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The reported study describes the separation of humic substances (HS) dissolved in surface waters into hydrophilic and hydrophobic fractions with the SPE method onto StrataX (Phenomenex) columns. The separated fractions were analyzed with the HPLC-C18 (Merck column) method for relative polarity of humic (HA) and fulvic (FA) acids in the samples. Analyses were carried out on samples collected from 7 lakes constituting two cascade systems located in the same catchment of the Ełk River. During HPLC assays, an effect of size exclusion (SE) was observed, especially for the hydrophilic fraction. The HPLC analyses enabled us to demonstrate that in both hydrological systems the hydrophilic fraction contained mainly molecules with molecular weights exceeding 1,000Da and of practically equal relative polarity. Only in system II (five lakes) was the hydrophobic fraction strongly diversified quantitatively as well as in terms of molecular weight and polarity between the samples. Results of analysis show that this system was subject to a strong anthropogenic impact.
The investigations were carried out in 2001-2003 at the Horticulture Experimental Station, University of Agriculture in Szczecin. The influence of truss cutting and application of Ethrel preparation on the flowering and acceleration of ripening of small-sized tomato fruit was studied. The experiment focused on the following factors: methods of acceleration of tomato fruit ripening (truss cutting, Ethrel preparation, truss cutting + Ethrel preparation) and tomato cultivars ('Cheresita F1', 'Favorita F1'). The applied methods had no influence on the number of flowers and germs of the small-sized tomato. The truss cutting increased the percentage of set fruits compared to the number of flowers. The application of Ethrel preparation along with truss cutting significantly increased the early yield of tomato fruits. The Ethrel and truss cutting accelerated the small-sized tomato harvesting by 12 days. Cv. 'Cheresita F1' produced a larger number of flowers, germs and fruits than 'Favorita F1'.
The present study, carried out in the period 2007-2009 in the Sandomierz Upland, did not show a significant effect of foliar fertilization on trunk thickness and canopy volume in the cultivar Łutówka. However, under the influence of urea applied three times in combination with Florovit at a concentration of 0.5%, a clear increasing trend was observed in the above mentioned parameters used to assess the strength of growth. In years of abundant fruiting, this study showed a significant increase, or on the verge of significance, in yield after threefold application of urea and Florovit in combination. A small insignificant effect of fertilization on fruit weight shows that the growth in yield after the application of fertilization was produced as a consequential effect of a significant increase in the length of one-year shoots and thereby in flowering intensity of the ‘Łutówka’ cherry trees. In the case of the sour cherry cultivar Łutówka bearing fruit on one-year shoots, foliar feeding after flowering using multi-nutrient fertilizers and urea can be recommended as a technological treatment, in particular in years of abundant fruiting.
The studies performed in 1997 - 1999 have shown that herbicides such as Azotop 50 (simazine, 6-chloro-N, N-diethyl-l,3,5-triazine-2,4-diamine) in the dose 1 kg ha- 1 or Afalon 50 WP (linuron, N'-(3,4-dichlorophenyl)N-methoxy-N-methylurea) in dose 1.5 kg ha-1 or its mixture with Dual 960 EC (metolachlor, 2-chloro- N(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl) acetamide) in dose 1.5 1 ha-1 applied in early spring significantly decreased number of weeds in nursery of sour cherry trees cv. Lutówka budded on Prunus mahaleb L rootstocks as compared with mechanical weed control. Both, Azotop 50 and Azotop 50 in mixture with Dual 960 EC eliminated weeds for the longer period than Afalon 50 WP and Afalon 50 WP with Dual 960 EC. Herbicides did not affect tree trunk diameter (at 30 cm. from the ground level), the number and total length of shoots of one-year-old sour cherry trees in comparison with mechanical control of weeds.
The results obtained in this study shown that depth of planting significantly affected the yield. The trees planted of the place of budding 7 cm under the ground gave about twice lower yield per tree and hectar and growth the more stranger than others planted upper. Depth of planting had no significantly effect on fruit quality. Fruit mass and percent of fruits with upper 75% of coloured surface were more (significantly) influnced by weather conditions in different years.
W latach 2004-2007 w szkółce produkcyjnej przebadano wpływ trzech różnych terminów formowania pni o wysokości 50 cm na wzrost drzewek wiśni odmiany ‘Łutówka’. Zastosowane sposoby formowania pni nie wpływały istotnie na średnicę pni na wysokości 30 cm, wysokość okulantów oraz długość i liczbę pędów w koronie. Trzykrotne usuwanie zielnych pędów syleptycznych powodowało istotne zwiększanie masy liścia w porównaniu do jednorazowego późnego zabiegu. W oparciu o uzyskane wyniki badań w przypadku odmiany ‘Łutówka’ należy polecać do praktyki częste pensowanie zielnych pędów rozpoczynane w okresie utworzenia pierwszych 5-6 pędów syleptycznych. Ten sposób formowania pni jest łatwy w wykonaniu, a pozostawione po pędach zielnych 1-2-centymetrowe czopki żółkną i opadają dając zupełnie gładki pień.
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