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  • First evaluation of fruit quality of some new and old sour cherry cultivars in Hungarian climatic condition
    37-43.
    Views:
    249

    Indeed, in the last decade a large number of new sour cherry cultivars with new notable flavor characteristics have been released. There is no enough information related to qualitative characteristics which consistently segregated based on their predominant sensory characteristics. The present study carried out at tow consecutive years (2008 and 2009) and examined some qualitative characters which are the main importance in the specialty cherries trade, The main objective was to determine fruits quality of Érdi bőtermő, Oblacsinszka, Debreceni bőtermő, Csengődi, Pándy 279, Éva, Kántorjánosi, Újfehértói fürtös and Petri sour cherry cultivars. Changes observed in major characteristics such as fruit detachment force, width, length, weight, peduncle length, flesh firmness, brix, citric acid, Suger/acid ratio and pit weigh.While observed no change in flesh/pit ratio and Coordinate of colour (X*, y*, x*), hue angle and chroma value, in different years. In all measured factors, there was significant difference between selected cultivars of sour cherry fruit. Debreceni bőtermő showed higher values of fruit detachment force in 2008, while had the lover of fruit detachment force in 2009. Fruit firmness of “Érdi bőtermő” were monitored at lover value in both 2-year.

  • Some physical properties of sweet cherries
    63-70.
    Views:
    170

    The determination of the optimal time of the mechanical harvesting of sweet cherries has a great importance not only to prevent the fruit from mechanical injury but to find the optimal setting parameters of the harvesting machine. The primary objective of the experiments was to determine the force and work required to detach the stem from the limb and the fruit from the stem. Furthermore to measure the three main sizes (width, height, thickness) of the fruits in order to determine the sphericity, and also the pulp-stone ratio by measuring the mass of the fruit with the stone and then the mass of the stone. The average sizes of the fruits: width 19.62–27.76 mm, height 17.83–24.54 mm and thickness 17.30–23.60 mm. The stem length varied between 28.69 mm and 55.80 mm. The sphericity of each variety was above 90%. The average mass varied between 3.63 and 9.68 g. The stone mass turned to be between 0.27 g and 0.42 g. The stone-pulp ratio varied between 3.7%and 7.7%. The average pulp mass varied between 3.35 g and 9.32 g. The average values of maximum loads required to detach the sweet cherries from the stem varied between 3.23 N and, 4.12 N. The force required to detach the stem from the limb was 50–90% higher than the force needed to tear the fruit from the stem.

  • Modelling and comparing two canopy shapes using FEM
    71-74.
    Views:
    112

    Central leader and Vase form canopy models were built using FEM. Their main characteristics were chosen to be the same. The models were virtually exposed to the effect of steady-state horizontal forced vibration in the frequency range of 0-20 Hz. Acceleration-frequency curves were calculated and drawn to find the best frequency values for the effective detachment and also to see the acceleration differences in the limbs. For the same purpose the direction of shaking was also changed. It was found that for the Central leader canopy shape multidirectional shaking would bring uniform detachment while for the Vase form trees also the unidirectional shakers were appropriate. The acceleration achieved for the Vase form models were much higher than for the Central leader type. The acceleration-frequency curve of the shaker unit can be used to find the best frequency for shaking.

  • A simple model for fruit tree shaking harvest
    33-36.
    Views:
    195

    A tree structure model was composed of trunk and main roots. It included a mass, spring and damping element, all of them reduced to the external end of the main roots. The model parameters, such as virtual turning centre, reduced mass, spring constant and clamping coefficient were measured on a real cherry tree. The model was than virtually shaken at 80 cm trunk height and acceleration and displacement amplitudes versus shaking frequency were calculated. The real cherry tree was shaken also at 80 cm trunk height by an inertia type shaker machine and the same data were recorded. The acceleration amplitude vs. frequency and displacement amplitude vs. frequency functions were similar for the virtual and real tree which proves the ability of the model. Power demand and specific power demand was then calculated in function of shaking frequency. The diagrams show that the shaking frequency of 12-14 Hz, of the practice is not the most efficient concerning amplitude, but is probably necessary from the point of view of acceleration needed to detachment of fruits.