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Detemination of the time of pruning regarding the ability of developing flower buds and their frost tolerance in sweet cherry varieties
45-48.Views:349In sweet cherry growing, intense technology is introduced as the up to date development. Among the elements of the technology are the choice of variety, planting design and pruning are the main elements. The methods, intensity and the timing of pruning are largely dependent from the growing habits of the varieties, the light demand of the parts of different age and their tendency of getting bald on the aging zones. One of the main limiting factors of production, the frost damages are outstanding. In choosing the site of plantation, we must avoid the places, where spring frosts used to occur, the next moment is the role of the variety and the technology applied. In Hungary, the late or spring frosts are considered, however, the winter frosts may also cause heavy losses, which depend also on the health and nutritional condition of the trees when being exposed to temperature minima. Our present study is based on a 9-year-old plantation trained to slender spindle as well as to free spindle crown. We observed the development of fruiting structures and their frost damage also in relation with the timing of the pruning operations during the winter or summer, and compared also the varieties with each other.
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Anatomical study of the leaves and petioles of scab resistant and susceptible apple cultivars
53-57.Views:401Anatomic studies have been performed on the leaf blade, petiole and annual shoot on six apple cultivars by means of scanning electron as well as light microscope. Four of the cultivars examined are resistant to scab (Florina, Freedom, MR-10, MR-11), whereas two of them are susceptible (Jonathan and Idared). Preliminary results suggest that differences in the width of cross sections of leaf blades, in hairyness, in the shape and size of epidermal cells, moreover, in the cross sections of petioles and shoots are considerable. Some of the anatomical properties seem to be correlated with scab resistance or susceptility of the respective cultivars. Therefore, further studies extending to other cultivars may corroborate our claims to find causal relations between anatomical traits of the leaves and disease, especially scab resistance of apple cultivars.
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Training systems of fruit trees in Hungary
123-127.Views:1483Growing sites and soil conditions of Hungary warrant profitable production of several temperate fruits at elevated levels of quality. The climate of the Carpathian basin is a mixtures of three main climatic zones the prevalence of which may change seasonally: Atlantic, continental and Mediterranean, therefore, growing sites are rather various. Temperature minima of the winter and late spring frosts are the main elements of risk. In choice of the system of cultivation, regularity of yields and intensity are to be observed equally. Regular yields are particularly aimed in stone fruit cultures.
For apple and pear plantations of high density required for intense production are promoted favourably. Accessories of intense orchards (irrigation, supporting system, rootstocks, phytotechniques, etc.) are important. In peach and plum trees are trained to funnel-shape crowns, in general, intense-types are possible in plum, only. In apricots, a Hungarian speciality, the "umbrella" type of crown is applied, almost exclusively, according to Papp. In sweet and sour cherry, the harvest technique, manual or mechanised, according to the intended utilisation, are determining the form of training.
Red and black currants as small fruits are grown mostly as bushes or hedgerows without any supporting system designed to facilitate mechanical harvest. Raspberries and blackberries are grown as hedges on trellis. Gooseberry is a special case, being a low, thorny bush difficult to be picked. Thus grafted small trees are attached to a wire-trellis which helps to solve problems of plant protection too.
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Preliminary studies on propagating natural mason bee (mixed Osmia cornuta and O. rufa) populations in artificial nesting media at the site for fruit orchard pollination
95-101.Views:579Preliminary field management studies were made to increase the population density of native early spring Osmia species (O. cornuta, O. rufa) at fruit tree plantations in Hungary. Initial bee activity around artificial nesting media and the population increase during consecutive years were much smaller at large commercial fruit orchards under intense chemical plant protection than in small mixed fruit plantation with moderate or low pesticide usage. Osmias accepted all the four kinds of tested artificial nesting media (reed, bamboo rods, hardwood blocks and light walling blocks with drilled holes). Reed provided the best nesting conditions so it is suggested to be used in the practice. Calculations showed that under favourable conditions more than 50 to 100 thousand incoming flights (arrivals or landings) occurred in a single day around a single bee shelter and this makes enormous number of possible bee visits at fruit tree flowers. For this reason it is strongly recommended to put simple bee shelters filled with artificial nesting media into fruit orchards. Experiences show that the population sizes of Osmias increase during consecutive years without any specific additional maintenance except providing shelters and nesting media.
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Characterization of sunburn damage to apple fruits and leaves
15-20.Views:1967The specific conditions of the formation of three different types of sunburn (sunburn browning, sunburn necrosis, and photooxidative sunburn) have been recently characterized on apple fruit. However, no information is still available on leaf damage. Therefore, the aims of this study were i) to extend the knowledge on fruit damage, ii) characterize leaf damage and iii) find relationship between fruit and leaf damage. The observations were made on 586 apple accessions in a gene bank orchard located in Hungary. The incidence of the three different types of fruit symptoms were recorded and based on the visual symptoms, two different types of leaf sunburn (sunburn yellowing and sunburn necrosis) were characterized. The most frequent type of fruit sunburn observed was sunburn browning. Photooxidative sunburn was found for less number of accessions, and only some accessions were affected by sunburn necrosis. Fruit were far more susceptible than leaves; (>60%) of the examined accessions were affected by fruit damage and (<3%) by leaf damage. Although a large number of accessions were affected, the percentage of fruit damaged within accessions was not that excessive; ~6% of the fruit assessed showed the symptoms of sunburn browning. Significantly fewer fruit were damaged by sunburn necrosis (~1%) or photooxidative sunburn (~1.4%) than sunburn browning. The percentage of leaves damaged within accessions were simlarly very low (~1%). Close relationship between fruit and leaf damage was found. Accesions with relatively heavily sunburned leaves usually had severe fruit damage as well. Leaves showing sunburn symptoms were usually closely located around those fruit which were sunburned severely. Leaf damage of sunburn was found on spur leaves in a great majority of the accessions damaged, shoot leaves did not seem to be susceptible to sunburn.
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Inheritance of fruit colour and of shoot's pigmentation in the case of interspecific raspberry hybrids
33-36.Views:229In our research, fruit colour and the shoot's red pigmentation were evaluated in the hybrids of Rubus idaeus and Rubus parvifolius crossings. Y and Ys genes beside the T genes determine the fruit colour of interspecific hybrids, which is characteristic for raspberry. For the explanation of the significantly higher results of segregation then expected at the yellow fruit colour hybrids, we have supposed the presence of a second yellow gene (Y2). In the yellow colour, a lot of different shade colours can be identified from light yellow to the apricot colour. In the regulation of the production of yellow and red colour, several other genes can participate also. Identification of these genes would require more additional research. The C gene determines the shoot colour of raspberry and in the case of wild raspberries we have revealed the role of a dominant Pr gene. The Y and Pr genes are descended linked. The value of crossing over is approximately 15%. The anthocyanin production inhibitory effect of the Y gene extends only for fruit. At the shoots of yellow fruit plants, strong anthocyanin production was observed.
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Preliminary results of renewal pruning an 18 years old sour cherry trees
41-42.Views:334Sour cherry is a light demanding fruit species. As most of the crop is developing from buds on one year old shoots and 2-yearold wood, the formation of bare wood can be seen apparently in a badly maintained canopy. The formation of „whip shoots” indicates the degree of bare wood. Unfortunately in many gardens and commercial orchards sour cherry trees resemble willow trees. Owners often decide to grub old orchards, although the useful cropping lifespan of the trees planted in a correct spacing can be 20-30 years on a move vigorous rootstock. Therefore renewal pruning can contribute to the full renewal of the orchard, but the length of its effect is depending on the growth characteristics and renewal capabilities of the cultivar. The growth characteristics of the cultivars are different. The regeneration capabilities of different aged wood are also different. These differences emphasize the need for cultivar specifi c pruning. Knowing the reactions to renewal pruning, we can ensure regular high crops with excellent quality by applying cultivar specifi c rotation pruning.
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Study on the mushroom species Agaricus blazei (Murill)
45-48.Views:388Nowadays, Agaricus blazei is known all over the world as a mushroom species with unparalleled medicinal properties besides its culinary delights and therefore its regular consumption is recommended in the first place for the prevention of various cancers. For the past decade researchers have been active in the study of its therapeutic properties. Its production started only a decade ago and there are a number of questions yet to be answered. At the moment, the most widespread technique is to grow it using composts similar to those of the button mushroom. In contrast to the common button mushroom, its production differs markedly from that of the button mushroom in that it develops fruiting bodies only in light and requires that the compost temperature be high, around 25 °C, also in the fruiting period and has a much higher need for fresh air. It is also sold in fresh form but mainly as a dried product, in powdered form or as capsules or pills.
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Stimulating effect of distilled water
47-49.Views:396It is an early observation that plants in poor soil are developing roots quicker and more abundantly than on rich one. There is a similar correlation between the nutrient status of medium and adventitious root formation.
In order to throw more light on the background of this strange phenomenon we started a systematic experimental program in which the biological effects of distilled water as model factor was investigated.
The experiments proved that the root formation of Pinto bean (Phaseolus vulgaris L.) cuttings with 3 cm long hypocotyls was promoted by distilled water.
The phenomenon above accompanied with slower decline and faster recovery of total and also water-soluble protein content, more intensive efflux of amino acids, greater amount of tryptophane and increased uptake of water compared to those in control hypocotyls. From other data obtained we may suspect that some additional active substance unknown for us also contributes to the stimulation of root initiation in distilled water.
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Sunburn assessment: A critical appraisal of methods and techniques for characterizing the damage to apple fruit
7-14.Views:857Many methods and techniques have been introduced for measuring alterations in the fruit and in its surrounding environment related to sunburn incidence. The research objectives, fruit materials and the environment to be evaluated dictate the methods to follow. These procedures are either non-destructive and involve techniques that allow us to track the course of sunburn development and related environmental parameters, or destructive and involve the removal of fruit from the tree for field/laboratory measurements. Techniques employed can be used for pre-symptomatic monitoring (before symptoms become visible) or characterizing the symptoms already present. The principles behind the measurements and their usefulness for sunburn assessments are discussed and critically evaluated in this review paper. Descriptions and evaluations of the methods and techniques were made in the following groups: 1. Thermal measurements; 2. Visual assessments; 3. Fruit quality measurements; 4. Measurements of physiological and biochemical alterations; and 5. Practical evaluation of sunburn damage. Thermal measurements involve methods tracking the ambient temperature and fruit surface temperature, and their relation to sunburn formation. Visual assessments cover all measuring techniques (skin color, chlorophyll fluorescence, radiation reflection, electron microscopy) that are able to detect changes on/in the fruit skin related to sunburn formation. Fruit quality measurements are used to point out differences in qualities (soluble solids, firmness, titratable acidity, and water content) between unaffected and sunburned areas of the fruit. The measurements of physiological and biochemical alterations (gas exchange, pigment analysis, enzyme activity, gene expression) give us a better insight to the mechanism of sunburn formation. Practical evaluations involve many procedures that are used by scientists to characterize the susceptibility of cultivars, evaluate protection technology, etc. For this purpose, the following methods are in use: expressing the percentage of the total fruit surface area affected by sunburn or the percentage of the total number of fruits damaged on the tree, or even a scale based on the severity of the symptoms occurred. All assessing methods and techniques described here have their pros and cons as well as their specific applicability, therefore any of these cannot be favored to use exclusively for assessing sunburn incidence. The combination of these techniques will be the best choice to meet a given research objective perfectly.
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Aminoglycoside antibiotics affect the in vitro morphogenic response of chrysanthemum and tobacco
93-104.Views:245Broadly the success of genetic transformation of plants requires non-chimeric selection of transformed tissues and its subsequent regeneration. With rare exceptions, most plant transformation protocols still heavily utilize antibiotics for the selection of transgenic cells containing an antibiotic-degrading selectable marker gene. The morphogenic capacity of in vitro chrysanthemum and tobacco stem and leaf explants change with the addition of aminoglycoside antibiotics (AAs). Of 6 antibiotics tested, phytotoxicity occurred at 10-25 and 50-100 pgml-I in chrysanthemum and tobacco explants, respectively, depending on the size of the explant and the timing of application. The presence of light or darkness also had a significant effect. The use of transverse thin cell layers (tTCLs) in conjunction with high initial AA selection levels supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow cytometric analyses demonstrate that regeneration can be predicted in both species, depending on the ploidy level of the callus. Endoreduplication was not observed in chrysanthemum, even at high AA levels, but occurred (8C or more) in tobacco callus, even at low AA concentrations (5-10 pgml-1). The higher the AA level, the greater the DNA degradation and the lower the 2C and 4C values.
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Studies on the effects of growing substrates and physical factors in sweet pepper forcing in context with the generation of calcium deficiency symptoms
61-65.Views:381In the publications available for us, exact levels of physical factors and those of the growing technology determining Ca2+ deficiency are rarely detailed. Although the influencing role of the various environmental factors (humidity, light, temperature) is known, we had only little information about their exact values which could be presented for the growing practice. Sweet pepper varieties of the same type grown in various substrates responded to the environmental factors in different ways. Our results revealed that increasing temperature of the root zone had the most significant effect on the incidence of Ca2+ -deficient fruits. Their amount, however, gave different results depending on the growing substrate. In forced sweet pepper grown in soil the proportion of Ca2+ - deficient fruits were significantly lower compared to the plants grown on rockwool. Fruits derived from forcing on perlite, in container were damaged the least by the blossom end rot deficiency symptoms. Our experimental results and technological suggestions are based on measurement results of three years.
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The effect of nitrogen supply on specific yield and fruit quality of apple (Malus domestica Borkh.)
7-21.Views:1522The aim of the present study was to determine the effect of nitrogen supply on yield and fruit quality of apple cultivars and to explore the relationships between canopy density and the different fruit quality parameters.
The experiments were carried out at Kálmánháza, in Eastern Hungary in a private orchard in 2003-2004. The response of four apple cultivars ('Elstar', 'Gala Prince', 'Granny Smith', 'Idared') to different nitrogen dosages was studied. The assessed and calculated indices were: yield, fruit diameter, fruit height, shape index, fruit mass, firmness, dry matter content and colouration. The results indicated that nitrogen fertilization has a significant effect on the yield and fruit quality of apple cultivars. The calculated specific yield values were reduced by the application of nitrogen via the increase in the volume of the canopy. An opposit trend was observed for fruit diameter, fruit height and fruit weight, which increased with increasing nitrogen supply. The reduced shape index caused flattening of fruits.
However, the improvement of fruit quality via increasing nitrogen dosage is only virtual, since these dosages increase the fruit size, but firmness, dry matter content and colouration are diminished, which decreases the value of the fruits on the market.
The authors also studied the relationships between canopy density responsible for assimilation and light supply of the fruits and the different fruit quality parameters. The closest linear inversely proportional relationship was found in the case of colouration. There was a negative linear relationship between canopy density and firmness or dry matter content. The relationship between canopy density and fruit mass could be described by a quadratic polinomial function.
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Comparative anatomical study of leaf tissues of scab resistant and susceptible apple cultivars
43-45.Views:385According to previous studies some anatomical features seem to be connected with resistance or susceptibility to scab caused by Venturia ineaqulis (Cke./Wint.) in case of a given cultivar. Study of leaf anatomy of three scab resistant (‘Prima’, ‘Florina’, MR–12) and two susceptible (‘Watson Jonathan’, ‘Golden Delicious Reinders’) apple cultivars have been made. Preserved preparations made of leaves has been studied by light microscope. Studied parameters were: thickness of leaf blade, thickness of palisade and spongy parenchyma, thickness of epidermal cells, thickness of the cuticle. By measuring leaf thickness and epidermal cell thickness visible differences appeared in certain cultivars, while most conspicuous difference has been shown in thickness of the cuticle.
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Shoot induction and plant regeneration from cotyledon segments of the muskmelon variety "hógolyó"
61-64.Views:353Cotyledonary segments of the casaba type muskmelon variety "Hógolyó" were used to induce organogenesis. Fifty different hormone combinations were applied to enhance the induction of shoot formation on the edge of the segments. The phases of organogenesis were followed with light- and scanning electron microscope. Shoot induction was achieved with high frequency. The shoots were transferred to hormone free media for root induction. The rooted plantlets were planted out to soil.
NAA was feasible and the method can be applied in transformation experiments.
