata, Cladosporium herbarum. Z przeprowadzonych trzyletnich obserwacji wynika, że istnieje możliwość uprawy cebuli nasiennej w systemie ekologicznym.The objective of the research was to determine the efficiency of biopreparations (Biosept 33 SL, Biochikol 020 PC, Bioczos BR) in the prevention of the occurrence of downy mildew of onion (Peronospora destructor) and health of harvested seeds. Field experiment, in 4 replications, was conducted on the organic farm in Kiełpin near Tuchola. The use of Biosept andi Biochikol significantly reduced the severity of the disease, both on leaves (in the first year of cultivation) and seed stems, while Bioczos turned out to be completely ineffective. Better result was obtained for plots sprayed with Biosept. Seeds were settled mainly by Botrytis allii, Botrytis cinerea, Penicillium spp., Alternaria alternata and Cladosporium herbarum. Three-year observations suggest that there is a possibility of onion production under conditions of organic cropping system

Development of Sclerotinia sclerotiorum (Lib.) de Bary on stored carrot treated with Pythium oligandrum Drechsler determined by qPCR assay

Sclerotinia scletoriorum (Lib.) de Bary is a serious pathogen of carrots that can cause up to 50% losses of stored roots. Fungicides were found not to be completely effective for its control and due to residues they are not permitted for the use in storage. Biological control agents such as Pythium oligandrum may be a chance. The aim of research was to determine the level of carrot infection with S. sclerotiorum during few-month storage with qPCR and the potential control ability of this pathogen by Polyversum WP containing oospores of P. oligandrum. We analyzed carrot roots in combinations treated with Polyversum WP on the field, fumigated with biopreparation before storage and untreated control. S. sclerotiorum developed on carrots treated and untreated with Polyversum WP. During the storage, pathogen was isolated from 44.4% samples and P. oligandrum from 53.8% ones, respectively in the range from 0.0001 to 130 200.0; pg and from 0.004 to 0.3440 pg per sample. The number of roots with S. sclerotiorum and degree of their infection increased with prolonged storage. Analyses suggest that Polyversum WP may potentially limit the growth of S. sclerotiorum