K. Demir

Ankara University, Ankara, Ankara, Turkey

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Publications (3)3.01 Total impact

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    Y Okay, K Demir
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    ABSTRACT: Centaurea tchihatcheffii Fisch. and Mey., is a critically endangered endemic species, which grows on limited area around Golbasi district of Ankara province. It has attractive pink, red, purple flowers, the colours of which change with maturation. It has a high potential as out door ornamental plant and as cut flower. Its natural habitat is continuously on decrease because of uncontrolled plucking, intense construction activities and urbanization. The most important reason why the generation of the species is endangered is strong anthropogenic pressure. Therefore, the protection of this plant is of great importance. Study of propagation possibilities for the protection of this species, is of primary importance. This paper reviews C. tchihatcheffii, propagation studies.
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    ABSTRACT: Poultry manure (PM) must be disposed of from poultry farms, but is a potentially valuable source of macro- and micronutrients for plant growth. The objective of this study was to examine the effects of poultry manure on the growth of tomato (Lycopersicon esculentum) plants. Yields of fruits and vegetative material of plants grown in soil with 0, 10, 20 and 40gkg−1 PM added were measured. Concentrations of N, P, K, Ca, Mg, S, Fe, Zn, Cu, Mn, Mo, Cl, Si, Br, Rb, Sr and Ba in leaves at flowering and at final harvest and in fruits were determined by polarized energy dispersive X-ray fluorescence (PEDXRF). Poultry manure fertilization improved tomato shoot growth and also fruit yield and increased leaf N concentrations at the harvest stage. In addition, P concentrations of the leaves and fruits were increased as the application rate of PM was increased. Fruit Ca and Mg were significantly reduced by increased rate of PM application, but not to the extent to cause the calcium deficiency disorder blossom end rot. Applied high levels of PM slightly increased the concentrations of leaf Mo and Br at the harvest stage. Poultry manure applications had a positive effect on the concentrations of leaf Zn, Cu, Cl and Rb at both sampling stages, but leaf Si concentration was reduced by PM treatments. The concentrations of Zn and Rb were increased in the fruits by PM treatments, but the concentrations of Br were decreased. Applied PM levels had no significant effects on the concentrations of K, S, Fe, Sr or Ba in tomato plants. It is concluded that the increased fruit yield, and the increased concentration of Zn (an element required in the human diet) and the lowered concentration of potentially harmful Br in the fruit make poultry manure a valuable growing medium for tomato production.
    Scientia Horticulturae 11/2010; 127(1):16-22. DOI:10.1016/j.scienta.2010.08.009 · 1.50 Impact Factor
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    ABSTRACT: We investigated individual and combined effects of B toxicity and salinity in the presence or absence of silicon on the shoot growth, concentrations of sodium (Na), chloride (Cl), boron (B) and silicon (Si), and stomatal resistance (SR), lipid peroxidation (MDA), proline accumulation, H2O2 accumulation and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) activity grapevine rootstocks of 41B (V. Vinifera × V. Berlandieri) and 1103P (V. Berlandieri × V. Rupestris). Applied Si counteracted the deleterious effects of salinity and boron toxicity on shoot growth by lowering the accumulation of Na in 1103P, and B and Cl in the both rootstocks. Stomatal resistance, MDA, and the concentrations of H2O2 and proline were higher in the plants grown in conditions of B toxicity, salinity and their combination while applied Si lowered these parameters. Lowering SOD and CAT but increasing APX, Si treatment significantly affected the enzyme activities of both rootstocks. Based on the present work, it can be concluded that Si alleviates the adverse effects of salinity, B toxicity and combined salinity-B toxicity on grapevine rootstocks by preventing both oxidative membrane damage and translocation of Na and B from root to shoots and/or soil to plant, and also lowering the phytotoxic effects of Na and B within plant tissues. When considering the antioxidative response and membrane systems, it was concluded that the rootstock 1103P was responsive to Si under stress conditions. To our knowledge, this is the first report that Si improves the combined salt and B tolerance of grapevine grown under saline, B toxic, and B toxic and saline conditions which describes membrane related parameters and antioxidant responses.
    Scientia Horticulturae 12/2009; 123(2-123):240-246. DOI:10.1016/j.scienta.2009.09.005 · 1.50 Impact Factor