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  • Effect of M9, MM106 and Seedling Rootstocks on Sunburn-Sensitivity of 33 Apple Cultivars, and Sunburn Effects on Fruit Quality
    236-247
    Views:
    98

    The purpose of this study was to investigate the sunburn-sensitivity of 33 apple cultivars grafted onto 3 rootstocks (M9, MM106 and seedling) in a commercial orchard at Nagykutas (in the western part of Hungary). The authors also searched for any relationship between fruit quality parameters and the frequency of sunburn on the fruit surface.
    During the observations, the cultivars had rootstock-specific properties in respect to sunburn-susceptibility. Accordingly, the injury decreased in the order M9, MM106 and seedling rootstocks. The differences in the sensitivity were founded on the foliage-morphological characteristics of trees, caused by the growing vigour of the rootstocks. Accordingly, the highest value of sunburn injury was observed on M9 rootstock, because this rootstock has a dwarfing effect on the grafted main cultivars. Thus, the vegetative area of these trees grew very slowly and the foliage was not compact enough to protect the fruits from the strong rays. The largeness and density of the foliage increased in the order M9, MM106 and seedling rootstocks. Relationships were also demonstrated between the diameter of the upper part of crown, the size of leaves, the number of fruits per tree and the injury from sunburn.
    The damage values showed, that the gravity of symptoms did not decrease below a well-defined level of dimension on fruit. Determined potential area of injury was necessary for the symptoms to become visible.
    The authors categorized the cultivars in the respect of values of sunburn frequency: I. „Not sensitive”, II. „Moderately sensitive” and III. „Very sensitive” categories were constituted. Generally, the Gala cultivars showed low damage (or were free of symptoms), in contrast, Golden mutants suffered relative strongly. The most sensitive cultivar was Jonica on all three of rootstocks.
    We searched for any relationship between the fruit quality parameters and the frequency of sunburn. A significant correlation was found in the cases of fruit weight and colour-coverage. The latter can be related to that fact that highly colour covered fruits are found on the peripherial part of crown, so these are exposed to stronger sun rays

  • The Effect of Sunburn on Fruit Quality of cv. Idared Apple
    23-31
    Views:
    114

    The aim of this study is to investigate the effect of sunburn injury on fruit quality parameters (colour-coverage, depth of affected tissue, fruit flesh firmness, soluble solids content) of apple.
    The symptoms of sunburn injury appeared in concentric ring shape, differed from each other and surface colour-coverage. This can be due to the ratio of the injury. The authors observed the following colours on the fruit surface (from the epicentre of the blotch on the transversal diameter of the fruit) dark brown (strongly affected), light brown (moderately affected), pale red transition (poorly affected), red surface colour-coverage (not affected).
    Sunburn of apple fruits is a surface injury caused by solar radiation, heat and low air relative humidity that in the initial phase results in a light corky layer, golden or bronze discolouration, and injuries to the epidermal tissue, in the surface exposed to radiation. Thus it detracts from its appearance, but in most cases, it would not cause serious damage to the epidermal tissue. The depth of affected tissue is not considerable, its values are between 1.5-2.0 mm generally. It is commonly known that the tissue structure of apple fruit is not homogeneous. Accordingly, the degree of injury shows some differences under the different parts of the fruit surface.
    On the basis of flesh firmness research, the authors established that the measure of flesh firmness of the affected part of apple fruit increases with the effect of sunburn. The consequence of this is the suffered plant cells will die, the water content of this tissue decreases and the fruit gets harder. This water-loss caused the increase of soluble solids content.

  • The effect of sunburn damage on the fruit quality parameters of apple (Malus domestica cv. Idared)
    55-64
    Views:
    178

    In the present study the authors investigated the effect of sunburn injury on fruit quality parameters (cover colour, depth of tissue damage, fruit flesh firmness, dry matter content) of apple.
    The symptoms of sunburn injury appeared as concentric rings, differing in colour from each other and the cover colour. This can be connected with the ratio of the injury. The authors observed the following colours on the fruit surface (from the epicentre of spots on the surface of the fruit) dark brown (strongly damaged), light brown (moderately damaged), pale red transition (weakly damaged), red surface cover colour (not damaged).
    Sunburn of apple fruits is a surface injury caused by solar radiation, heat and low relative humidity. In the initial phase, a light corky layer, golden or bronze discolouration and injuries of the epidermal tissue appear on the surface exposed to radiation. Thus, it detracts from the fruit’s appearance, but in most of the cases it would not cause serious damages in the epidermal tissue. The depth of tissue damage is not considerable, its values are between 1.5-2.0 mm in general. It is commonly known, that tissue structure of the apple fruit is not homogeneous. Accordingly, the degree of injury shows some differences under the different parts of the fruit surface.
    On the basis of the flesh firmness studies, it can be stated that the flesh firmness of the damaged parts increases due to the sunburn effect. This is due to the fact that the damaged plant cells die, the water content of the tissue decreases and it hardens. However, due to this reduction in the water content the dry matter content will increase.

  • Practical experiences of a designing and operating a pilot aquaponic system
    27-32
    Views:
    335

    Aquaponics is the combination of fish farming (aquaculture) and the soilless cultivation of plants (hydroponics). The aquaponics system is an artificial, recirculating ecosystem, in which bacterial processes convert the waste materials in the water used for fish rearing into plant nutrients, and therefore with the generated heat it is suitable for culturing economically valuable plants, and thus it mitigates the nutrient laden and quantity of the intensive fish producing systems’ effluent water.

    The primary goal of our 12 separate unit’s aquaponics system was to gain experience. We would like to find the right plant species, which are fit for that medium, and their crop can be sold. Besides the plants, our attention focused on the fish. Two fish species were included in the experiments, the common carp and barramundi. It was difficult to create them a perfect living space, besides a constantly changing conditions temperature. Apart the above mentioned we had a problem with the number of individuals per tank, the deformity of the fish body and the too high volume of pH (we registered continuous values above 8.4). We get by carps 4.7 grams of weight gain during 15 weeks, because of the bad conditions.

    The main problems at the plants are caused by aphesis and protection against sunburn. Even so we have got the multiples of field yields for each plant species. At salad has grown twice of field yields, tomatoes one and half, kohlrabi than 3.5 times more. The causes of multiple yields are the continuous balanced water and the nutrient uptake of plants. Each plant species fit for cultivating in aquaponics and their crops are delicious, chemical -free, safe and marketable. The plants should be more concentrated. After the experiment, it has been determinated that the carp is suitable for aquaponics, but greater weight gain could be achieved with optimal selection of size of rearing units.