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  • Rootstocks for Cherries from the Department of Fruit Science Budapest
    63-66.
    Views:
    161

    Cherry rootstock breeding started at the Department of Fruit Science, SSU Budapest by the late 50-s and the activity can be divided into three main groups. In the first stage the activity was focused on collection of native mahaleb cherry (Prunus mahaleb L.) varieties lead by L. Sebők. After evaluation in the nursery and orchard tests there are four promising rootstock cultivars selected from this material: 'Korponay' used as self fertile seed tree, its seedlings are recommended for sour cherries. The mahaleb varieties 'Bogdány' (vigorous), 'Egervár' and 'Magyar' (medium vigour) are propagated by cuttings. The next project has started in 1979 with the aim to select self fertile mahaleb seed trees producing homogeneous seedling populations with reduced vigour. Inbred populations from isolated flowering self fertile trees were produced and planted out in 1980. The inbreeding of 'Korponay' self fertile P. mahaleb variety resulted in specimens with different fruit colour (yellow, red, black), fruit shape and size. From among them self fertile trees were selected with various growth characteristics. Seedlings of that self fertile mother trees (S2 population) were tested in seedbed, they showed homogeneous phenotype characteristics as liners in the nursery. As rootstock of 'Érdi bőtermő' sour cherry in the orchard most of the S2 lines proved to be less vigorous in comparison to SI popuplations. 'Érdi bőtermő' trees budded on certain S2 lines in the orchard are more productive than those on S1 ('Korponay' seedling). Characteristics of the S2 generation as seed tree were studied as well. We expect to get morphologically homogeneous seedling populations with different growth vigour and good productivity in the later inbred generations. In the last couple of decades the research activity concerning ground-cherry and its hybrids resulted in dwarfing rootstocks. Prunus fruticosa Pall. hybrids from the natural flora of Hungary were collected and artificial hybrids were created between P. fruticosa and mahaleb cherry. Most of them are in the initial tests, only one of them is before registration, named 'Prob', which is a dwarf rootstock for sweet cherry. By the screening of new hybrids medium vigorous or semi dwarfing and precocious rootstocks seem to be promising for the cherry industry.

  • Time of flowering and fertilisation of quince varieties
    9-15.
    Views:
    234

    Literature dealing with flowering and fertilisation of quince is scarce. Most controversial and scanty are informations on observations of self- and cross-pollination. According to our observations, differences in blooming time are few (2-3) days only, thus flowering of most varieties is synchronous. The varieties observed are grouped as early, intermediate and late flowering ones. Self fertility of the individual varieties, however, was not assessed unequivocally, therefore it is recommended, by safety reasons, to consider quince actually as a whole to be auto-incompatible. Artificial self-pollination (or rather geitonogamy) as well as cross pollination with other varieties increased substantially fruit set if compared with the results of natural self-pollination (autogamy). According to the fruit set of their open pollinated flowers, varieties have been classified according to fertility as low (below 10 %), medium (between 10 and 20 %) and high (more than 20 %). Cross fertility of varieties is highly variable depending on combination and on season. Contradictory data are probably due to the sensitivity of quince to conditions of search. Better fruit set was coincident with higher number of stout seeds per fruit. Well developed seeds are definitely a prerequisite of larger fruit size.

     

  • Fruit drop: II. Biological background of flower and fruit drop
    103-108.
    Views:
    298

    The most important components of fruit drop are: the rootstock, the combination of polliniser varieties, the conditions depending of nutrition, the extent and timing of the administration of fertilisers, the moments of water stress and the timing of agrotechnical interventions. Further adversities may appear as flushes of heat and drought, the rainy spring weather during the blooming period as well as the excessive hot, cool or windy weather impairing pollination, moreover, the appearance of diseases and pests all influence the fate of flowers of growing and become ripe fruits. As generally maintained, dry springs are causing severe fruit drop.

    In analysing the endogenous and environmental causes of drop of the generative organs (flowers and fruits), the model of leaf abscission has been used, as a study of the excised, well defined abscission zone (AZ) seemed to be an adequate approach to the question. Comparing the effects active in the abscission of fruit with those of the excised leaf stem differences are observed as well as analogies between the anatomy and the accumulation of ethylene in the respective abscission tissues.

  • Some physical properties of sweet cherries
    63-70.
    Views:
    172

    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.

  • Fruit drop: I. Specific characteristics and varietal properties of fruit drop
    59-67.
    Views:
    370

    The basic conditions of fruit set (synchronic bloom, transfer of pollen, etc.) still do decide definitely the fate of the flower in spite of the best weather conditions. Beyond a set quantity of fruits, the tree is unable to bring up larger load. A system of autoregulation works in the background and causes the drop of a fraction of fruits in spite of the accomplished fertilisation and the equality of physiological precedents. This study discuss this physiological process based on the international specific literature. The further development of fruits maintained on the tree depends mainly on the growing conditions (e.g. water, supply of nutrients, weather adversities, pruning, fruit thinning, biotic damages, etc.), which may cause on their own turn fruit drop especially at the time of approaching maturity.

  • Rootstock evaluation in intensive sweet cherry (Prunus avium L.) orchard
    7-12.
    Views:
    202

    During 2000 and 2007, rootstocks of different vigor have been tested in a high density sweet cherry orchard with 'Vera '® and 'Axel'® cultivars at 4 x 2 meter row and plant distance. Trees are trained to Hungarian Spindle with permanent basal branches; in the alley way naturally grown grass is managed by mowing. The first considerable fruiting was in 2004. Every year we measured trunk and canopy parameters of the trees, productivity and fruit size. Our conclusion is that the rootstocks considerably affected the growth, precocity, as well as tree and orchard productivity, fruit weight of sweet cherry cultivars, but these rootstock effects are modified by cultivars, except for growth vigor. According to our results Cema, SL 64, and Bogdany are vigorous rootstocks, moderate vigorous are MaxMa 97, Pi-Ku I , and Tabel® Edabriz, Gisela® 5 and Prob are dwarfing rootstocks. Besides the precocious Gisela® 5 also mahaleb rootstocks CEMA, Bogdany and SL 64 showed considerable precocity, which can be explained by the larger bearing surface to the time of turning to bearing, and a similar or relative large density of burse shoots on fruiting branches. Cumulative yield of 'Axel'® was the highest on Bogdany and on Cerna, contrary to Gisela® 5, which produced only 50% of the previous ones. Cumulative yield of 'Vera'® was the highest on SL 64, and no significant difference was found, compared to trees on rootstocks Cema, Bogdany and Pi-Ku I . Cumulative yield production of trees was smaller on Gisela® 5, Prob, Max Ma 97 and Tabel® Edabriz rootstocks. Corresponding to the literature data of yield efficiency calculated on TCSA basis was highest on Gisela® 5 rootstock. but the efficiency calculated on canopy volume of 'Axel•® trees was similarly high on CEMA and Bogdany, and that of 'Vera'® trees relatively high on CEMA, Bogdany, SL 64 and PiKu I rootstocks. When calculating orchard efficiency al spacing 4 x 2 meters (1250 tree/ha), we received highest yield values on Bogdany, CEMA, SL 64, and PiKu I rootstocks, with large fruit weight. Rootstocks also affect fruit weight. We measured the largest fruit weight on trees on Bogdany.

  • Comparison of varying pollen source on productivity of sour cherry (Prunus cerasus L.) cultivars
    23-26.
    Views:
    197

    Fruit set of five sour cherry cultivars (‘Újfehértói fürtös’, ‘Éva’, ‘Petri’, ‘Pándy 279‘ and ‘Csengôdi’) of eight years-old trees grown in Újfehértó, located in the Eastern north part of Hungary have been studied over two years (2008 & 2009). Following reciprocally cross-pollination, free-pollination, self-pollination (autogamy) artificial self-pollination (geitonogamy) were studied. The results show that both maternal and paternal parent cultivates had significant effects on the percentage fruit set. Significant differences have been found in fruit set among years and among pollination treatments. Fruit set of free-pollinated Pándy 276 cultivar was low and seasonally highly variable. The yield of this cultivar on self-pollinated flowers was nearly 0%, and in this treatment the maximum yields did not reach 10% in any of the examined cultivars. There was no significant relationship in the fruit set of free-pollination and natural self-pollination treatments.

  • Reactions of different plant organs of pear cultivars to Erwinia amylovora infection
    17-21.
    Views:
    123

    Research project has been initiated in 1999 with the aim of evaluating the degree of susceptibility/resistance of pear cultivars grown in Hungary to fire blight disease caused by Erwinia amylovora. The recently selected promising cultivars were also examined. Inoculation experiments were conducted in controlled greenhouse conditions because of quarantine regulations in Hungary. Following the disease process, development of symptoms of plant organs (shoots, flower parts, fruits) was observed. Suspension of two E. amylovora strains (Ea 21, Ea 23) isolated from pear was used in a mixture (5x108 cells x m1-1) for the inoculation. Twenty-six pear cultivars were examined and grouped into four categories: low susceptibility, moderately susceptible, susceptible and very susceptible. Most of the cultivars were susceptible or very susceptible while some promising 'Eldorado', 'Harrow Delight' and `Hosui' showed low susceptibility.

  • Evaluation of a simple fruit tree structural model
    123-126.
    Views:
    155

    A simple three element tree structure model of Lang, 2006 was tested in plum orchard using two different inertia fruit tree shakers. The first was a slider crank type one; the second had rotating eccentric weights. The parameters of both were chosen to give similar frequency and amplitude output in average orchard conditions. Orchard experiments were carried out shaking the trees with both machines at several frequencies and shaking heights. The measured acceleration and amplitude values were plotted on diagrams together with the calculated acceleration and amplitude curves of the fruit tree-shaker machine model. Choosing the right fruit tree parameters, such as apparent spring constant, damping coefficient, reduced trunk mass and coefficient of elasticity of the trunk the measured and calculated values coincided well. This proves the ability of the fruit tree model for optimising the shaker parameters to any given orchard.

  • Structural differences arise between fruit cuticles of two apple cultivars during long term cold storage
    26-29
    Views:
    258

    Apple fruits are covered by hydrophobic cuticle that provides protection against desiccation, pathogens, excessive water absorption and radiation. The features of cuticle affect the quality and storability of the fruits. It was aimed to evaluate the correlation between peel ultrastructure and weight loss in fruits covered by waxy bloom (cv. Florina) and without bloom (cv. Red Rome van Well) during 4-month cold storage. SEM (scanning electron microscopy) was used for visualization of the fruit surface and fruit weight was also measured. Several studies have revealed that there may be correlation between the ultrastructure of cuticle and its water permeability. Our results confirmed this phenomenon in case of two cultivars. The weight loss per fruit surface area unit of ‘Florina’ was found significantly higher than that of ‘Red Rome van Well’. At the same time the cuticular surface of the fruits contained more micro-cracks in case of the former cultivar. These data confirmed the relationship between the density of cuticular micro-cracks and the water vapour permeability. We concluded that this feature is more significant than the amount of natural waxy bloom on fruit surface.

  • Some important growing characteristics of apple and apricot cultivars in two fruit growing regions in Romania
    51-56.
    Views:
    138

    The aim of this study was to determine some important growing characteristics of 5 resistant apple (Rajka, Rubinola, Topaz, Otawa and Goldstar) and 7 apricot (NJA 19, Goldrich, Harcot, Venus, Comando, Olimp, Cea mai buna de Ungaria) cultivars in two fruit growing regions in Romania from 2000 to 2003. Height of the apple trees (4-year-old tree) ranged between 1.96 m (cv. Topaz) and 2.39 m (cv. Rubinola). Diameter of the crown ranged from 0.96 m (cv. Goldstar) to 1.12 cm (cv. Rajka). The trunk diameter ranged from 3.5 cm (cv. Goldstar) to 5.0 cm (cv. Rajka). The surface of the trunk section was the lowest for cv. Goldstar (9.7 cm') and the largest for cv. Rajka (19.6 cm). Height of the apricot trees (4 years old tree) ranged between 2.69 m (cv. Venus) and 3.38 m (cv. NJA - 19). Diameter of the crown ranged from 2.59 m (cv. Comandor) to 2.77 m (cv. Cea mai buna de Ungaria). The trunk diameter ranged from 9.54 cm (cv. Goldrich) to 13.30 cm (cv. NJA - 19). Length of annual branches was the lowest for cv. Goldrich (45.1 cm) and the highest for cv. NJA - 19 (83.8 cm). Bud swelling of apricot trees began on 8 March for cv. NJA - 19 and ended on 11 March for the control cultivar (Cea mai buna de Ungaria). The blooming started on 16 March for cv. NJA - 19 and 27 Mach for the control cultivar. Duration of fruit growth was 89 days for cv. NJA - 19 and 128 days for cv. Comandor. When the temperature decreased to 1.5 °C (in 2001), percentage of viable pollen grains ranged between 48.86 % (cv. Olimp) and 91.57 % (cv. Venus). The germinating grains ranged from 31 % (cv. Olimp) to 90 % (cv. Harcot). Free pollination was the lowest for cv. NJA - 19 (29 %) and the highest for cv. Harcot (41%), while self-pollination ranged between 6 (cv. Olimp) and 11 % (cvs. Comondor and Harcot). Apple yield ranged from 16.65 t/ha (cv. Otawa) to 24.35 t/ha (cv. Rajka) and the differences varied from 4.45 t/ha to - 3.25 t/ha compared to the control varieties. Apricot yield ranged from 11.47 kg/ tree or 9.53 t/ha (cv. Cea mai buna de Ungaria), to 38.83 kg/tree or 27.34 t/ha (cv. Olimp) and the differences varied from 3 t/ha to 17 t/ha compared to the control varieties. Apple fruit weight ranged from 162 g (cv. Otawa) to 222 g (cv. Goldstar) and apricot fruit weight from 42.52 g (cv. Goldrich) to 68.38 g (cv. Comandor). Color, taste and aroma were very specific to cultivars.

  • Strategy of the sour cherry verticum in the Northern Great Plain Region Hungary (Analytic study)
    7-31.
    Views:
    216

    Sour cherry growing and consumption grows dynamically around the world. The present volume of 1 million tons will incerase within 10 years with 20-30, or even with 50%. In the world wide sour cherry production, Europe is a decisive factor, i.e. 2/3 of the volume is grown there. Prominent capacities are concentrated in East-Central Europe, mainly Poland, Germany and Hungary. In the future, new concurrent exporters are expected on the European market as Turkey, Iran, Serbia-Montenegro. Hungarian sour cherry production has rich traditions, so the growing techniques and the assortment of sour cherry varieties make Hungary a „Great Power" on this field. Fresh fruit and products developed from sour cherry represent values distinguished as „Hungaricum" on the markets. Sour cherry growing and the path of its products are one of the „pulling branches" of Hungarian fruit growing. Sour cherry occupies 15% of area for fruit growing and 40% within the stone fruits. Sour cherry was grown widely in Hungary, it was grown everywhere as for utilizing waste areas. This is the main reason that yields are low as a mean of 15 000 ha and the volume is low (50-60 000 tons) only. To that poor figure the heavy infections of Monilia contributed substantially in the last couple of years. The two most valid arguments of using the present varieties as the best solution are 1) the cross bred new varieties, and 2) the selections of local, traditional varieties, which substituted the earlier dominant 'Pándy meggy' variety, which had a good quality but yielded poorly. Sour cherry growing of Hungary shifted from the dry regions of the country toward the cooler and more humid regions, where the weather excesses secure a less risky production. The most decisive region is the Norther Great Plain Region comprising Szabolcs­Szatmar-Bereg county, where more than the half of the Hungarian sour cherry volume is produced, and which is bound to increase its production in the future. The majority of sour cherry produced in Hungary is processed, moreover, an important fraction of the exported fresh fruit is also used by the industry. The main importer of Hungarian sour cherry is Germany. The industry manufactures mainly canned products, a smaller fraction will be processed to other products. The expected volumes of sour cherry grown in Hungary in the next 5 and 10-year-period was estimated from data based on the ratio of young plantations, predicted consequences of the global climatic changes, phytosanitary aspects, furthermore, on the development of the technological level. In the region, the volume grown within 5 years, 40 000 t/year will increase within 10 years to 55 000 t/y. The processing in Hungary is not sufficiently differenciated, which is attributed partly to the characters of the varieties, partly to the weaknesses of the processing industry. One of the reasons is the suitability of varieties mainly for canning products. Processed sour cherry products could not be sold at the same price levels achieved by concurrent sour cherry growing countries. The vertical structure of the path of products of sour cherry disposes of adequate processing capacity being ready to be developed or there is sufficient intention of making investments for the purpose of manufacturing special sour cherry products. Significant tasks of development are actual in the field of the ecological and biological conditions of production. Volume and yield security as well as the maturity time and diversification of processing possibilities are the main endeavours in widening the assortment of varieties to be grown in the near future. The main objective in growing techniques is the modernization of phytotechnical procedures, and new solutions of methods of mechanical harvesting and related technical innovations are necessary in the sour cherry verticum. A key question is the effectiveness of phytosanitary procedures with special reference to the Monilia fungus and to the cherry fruit fly as the most important pest. There are two points of break through in the Hungarian sour cherry verticum. On the one hand, meeting the increasing demands in fuits for fresh consumption, on the other hand, the diversification of processed sour cherry products and their introduction to the markets. Both are aiming to increase the competitiveness of the Hungarian sour cherry. For that purpose, outstanding varieties and excellent as well as internationally recognised fruit qualities are ready to be utilized. The most susceptible problems of the Hungarian sour cherry verticum are associated with marketing, alliance of the grower-and processor organisations and their co-operation because no overall integration within the sour cherry verticum has been established yet. Most urgent necessity as well as possibility of changes are felt in the Northern Great Plain Region.

  • Production technology and fruit tree nutrition
    39-42.
    Views:
    123

    Fruit yield quality and quantity are effectively enhanced if healthy vegetative conditions are ensured. These optimal conditions — i.e. the balance between shoot development and yield — can be achieved by the rationalization of the production technologies, such as:

    • reduction of the size of the crown
    • adaptation of the severity and method of pruning to the conditions of the actual year
    • removal of the shoot tips
    • timely fruit thinning

    By establishing an improved level of plant nutrient uptake, this will ensure a healthy balance between shoot growth and yield.

  • Evaluation of sour cherry (Prunus cerasus L.) and European plum (Prunus domestica L.) varieties for making dried fruits
    119-124.
    Views:
    204

    The aim of our drying trials was to determine the drying suitability of stone fruits. The tested species were sour and sweet cherries and European plums too. Data and results of sweet cherry drying were published earlier (Klincsek et. al. 2005, 2006).This article containing results of twenty sour cherry and six European plum varieties. Laboratory tests, drying processes and sensory testing were done at Fruit Quality Testing Laboratory of Fruit Science Department of Corvinus University of Budapest. The sensory tests and their valuations were done by the instruction of National Institute for Agricultural Quality Control. In the case of sour cherries by one year data in 2004 we divided fruits to five categories by suitability for making dried fruit. Varieties in the first two groups are the followings: most suggested for making dried, fruits: 'Meteor korai' and `Érdi jubileum'; suggested: 'IV-3-48' and `Piramis'.In the case of European plums three varieties can be suggested for making dried fruits from the six tested cultivars: ‘Révfülöpi’, Althann gage' and `Besztercei'.

  • Importance of boron in fruit nutrition
    39-44.
    Views:
    275

    Boron (B) is an essential micronutrient in plants especially in fruits. Despite of this fact there are very few information about its application, uptake and symptoms in Hungarian fruit growing sector. Nowadays we should consider the effects of weather conditions on soil B availability increasingly according to the climatic anomalies. Identifying of internal and external symptoms of plant parts (leaf, fruit) is help for growers to recognize the deficiency and excess symptoms in time. Methods and application rates of boron fertilization provide further information for growers to achieve qualify-oriented fruit growing among Hungarian conditions. The aim of this minireview is to focus on the importance of boron in fruit nutrition.

  • Assessment of fruit firmness of pepper using non-destructive physical measurements, in response to different growing and pruning technologies
    59-62.
    Views:
    117

    The European market demands vegetable products of the highest quality and this commercial quality must be maintained till the goods reach the customer. One of these important quality parameters is the fruit firmness of pepper.

    The experiments were aimed at to find out the influence of different growing methods (soil or rockwool-based) and pruning technologies (to 1, 2, 3 or 4 shoots) on the yield and fruit firmness of three pepper varieties (HO F1, Karpia Fl and Pritavit F1) which are common in Hungary. Fruit firmness was measured by the non-destructive impact method.

    On the basis of the results, in unheated forcing the pruning to 1, 2 or 3 shoots can be suggested for all three varieties, as well as the utilisation of rockwool in their growing.

    The non-destructive impact method has been found suitable for testing the fruit firmness of pepper varieties. In the experiments involving different growing mediums pepper stands were found to show significant differences, however the different pruning methods had no significant influence on fruit firmness.

  • Organic versus integrated apple growing: II. differences in fruit quality parameters
    61-63.
    Views:
    228

    The aim our study was to establish whether significant differences in nutrients uptake and quality of fruit exist
    between organic and integrated grown apples. The study was performed at the orchard Fruit Research Station, University of Debrecen, at Debrecen-Pallag during 2002–2004. Diameter (mm), weight (g), firmness (N/cm2), dry matter (%) and Vitamin C in fruit were determined. Diameter data showed that the size of apples strongly depended on cultivars and organic apples were larger than integrated ones. Moreover, the effect of year and species strongly affected the apple diameter, size and weight. Measured data of firmness were good agreement in data of diameter and weight. Larger fruits have lower values of firmness due to the structure of fruit flesh. Dry matter content of apples varied between 14.66 and 18.07 in integrated, and 12.87 and 17.29 in organic apples according to cultivars. Values were affected by years and cultivars. From results it was evident that the dry matter content of apples affected by production system. It was lower in organic samples than integrated ones.Vitamin C content of apples was stronger affected by species and years than production system.

  • Field evaluations of 14 sweet cherry cultivars as pollinators for cv. Regina (Prunus avium, L.)
    75-77.
    Views:
    216

    In this study, the pollen of 14 sweet cherry cultivars (‘Anella’, ‘Duroni 3', 'Badacsony', 'Cristalina', 'Ferbolus', 'Ferrovia',

    'Georgia', 'Hudson', 'Kordia', 'Sam', 'Schneiders’, ‘Spate’, ‘Knorpelkirsche', 'Skeena', 'Summit', 'Sylvia') was used to fertilize the emasculated flowers of sweet cherry cv. 'Regina'. Fruit set was assessed three times during fruit development: 14 May, 30 May and 27 May 2007. We observed full incompatibility among the 14 cultivars for cv. 'Cristalina', which is in the same S-allele group as cv. 'Regina'. After analysis of our data, we have results about fertilization efficiency of the cultivars. Most of the evaluated cultivars are inadequate to fertilize cv. 'Regina' to a sufficient degree. There were two exceptions, cv. 'Sam' and cv. 'Skeena', where percentage of ripened fruits was above 20%. These two cultivars can guarantee such a pollination, which ensures ample quantity of ripened fruits. Results of this study have proved three other cultivars to be quite good pollinators for cv. 'Regina'. In conclusion, ideal pollinators for cv. 'Regina' could be — apart from above-mentioned two cultivars, 'Sam' and 'Skeena' — cvs. 'Sylvia' and 'Bianca', which was suggested by more literature sources.

  • Susceptibility of some traditional pear cultivars of Hungarian and foreign origin to the pathogenic bacterium Erwinia amylovora
    41-45.
    Views:
    138

    Fire blight, a disease caused by the bacterium Erwinia amylovora (Burrill) Winslow et al., has been causing serious damage in Hungarian pear plantations since 1996. A prospective control measure could be the use of resistant cultivars. For that purpose ten pear cultivars have been tested under laboratory and greenhouse conditions for resistance to Erwinia amylovora strains collected in Hungary. Six of these cultivars are Hungarian ones of unknown origin, while four are traditional old varieties. Resistant cultivars should serve as germplasm for future breeding. Inoculations were made with a mixture of different pear isolates of the bacteria collected from various growing regions of Hungary (Ea 21, 23), at a density of 5x108 cells/ml. Susceptibility/resistance has been assessed on the basis of intensity of blight symptoms observed on shoots, flower parts and fruits. Cultivars were assigned to three susceptibility groups (low, moderate and high). Complete resistance was not found among the cultivars tested. The highest level of resistance was found in cultivar 'Kieffer', while the other cultivars displayed either moderate or high susceptibility to infection.

  • Interaction of nutrient supply and crop load of apple trees (Malus domestica Borkh.)
    33-35.
    Views:
    148

    Long term fertilisation trials were combined with storage experiments with 'Jonathan' apple trees and fruits to study influence of tree nutrition on quantity and quality of crop. The site of experiments is a typical Carpathian-basin environment with loamy silt soil, high lime content and arid summers. Conclusions has been drown from six years' set of data. Augmented levels of soil fertilisation increased cropping capacity of apple trees, however, the fruit load has not met with cropping capacity in every year. More the def cit came into view in crop load, less the fruit quality resulted in. The deficit in cropping capacity, however, could not have been determined with simple rates as fruit weight per trunk circumference or similar. Better determination was obtained where foliar nutrient contents were correlated to crop per tree figures. In general terms, the N and Ca content in leaves increased with yields when K and P content formulated reciprocally. When storage quality of 'Jonathan' apple fruits were related to crop load (kg/tree), influence of crop deficit became visible. As the crop load and foliar nutrient levels interacted, the fruit quality (number of disordered apples after 6 month of storage) subjected of both physiological phenomena. Higher determination degree were obtained when crop load was assessed together with single or multiple foliar analysis data.

  • Resistance Gene Analogs (RGA) as a tool in fruit tree's breeding
    7-15.
    Views:
    175

    Breeding for pest and disease resistance comes as a major objective behind the fruit traits. To increase the effectiveness of fruit resistance breeding application of the Marker Assisted Selection ( MAS) is advantageous. For generating molecular markers which enable the following of interesting traits basically two methods are available: targeted marker design based on conservative region of already known Resistance ( R) gene sequences or randomly generated markers. The creation  and the application  of  these homology  based  markers  are the object of this review in  the main  temperate zone  fruit species.

  • Pollen morphology of fruit species
    49-57.
    Views:
    1037

    Size and surface morphology of pollen has been studied in 87 twit varieties of 10 fruit species during the period of 1990-1995. No preceding work of that type came to our knowledge, yet.

    The samples comprised a wide variety of cultivars included male sterile, self-incompatible, partially self-fertile stone fruits, diploid and hexaploid plums, diploid and triploid apples.

    The large number of species and varieties facilitated the comparison of items within and between the respective species.

    It was stated that the size, shape and surface morphology of pollen is genetically determined and those data, combined with other variety characters, are suitable for the classification and distinction of varieties.

    In assessment of pollen size and shape, their moisture content is crucial. The major diameter of the swollen pollen as well as the length and width of the dry grains are characteristic to species and/or to variety.

    The width and shape changes largely with moisture content. Large grains are proper to quince, apricot, peach and almond, medium sizes are found in apple, sweet cherry, sour cherry, European plum, whereas small size is typical to Japanese plums.

    The low number of varieties studied does not allow conclusions concerning differences within pears, quinces and almonds as species. In the rest of species, valid differences have been registered as between varieties.

    Within species, as apple and plum, the effect of ploidy (i.e. number of chromosomes) was expressed in the size of their pollen. In stone fruit species, the correlation between size. of anthers and size of pollen grains was positive.

    Genetic relations between the self-fertile sour cherry varieties of the Pándy type (Debreceni bőtermő, Kántorjánosi, Újfehértói fürtös) as well as the self-incompatible apricots of "giant" fruit size are supposed to be analysed by pollen studies but there did not turn out any decisive conclusion, yet. Other characters also should be considered.

    The assembly of pollen characters is decisive in the determination of the variety. The ratio of empty pollen grains, the grain size and the density as well as the size of the pits on the surface are best suited to distinguish pollen lots.

     

  • Association of European plum varieties in the orchards
    21-24.
    Views:
    243

    The flowering phenology, blooming time and inter-fertility relations of 63 European plum varieties has been studied at growing sites with different ecological conditions during a 10 year long period. The purpose was to develop a system of variety combinations which approaches an optimum in fertility as long as inter-fertility relations will cease to be a limiting factor of yield. According to their blooming time, varieties are assigned to 5 groups: very early, early, medium, late and very late. As for their fertility relations, four groups are formed: self-sterile (0%), partially self-fertile (0.1 to 10 %), self-fertile (10.1 to 20 %) and highly self-fertile (more than 20 % fruit set with self pollination). The four categories of fruit set at free pollination are also relevant to the grower: low (less than 10 %), medium (10 to 20 %), high (20 to 40 %) and very high (more than 40 % fruit set).

    By artificial cross pollination, one combination Cacanska najbolja x Stanley proved to be mutually inter-incompatible. Blocks planted to a single self-sterile variety flanking a pollinizer variety proved the spacial distribution of the pollen. The reduction in fruit set was already apparent in the second row away from the pollinizer trees. In a large plantation, without bee hives, relatively low yield was stated on self-sterile trees even close to the pollinizer.

    In the case of self-sterile and partially self-fertile varieties, a combination of three varieties is recommended. The blooming period of the pollinizer variety should overlap the period of the self-sterile variety at least by 70 %, and the distance should not exceed 15 to 20 meters. Association of self-fertile varieties may also enhance the productivity of the trees. In that case an overlap of 50 % in blooming time and a maximum distance between the varieties of 30 to 40 meters will be sufficient.

     

  • Possibilities and limits of use plastic constructions in fruit growing technologies
    71-75.
    Views:
    214

    On the Experimental Station Pallag of Debrecen University different combinations of fruit species and rootstocks have been raised under and without plastic foil cover in 2002. The growth and productivity of the grafts was our objective of comparison. Results revealed substantial differences in fruit set and yield depending on species and varieties. Sweet and sour cherry varieties grew much shorter under the plastic cover, whereas apricots, peaches and plums set fruit much more eagerly compared with the trees outside the plastic cover. Outside the plastic cover, the trees were much more developed at the beginning of their fruiting period. In spite of that, the growing processes were more intense under the foil. The differences are allegedly due to the repeated summer pruning necessary under the restricted space of the foil, on the other hand, due to the root concurrence because of the dense planting. Regarding the inner properties of the fruits, soluble solids, sugar and acids were higher outside, whereas macro- and mezzo-elements (P, K, Ca, Mg) were more abundant in fruits grown under the foil cover. Further efforts to explore those relations with other varieties and rootstocks are justified.

  • Effects of meteorological factors on fruit qualities of 'Fuji' apple in Korea
    20-23.
    Views:
    102

    'Fuji' apples from five different growing regions in Korea were analyzed for internal and external quality attributes which included fruit shape, color and sugar. Significant relationships were observed between final fruit color (a*) and air temperature in August. Red color was poorly developed where the average temperature in August was over 25 oC. The sugar composition was significantly different depending on region. The sucrose content decreased with increasing temperature above 16 oC during the harvest season. The fruit shape was not affected by agro-climatic conditions in this study.