Effects of winter green manuring on organic cucumber production in unheated greenhouse conditions

WOS: 000321226800008The effects of winter green manure crops on organic cucumber production were determined in unheated greenhouse conditions in order to integrate soil building and conservation practices, which are critically important in greenhouse production without crop rotation. The study was conducted between 2006 and 2008 to compare (1) pea (Pisum sativum L.), (2) Italian rye-grass (Lolium multiflorum L.), and (3) common vetch (Vicia sativa L.) as winter green manure plants. These treatments were compared with a control without green manuring (4). All of the plots were divided into halves, and poultry manure was applied as 0 (-PM) and 0.75 kg m(-2) (+PM) to each. Cucumber (Cucumis sativus 'Sardes') was grown as a spring cycle production after winter green manure plants were incorporated into the soil. Treatments were evaluated in terms of yield, fruit quality parameters such as electrical conductivity, pH, titratable acidity, total soluble solids, and dry weight. Soil fertility and pest/disease incidence were also determined. It was found that cucumber yield varied between 9.7 and 16.3 kg m(-2) and between 10.0 and 13.6 kg m(-2) in the first and second spring growing seasons, respectively. Green manuring improved the organic matter and nitrogen contents of the soils. Other available nutrients in the soil were also analyzed and found to be sufficient. Additionally, the nutrient status of the cucumber plants was found to be sufficient. Pea and vetch proved to be efficient as winter green manure crops for vegetable production in greenhouses. Poultry manure also produced positive effects, in particular on soil total N content. Therefore, it could be used with green manure crops according to the N content of the soil.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [1050571]This project (1050571) was supported by the Scientific and Technological Research Council of Turkey (TUBITAK). The author is grateful to Dr Ken Cockshull for his helpful comments

Red blood cell susceptibility to pneumolysin: Correlation with membrane biochemical and physical properties

This study investigated the effect of the biochemical and biophysical properties of the plasma membrane as well as membrane morphology on the susceptibility of human red blood cells to the cholesterol-dependent cytolysin pneumolysin, a key virulence factor of Streptococcus pneumoniae, using single cell studies. We show a correlation between the physical properties of the membrane (bending rigidity, surface and dipole electrostatic potentials) and the susceptibility of red blood cells to pneumolysin-induced haemolysis. We demonstrate that biochemical modifications of the membrane induced by oxidative stress, lipid scrambling and artificial cell aging modulate the cell response to the toxin. We provide evidence that the diversity of response to pneumolysin in diabetic red blood cells correlates with levels of glycated haemoglobin (Hba1c) and that the mechanical properties of the red blood cell plasma membrane are altered in diabetes. Finally, we show that diabetic red blood cells are more resistant to pneumolysin and the related toxin perfringolysin O relative to healthy red blood cells. Taken together, these studies indicate that the diversity of cell response to pneumolysin within a population of human red blood cells is influenced by the biophysical and biochemical status of the plasma membrane and the chemical and/or oxidative stress prehistory of the cell