In laboratory investigations, 9 methods of sorption ability against phosphorus in 36 soils of southern Poland (loam 7-71% , Corg 0.41-2.0%, Alox 14.7-64.8 mmol kg -1 and Feox 15.7-174.5 mmol kg-1) were compared. Evaluation of the maximum P sorption (Pmax) as well as two ways of buffering capacity against P (PBC) was estimated from multipoint curves according to the data of the Langmuir and Freundlich equation. The indices of P sorption obtained were compared with the single-point indices received by the addition to the soil of one P concentration (PSI1500, IPEC, and PRI200). All the indices of P sorption determined were highly correlated, being the evidence of the usability of the single-point indices in the evaluation of phosphorus sorption in routine soil tests. A significant correlation was found between the indices compared of Alox, Feox, loam concentration and CEC in the soil. The saturation of the soil with phosphorus, estimated by the Pox / (0.5(Feox + Alox ) was low and was in the range in 0.7-8.6 %.
Oak decline is insufficiently described problem. Declining oaks are in various age and the most commonly observed symptoms of the disease include growth inhibition and buds mortality. The dieback occurs periodically, mainly because of the impact of abiotic factors (drought, frost and the lowering of the groundwater level). In this complex phenomenon the biological factors, including numerous species of Chromista (Chromalveolata) and fungi play important role as well. The list of pathogens responsible for the dieback includes numerous species of Pythium and Phytophthora, as well as Biscogniauxia, Discula, Pleurophoma, Botryosphaeria and Diplodia. Among other organisms responsible for the oak decline are fungi belonging to Fusarium species. The aim of this study was to investigate the species composition of pathogens colonizing the dying oak buds including undeveloped or dying shoots obtained from Łomża, Rudka and Czarna Biało− stocka forest districts (eastern Poland). Sampling of symptomatic shoots of Quercus robur L. was performed in 2013, respecting different parts of tree crowns (top, central and bottom). Mycological material for analysis included mycelium growing on dying shoots after incubation in a chamber and tissue collected from symptomatic shoots and placed on PDA medium. For selected isolates of fungi the identification was confirmed by the PCR analysis using ITS1 and ITS4 primers. Among analyzed fungi Fusarium spp., Alternaria alternata, Cladosporium cladosporioides, Botryosphaeria quercuum and Coniothyrium spp. required special attention. The Fusarium spp. group of fungi dominated with an average frequency of 32%. The molecular analysis revealed the presence of several species including Fusarium avenaceum, Cladosporium cladosporioides, Lophiostoma corticola and Nectria mauritiicola.
Biosyntesis of fumonisin FB1, ergosterol content in kernels and rachis of artificially infected maize cobs was studied. The experiment was arranged in three factorial design (variety, strain, harvest time). Performed analysis revealed significant differences in fumonisin FB1 level depending on collection time. The level of mycotoxin was highly correlated with infection degree as well as with ergosterol content.
Based on two-year experiments on inoculated corn, including genotypes of sweet corn (Zea mays var. saccharata) and popcorn (Zea mays var. everta), the analysis of fumonisin FB1 content in kernels was performed. Infection degree of sweet corn was 2.00 and 2.13, which was distinctly stronger than infection of popcorn cobs (0.52 and 1.05). Despite of higher disease rating of Zea mays var. saccharata, the most dynamic increase in fumonisin FB1 biosythesis was observed in kernels of Zea mays var. everta. During the two cropping seasons, the mean level of FB1 in sweet corn ranged from 0.52 to 6.94 µg g–1, while in popcorn kernels from 0.96 to 28.49 µg g–1 in the 1st and 8th week after inoculation. Botanical varieties of maize as well as physiological state of kernels, determined by the water, amylose and starch contents, influenced on infection degree by Fusarium verticillioides and level of ear contamination by fumonisin FB1. Efficiency of biosynthesis of mentioned metabolites was inversely proportional to kernel water content.
Investigations were carried out in 2007–2009 on the plots of the Felin Experimental Station belonging to the University of Life Sciences in Lublin, Poland. The studies comprised two breeding lines of spelt wheat (Triticum aestivum ssp. spelta L. Thell.) – STH 3 and STH 715. Two levels of chemical protection were applied in the cultivation with minimal and complex protection. Infection of winter spelt wheat roots and stem bases was recorded in each growing season at hard dough stage (87 in Zadok’s scale). After 3 years of the study, the mean values of disease indexes for the analyzed spelt wheat lines in the experimental treatment with minimal protection were 28.53 and 40.30 respectively for STH 3 and STH 715. In the experimental combination with complex protection, after 3 years of the study the mean values of disease indexes ranged from 25.96 (STH 3) to 26.90 (STH 715). The mycological analysis showed that Fusarium spp., especially F. culmorum, caused root rot and necrosis of stem bases of spelt wheat in the experimental combination with minimal and complex protection. Moreover, Fusarium avenaceum and Bipolaris sorokiniana caused root rot and necrosis of stem bases of spelt wheat. Investigation carried out in a growth chamber on susceptibility of seedlings of three lines of spelt wheat (LO 2/09/n/2, LO 5/09/13/3, LO 5/09/5/4) to infection with Fusarium graminearum No. 8 and F. graminearum No. 45 showed that the genotypes did not differ in their susceptibility. All of them were susceptible, as indicated by high values of the disease indexes. No interaction was found between genotypes and strains of the fungus. This indicates the differential pathogenicity of Fusarium graminearum species.