Ribes

Abstract: The focus of our study was to investigate the effect of crop load on the accumulation and composition of primary metabolites (sugars and organic acids), selected groups of flavonoids (anthocyanins ...

Abstract: Accurate and nondestructive methods to determine individual leaf areas of plants are a useful tool in physiological and agronomic research. Determining the individual leaf area (LA) of small fruit like raspberry (Rubus idaeus L.), redcurrant (Ribes rubrum L.), blackberry (Rubus fruticosus L.), gooseberry (Ribes grossularia L.), and highbush blueberry (Vaccinium corymbosum L.) involves measurements of leaf parameters such as length (L) and width (W) or some combinations of these parameters. A 2-year investigation was carried out during 2006 (on seven raspberry, seven red- currant, six blackberry, five gooseberry, and two highbush blueberry cultivars) and 2007 (on one cultivar per species) under open field conditions to test whether a model could be developed to estimate LA of small fruits across cultivars. Regression analysis of LA versus L and W revealed several models that could be used for estimating the area of individual small fruit leaves. A linear model having LW as the independent variable provided the most accurate estimate (highest R 2 , smallest mean square error, and the smallest predicted residual error sum of squares) of LA in all small fruit berries. Validation of the model having LW of leaves measured in the 2007 experiment coming from other cultivars of small fruit berries showed that the correlation between calculated and measured small fruit berries LAs was very high. Therefore, these models can estimate accurately and in large quantities the LA of small fruit plants in many experimental comparisons without the use of any expensive instruments.

Abstract: Due to high cost, toxicity of conventional inhibitors and environmental regulations, corrosion scientists have directed toward plant extracts as alternatives to conventional inhibitors. In this study, leaf extracts of Rheum ribes (RR leaf) were prepared, and their adsorption and protective effects on mild steel (MS) corrosion were investigated in 1.0 M HCl solution. The synergistic inhibition effect of iodide ions and the stability of surface inhibitor film were also studied. The protection ability of extract was investigated using electrochemical techniques. The stability of surface film was evaluated by potentiodynamic and potentiostatic studies. After being exposed to the corrosive medium, the surface of metal was examined using SEM, EDX, AFM and contact angle measurements. The extract molecules formed an adherent and homogenous protective film on the MS surface. When the RR leaf extract concentration increased, a stronger inhibition effect against corrosive attack was obtained. At 1000 ppm extract concentration, the protection efficiency of RR leaf extract increased from 91.8% to 94.9% when 1000 ppm KI was added to the inhibited acid solution. The extract molecules adsorbed to the metal surface via physical and chemical interactions. The surface extract film was very stable under potentiostatic or potentiodynamic conditions.