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  • The effect of nitrogen supply on specific yield and fruit quality of apple (Malus domestica Borkh.)
    7-21.
    Views:
    196

    The 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.

  • Summer pruning of sweet cherry trees and an inquiry of winter frost damages
    41-44.
    Views:
    285

    One of the most demanded research projects is the intensification of fruit production. The use of dwarfing stocks is a moderate solution as their effect is scarcely satisfactory. Climatic conditions of Hungary are continental in Eastern Europe, where Atlantic and Mediterranean effects are interacting with the continentals in a kind of basin with characters of its own. Capricious meteorological episodes are often disturbing the security of development and fruiting of trees:
    • winter frosts are damaging the cambium and fruiting structures of trees
    • late spring frosts destroy cambium and flowers
    • early autumn frosts hurt the leaves
    • excessive precipitation impairs the growing fruits
    • drought periods during the summer caused water stress disturbing water husbandry.

    Vigorous stocks still prevail in the practice, and they ought to withstand challenges of weather hazards. The strong vigour of plants delaysthe process of senescence and the tendency of getting bald, and regeneration of plants is a sign of vitality. In present research, the trees have been trained on vigorous Prunus mahaleb stocks. Summer pruning was one of the important tools of intensive growing techniques. They were compared with traditional techniques and with plastic foil protected trees observing the vegetative as well as generative growth of them.

  • Connection of fertilization conditions of sour cherry and meteorological parameters
    17-21.
    Views:
    243

    Our analyses showed that the degree of free fertilization is mostly influenced by maximum temperature and sunshine duration.We found that free fertilization ratio increases with higher daily maximum temperatures; similar results characterise sunshine duration as well, namely we observed higher free fertilization ratio at higher sunshine duration values. Total amount of precipitation during the period between blossoming and maturity and the difference between the average daytime and night temperatures have an important role in the tendency of maturity time. Photosynthesis and respiration are essentially significant in the development of biological systems. These two processes are mostly regulated by the daytime and night temperatures. Therefore, it is not surprising that if the difference between daytime and night temperatures is large, it means intensive photosynthesis and a low degree of respiratory loss. Under these conditions intensive development and ripening can take place; however, in case of a low temperature difference intensive respiration slows down the process of development. Duration of ripening is also significantly influenced by the amount of precipitation of the period between blossoming and maturity.Abundant precipitation slows down the process of ripening, while dry weather accelerates it. Self-fertilization takes place in a space isolated from the environment. In spite of that, we found that effectiveness of self-pollination significantly depends on the meteorological conditions. Degree of self-fertilization is influenced directly by temperature and indirectly by other climatic parameters. We found a significant connection between the values of maximum and minimum temperatures during blossoming and the ratio of self-fertilization. Increase of maximum temperature reduces the effectiveness of self-pollination.A 1 °C increase of maximum temperature reduces self-fertilization ratio by 0,6%. In the case of minimum temperature we can state that the morning minimum temperature of 7,5–8,5°C is the most favourable. If minimum temperatures are under 4 °C or above 12 °C, self-fertilization ratio reduces to the quarter of the value characteristic at 8 °C. We believe that the effectiveness of self-fertilization can be improved considerably by the rational placement of isolator bags within the crown area, avoiding their placement to the external, western crown surface.

  • Utilisation of data raised in blooming phenology of fruit trees for the choice of pollinisers of plum and apricot varieties
    35-41.
    Views:
    321

    Information concerning the blooming time of stone fruit varieties is, first of all, an important condition of finding suitable pollinisers securing adequate fruit set. For that purpose, varieties are assigned to blooming-time-groups. Depending on the number (3 or 5) of the groups, i.e. the length of intervals separating the groups established, pollenisers are to be chosen for self-incompatible and partially self-fertile varieties belonging to the same blooming-time-group. The mutually most overlapping blooming periods of the respective varieties should be found by raising data of their blooming phenology, i.e. dynamics, which is compared by drawing their phenograms and calculating blooming (V) indices. Variety combinations have to be checked, however, concerning mutual fertility relations of the respective pairs of varieties. That is most important in the case of Japanese plums because of the abundant incompatible combinations. Synchronous blooming has been determined by assigning the varieties to blooming-time-groups, or comparing overlaps of blooming phenograms, or by blooming (V) indices. Synchronous blooming phenology has been studied in European plum varieties (111 varietiy combinations) Japanese plums (156 variety combinations) and apricots (153 variety combinations) under Hungarian conditions, over several seasons. In determining overlaps, the less favourable season has been considered as decisive. Polliniser combinations have been chosen with at least 70% synchronous blooming. Blooming time of varieties is an important part of the variety descriptions. Blooming dates may serve also for the estimations of frost risk or security of yield.

  • Temporal changes of the frequency of spring frost damages in the main fruit growing regions in Western Hungary and in East Hungary
    81-87.
    Views:
    374

    Most of the risk in Hungarian fruit growing is the damage caused by late spring frosts. The frequency of late frosts seems to increase nowadays. The aim of the study was to check this contention: what is the real probability of the damages. Based on earlier experiences, the physiological LT50 function has been elaborated for new fruit varieties, which are eligible to moderate the danger when being threatened by frost. By means of this technique, the probability of freezing is distinguished between frost susceptible, frost resistant and medium frost resistant fruit species and varieties around their blooming time. The degree of frost damage depends on the duration and severity of the low temperature and not at least on the frost tolerance of the plant. For that purpose, the frequencies of frost damages were studied at two Transdanubian and two Trans-Tisza fruit growing sites by means of a meteorological database for the 60-year-long period 1951–2010. Being aware of the LT50 values changing during the phonological phases of the fruit trees from budding, bloom, fruit set and fruit growth, the number and date of critical (frosty) days could be settled. An important role is attributed to the orographic relief and the height above the sea level of the site, as 20–30 m differences and expositions may become decisive within the same plantation. The spatial distribution of damages is also dependent on the air circulations within the Carpathian basin. At the southern and northern borders of the country, especially valley bottoms represent additional risks of frost. Most spring frost damages are experienced in April 20–22, and cause heavy damages by temperature minima between – 3°C and – 6°C. The severity of damage depends largely on the temperature of the preceding few days. The earlier bloom the heavier damage is expected. The study is emphasising the importance of the varieties. Frost tolerance of some varieties may lower the risk of spring frosts by 40–50%, as experienced on the plantations. The quantifi cation of the risks based on data raised during the last years will be suitable to defi ne the security of yields of each growing site successfully.

  • Climatic indicators regarding the rest period of sour cherry
    49-52.
    Views:
    215

    Sour cherry production in the world is increasing gradually. Profitable production, i.e. yield, depends largely on weather conditions. If Hungary wishes to keep up with the most successful countries, attention should be paid to the weather during the dormancy period, being definitely decisive from the points of view of quality as well as quantity. In order to predict the expected risk factors, characterisation of the most important weather parameters is necessary. For that purpose, the database of the Institute of Research and Extension Service for Fruit Growing at Újfehértó Ltd. has been utilised. Records of weather conditions were collected throughout the period 1984-2005, i.e. daily minimum, maximum and mean temperatures (°C), and phenological diary of sour cherry varieties ’Újfehértói fürtös’, ’Kántorjánosi’ and ’Debreceni bôtermô’. For the future expectations study we have used the RegCM3.1 regional climate model with 10 km resolution. Data of 4 indicators have been traced: Average temperatures, Number of days without frost, Maximum length of periods without frost, Maximum length of frosty period. On the one hand, we surveyed the changes; on the other hand, estimates have been attempted for the future changes expected during the following decades.

  • Results of experimental storage of sour cherry (Prunus cerasus L.) fruit
    65-78.
    Views:
    269

    In utilisation of sour cherry cultivars, the paradigm has gradually changed in the sense that fresh consumption gained much more attention than before on a worldwide scale. Consequently, much more attention is paid to the problems connected with the storage, i.e. preservation of fresh fruit for direct consumption. It is a genuine interest of growers, traders as well as of consumers to be informed about the possibilities of preserving economically the fresh status for a longer period after harvest during the warm summer weather in addition to the lengthening of the harvest season by choosing cultivars of different dates of ripening. Recent results of purposeful experiments indicate that the storability of the fruit of 6 main Hungarian sour cherry cultivars is on the same level ('Érdi bőtermő, 'Debreceni bőtermő’, 'Újfehértói fürtos', 'Kántorjánosi', 'Éva', 'Petri'). The traditional conditions facilitated the maintenance of freshness over a 5-week-long period, and the loss of volume was less than 7%. During the first 2 weeks, there was no difference between the cultivars regarding loss of volume and decay, moreover, the effect of time elapsed after harvest and of adversities of transport was not significant. It could be stated that 2 week of storing is safely feasible. We need only 2 °C temperature and 90% of relative humidity. The relations of oxygen and CO2 of the atmosphere is less decisive than temperature alone. No essential difference has been registered between the storing in plastic trays versus plastic boxes either. A study was performed to assess the modified atmosphere packaging (MAP) effect on Hungarian sour cherries growing in Iran (`Érdi bőtermő and ‘Érdi jubileum') shelf life. The harvested fruits stored at 0 °C under modified atmospheres (15% 0, and 10% CO2 and 75% nitrogen) for 6 weeks. Descriptive analysis showed that sour cherry stored in control condition had a higher deterioration rate than those stored in under modified atmosphere, which showed a lower rejection rate and a longer shelf life than those stored in modified atmosphere.

  • The effect of the limitation of insect pollination period on the fruit set and yield of temperate-zone fruit tree species
    90-95.
    Views:
    186

    The duration of effective bee pollination period was limited by caging flowering branches for shorter or longer time in blooming fruit trees in a number of experiments during the past decades. In the case of self-sterile fruit species and cultivars (apples, pears, quinces, some plums, some sour cherries) even partial limitation of the effective duration of bee pollination period significantly reduced the fruit set and the yield. In the case of self-fertile apricots the effect of the total and also the influence of partial limitation of bee pollination period was the same as in the case of the mentioned self-sterile fruits. On the other hand, in the case of another self-fertile fruits (some plums, some sour cherries), the effect of partial limitation of bee pollination period was usually small, but complete (or incomplete but strong) limitation of be pollination usually resulted in a strong reduction of yield. This means that not only self-sterile but also self-fertile fruits clearly depend on insect (bee) pollination. This is because pollen dehiscence of anthers and the receptive period of stigmas do not overlap in time within the individual flowers. Stigmas in self-fertile trees, therefore, need pollen carried by bees from another flowers of the same tree (or compatible pollen from another trees). Accordingly, additional bee pollination (moving bee colonies to the orchards in flower) is needed to all kinds of temperate-zone fruit tree species when bee visitation of plantations is not abundant enough for some reasons.

  • The tests of effectiveness of Frostbuster under excessive weather conditions in an apricot plantation
    87-91.
    Views:
    293

    Frostbuster is a new system, engine and technology, developed to protect fruit plantations from the frost damage. In order to raise domestic experiences and measurements, experimental approach has been initiated to prove the utility of the system under excessively low temperature in the plantation of the Siófoki Gyümölcstermesztési Zrt (Fruit Growing Co. Siófok). The first opportunity ensued in the night of February 23-24, 2011, when the temperature sank to 12°C below zero. The question was to see whether we could prevent the drop of temperature by the frostbuster technique. The margin of an anticyclone staying on East Europe secured a stable condition to make tests. The only difference from the imaginable conditions of dangerous frosts was the heat keeping capacity of trees was weak, much inferior than compared with trees in full boom. As a consequence, the tree rows represented much lower heat-capacity and cooled down much quicker than blooming trees in springtime, i.e. their temperature was more variable. The other difference was, compared with an episode in spring that the hard frost lasted much longer than usually in spring. For testing the system, those conditions had even more advantage. Six meteorological stations helped us in measurement. Data-collectors were timed to 1 minute distances and the bulk of data proved to be beneficial for testing the Frostbuster. The results prove that the system is adequate to keep the temperature continuously higher than the surrounding field under excessively low temperatures. Further measurements are still needed to find the optimal solutions fitting to the growing site and its microclimate. Results presented offer a basis of further proofs.

  • Conditions and outlooks of growing stone fruits
    91-98.
    Views:
    241

    Conditions and outlooks of growing stone fruits

  • Rootstock effects on fruit drop and quality of 'Arlet' apples
    69-75.
    Views:
    297

    The aim of this study is to investigate the effect of different growth inducing rootstocks on fruit drop of apple. This research was conducted for 3 years at Nagykutas, Western Hungary on apple cv. 'Arlet'. For the experiments, 3 different growth inducing rootstocks were choosen: M.9 (weak), MM.106 (moderate) and crabapple seedling (strong). There were 3 fruit shedding periods on the trees grafted M.9 and MM.106 rootstocks, but in the case of crabapple seedling, only 2 were found. The measure of fruit drop was closely related to seed count of fruits; seed number was the lowest, fruit drop was the highest. The lowest seed number was counted in fruits from trees on crabapple seedling. Seasonal changes of leaf:fruit ratio mainly depended on shoot growth and fruit drop. The rise of the curve of leaf:fruit ratio was very important during the first phase of fruit development, in especially at the end of June and in the beginning of July. The cause of this is that first and second periods of fruit drop appeared during this term. The rise of the curve was important in the beginning of June and the end of July on crabapple seedling. Decreasing tendency of quality parameters was found of fruits from trees on M.9, MM.106 and seedling rootstocks, except flesh firmness which was the highest in fruits from trees on crabapple seedling.

  • The Role of Human Factor in the Innovation of Apricot Production-Empirical Study in a Disadvantage Area of East-Central European Country
    131-134.
    Views:
    382

    Hungary is a traditional fruit growing country for ages. As fruit sector has a very high hand work request and value added, it has an important role to decrease the elimination of unemployment and the lack of income in the disadvantage rural areas. The study was made in the year of 2009, the studied population consisted of the members of the fruit-grower marketing organization (Gyümölcsért Ltd.), that organizes growing and sales of stone fruits in Hungary. The number of studied population were 95 capita, the number of fi lled out and evaluated questionnaires was 35. By the composition of the questions both qualitative and quantitative methods have been used. We tried to get answers to the following questions: Are the studied human factors (age, educational level, sex etc.) of growers, determined the extension of innovation of apricot production?

  • Monitoring of water regime in an apple orchard
    29-32.
    Views:
    257

    Our investigation was carried out at an micro-irrigated intensive apple orchard in Debrecen-Pallag in 2010. The aims of the study were to monitor the effect of a compacted layer on soil water regime by tensiometers and supporting the water management of the orchard. The results suggest that the physical characteristic of the examined soil is sandy soil with low capillarity and total available water content. The soil water tensions were varied between pF 0 and 2.5 due to the extreme precipitation circumstances in 2010. Tensiometers in 40 cm depth resulted fast (few hours) and significant respond to precipitation than in the 70 cm soil layer. Based on daily measurements, the soils possess a daily fluctuation of soil moisture, however the changes become more moderate in deeper layers. In accordance with all of the results, the amount of drainable water regime was about 20.6 V/V% at 40 cm depth and 18.6 V/V% at 70 cm mainly. The harmful surplus water can be infiltrated by loosening of the compacted soil layer in 50–70 cm depth or led off by vertical drainage.

  • Terminology of fruit set and fruit drop of sour cherry cultivars
    33-36.
    Views:
    234

    Fruit set and fruit drop rates of 9 sour cherry cultivars (‘Érdi bôtermő’, ‘Debreceni bőtermő’, ‘Kántorjánosi’, ‘Újfehértói fürtös’, ‘Éva’, ‘Petri’ ‘Oblocsinszka’, ‘Pandy 279’ and ‘Csengôdi’) of eight years-old trees grown in Újfehértó, located in the Eastern north part of Hungary which grafted on Prunns mahaleb have been studied. Significant differences have been found in fruit set among cultivars. The average percentage of fruit set was 18.3%, which the ‘Oblacsinszka’ by 32.6% the highest fruit set, while ‘Debreceni bőtermő’ is very similar to ‘Pandy279’ showed lowest (12%) fruit set. Seasonal changes of fruit set and drop shows that there are four abscission peaks. The first fruit abortion wave appears during second week after pollination Thereafter, the second and third dropping period was found during the third and forth weeks after pollination. The forth abscission happened on the forth week after pollination. The highest fruit drop happened on ‘Pandy279’ (92.4%) very similar to ‘Éva’ (90%) while the lowest fruit drop observed in ‘Oblocsinszka’ (71.5%)

  • Association of varieties in stone fruit plantations
    29-33.
    Views:
    203

    In the majority of Hungarian orchards of stone fruits, the planting distance is 6-7 m x 4-5 m. As many of the current varieties are self-incompatible, planting designs are applied to provide for adequate pollinisers. As long as differences in blooming time are small, i.e. 3-5 days at most, overlaps of blooming of the associated varieties are sufficient for fruit set.

    In sour cherry, one leading variety, Pándy, is self-incompatible and requires two polliniser varieties at least (Ciganyneggy or some sweet cherry varieties). Pándy is, moreover, cross-incompatible with the varieties Debreceni bőtermő, Kántorjánosi and Újfehértói fürtös being all of them self-fertile as most of new varieties recommended, by the way, for being planted to monovarietal blocks.

    Among European plums there are varieties registered as male sterile, self-incompatible, parially self-fertile and self-fertile, respectively. For the purpose of cross pollination, the choice of two varieties, at least, to be associated to any variety belonging to the first three groups, is recommended. The number of rows in blocks planted to self incompatible or male-sterile varieties should not be higher than 2-(4). Inter-incompatibility has been observed within the currently recommended assortment, between the varieties Cacanska najbolja and Stanley, only. Chinese-Japanese plums are scarcely represented in Hungarian plantations. Variation of blooming time in varieties is somewhat more pronounced, i.e. 5-8 days. There is but a weak tendency to self-fertility, thus practically, all varieties are considered as self-incompatible, thus the planting of two-row blocks for each of three varieties, at least, are recommended to be associated.

    Self-incompatibility and partially self-fertile apricot varieties are recommended to be combined with two polliniser varieties, at least, each planted to two-row blocks. The varieties Ceglédi óriás, Ligeti óriás, Nagykőrösi óriás and Szegedi Mammut are mutually inter-incompatible. Most of the peach varieties grown in Hungary are self-fertile, thus they are planted to large blocks, each. On sites threatened by late spring frost, it is recommended to plant (monovarietal) blocks of 4-6 rows at most. Cross-pollination may increase fruit set even in self-fertile varieties.

     

  • Irrigation management of a peach orchard
    19-24.
    Views:
    259

    The research field was at Siófok, in Hungary, which is situated in the South East side of Lake Balaton. The physical characteristic of the soil is sandy loam and loam and the peach orchard is irrigated. Mainly Sweet Lady (early ripening), Red Heaven (medium ripening) and Weinberger (early ripening) species were installed. In order to achieve the optimal developement level of trees and maximal yield amount and fruit diameter (Sweet Lady 60–75 mm, Red Heaven 60–70 mm, Veinberger 50–60 mm) continous water and nutrient supply is required. The irrigation modeling was set by CROPWAT 8.0 based on the climatic, crop and soil data inputs of the last 10 years. Based on the results, large amount of water is needed for optimal growth of fruit trees, particularly in the summer months, in case of active ground cover (+) and bare soil (–) as well. The irrigation requirement of a tree was found maximum 4 l/hour in certain cases. This irrigation intensity can be achieved – calculated with 12-hour operating time – by using continuous water NAAN Tif drip tube with 2 l/h flux on 3 atm pressure with 16 mm pipe diameter. If lower irrigation intensity is required irrigation can be controlled by the decreased the operation time.

  • Susceptibility of European pear genotypes in a gene bank to pear psylla damage and possible exploitation of resistant varieties in organic farming
    95-101.
    Views:
    263

    We evaluated 285 pear genotypes (commercial cultivars, ancient local varieties, unnamed local strains, seedlings, wild seedlings) in the largest gene bank of pear in Hungary from the point of view of psylla resistance to explore their possible exploitation in organic farming. We have found some 10 new resistant types (Bókoló körte, Bôtermô Kálmán, Füge alakú körte, Nagyasszony körte, Nyári Kálmán, Rozs nyári körte, Viki körte, Pb-242, Pb-299, 0-632) and 7 highly tolerant ones (Cure-6, Kései Kálmán, Kieffer, Kieffer Éd, Steiner, Téli Kálmán, II. B-3- 6/4, 96-16/5) (Table 1). These made up 3.5 + 2.8 per cent of the investigated genotypes, while 93.7 per cent of them were susceptible to pear psylla damage. Taking earlier and present results into account we can list more than 30 European pear cultivars being resistant or highly tolerant to pear psylla infestation and damage. In fact, the list of resistant and highly tolerant cultivars may serve as a basis selecting pear cultivars fitting to the specific requirements of the organic farming. By the end we can conclude that there is some real hope to exploit some resistant or highly tolerant ancient or local cultivars in organic farming but further investigations are needed to estimate their yield capacity and fruit quality.

  • Fruit drop: The role of inner agents and environmental factors in the drop of flowers and fruits
    13-23.
    Views:
    554

    The basic conditions of fruit set (synchronic bloom, transfer of pollen, etc.) still do decide definitely the fate of the flower (Cano-Medrano & Darnell, 1998) in spite of the best weather conditions (Stösser, 2002). 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 (Soltész, 1997). There are also basically genetic agents in action. 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.

  • Colour and water content detection of sweet cherry by portable spectrometer
    23-26.
    Views:
    323

    Based on the most recent data, the average amount of sweet cherry produced in Hungary is around 10-12 thousand tons. Therefore fast and effective method is important for sweet cherry fruit quality analyses. The aim of the study was to examine the applicability of reflectance measurements for sweet cherry fruit quality analyses. In our experiment five cherry species (Vera, Cristalina, Germersdorfi, Noir de Mechet, Canada Giant) were examined in order to measure the spectral differences between species. Further more, spectral alteration was examined between different health and maturity status of the fruits in the case of a specified, the Germesdorfi species. The four new indices are appropriate tools for cherry quality analysis. Thus reflectance measurements can also support more precise and automated fruit selections. The methods for the differentiation of species could also be viable at a concerned habitat; however, the climate, habitat and soil conditions strongly affect the yield quality. Concerning the fast determination of water content, WBI could be a reliable method for the assessment

  • Climatic indicator analysis of blooming time for sour cherries
    11-16.
    Views:
    208

    County Szabolcs-Szatmár-Bereg produces more than the half of the total sour cherry grown in Hungary. Successful production, i.e. yield, depends largely on weather conditions. Most attention should be paid to the weather during the blooming period, being most decisive from the points of view of quality as well as quantity. In order to predict yields expected, the characterisation of the most important weather parameters is necessary. For that purpose, the database of the Institute of Research and Extension Service for Fruit Growing at Újfehértó Ltd. has been utilised. Records of weather conditions were collected throughout the period 1984-2005, i.e. daily minimum, maximum and mean temperatures (°C), precipitation (mm), and phonological diary of sour cherry varieties ’Újfehértói fürtös’, ’Kántorjánosi’ and ’Debreceni bôtermô’. Data of 7 indicators have been traced: number of frosty days, the absolute minimum temperatures, means of minimum temperatures, number of days when daily means were above 10°C, means of maximum temperatures, number of days without precipitation, and number of days when precipitation was more than 5 mm. On the one hand, we surveyed the changes; on the other hand, estimates have been attempted for the future changes expected during the following decades. The indicators being associated with certain risky events may serve for the prediction of the future recommendations to prevent damages.

  • Hungaricum as a quality of fruits and fruit products
    71-81.
    Views:
    214

    The territory of the Hungarian state is largely suitable for the purpose of growing fruits of the temperate zone species. During the next decennia, the annual volume of Hungarian fruit production is expected to be around 1.1-1.3 million tons, from which some 15% is considered to be a produce of Hungary or "Hungaricum" (90 thousand tons of sour cherry, 50 thousand tons of apricot, 20 thousand tons of raspberry, 10 thousand tons of walnut). These fruits symbolise the country's special quality, which are worth to catch the interest the foreign consumers.

    The category of Hungaricum involves almost exclusively varieties of Hungarian origin as sour cherries, apricots, raspberries and walnuts, and they are representing outstanding qualities on the international markets.

    As for the fruit products the fruit brandies are eligible to be "Hungaricum" and are called exclusively "Pálinka". The Pálinka, provided to be distinguished with a geographic mark and will be competitive on the world market. Smaller quantities, though significant produce is represented by the deep frozen raspberry.

  • Spatial and temporal variation of extremely low minimum temperatures in Hungary during the period between 1951 and 2010
    75-80.
    Views:
    217

    For this study, data of 16 meteorological stations have been processed over a period of 60 years with the purpose to reveal the spatial and temporal structure of the frequencies of absolute extreme minima in Hungary with special reference to the surmised global rise of temperatures on a worldwide scale. In the main areas of fruit growing, the monthly or seasonal absolute temperature maxima and minima are presented during the 60 year-long period and projected on the geographical map. For the main fruit- and vegetable growing regions the probability of winter- and late frosts is of prime interest. The time series of extreme temperatures though did not prove signifi cant changes over the period observed, but the information upon changes and their tendencies is a precious tool being utilised in planning, choice of adequate varieties for a longer period of time in the future. The deleterious winter frosts experienced in fruit production is not a consequence of a sole drop to a minimum temperature, but of an earlier period of mild temperatures during the winter, which sensibilised the trees. Frequent and extreme variations of temperatures may cause troubles at any time during the year and reduce the yields conspicuously. We ought to get familiar with the hazards of our climate and fi nd optimal solutions to mitigate the damages expected. The seasonal and monthly distribution projected on the geographical map we can follow up also the spatial relations and the signifi cance of their occurrence. Coeffi cients of variation between meteorological happenings at different localities facilitate the calculation of the probability of risks on the surrounding areas.

  • Correlation of precipitation distribution and quality sweet cherry production
    39-43.
    Views:
    229

    Sweet and sour cherry need 550–600 mm yearly precipitation. The critical period is 1–1.5 month after flowering, it is normally between 15.April – 15. June in Hungary. The rain induced fruit cracking is also a critical and costly problem for cherry growers. Fruits grown under arid conditions are less resistant against rainfall during harvest and up to 50–60% crack damage may occur. A computer program was developed to calculate the precipitation related production risks of sweet cherry. Focus of the research was Zala county. Spatial distribution of precipitation was compared in two directions (East and North of Zala county) based on the data of meteorological stations. The first results indicate that the developed method estimates the risks quite well, compared to the farm experiment results. The developed computer program can be parameterised according to the user’s requirements, this allows to take into account the real variety structure of a given orchard.

  • The effect of day and night temperatures on apple skin colour formation
    21-25.
    Views:
    255

    The colour of fruits is considered to be an important quality indicator. Saleability greatly depends on how well covered the colour is of the specific type of fruits. It is a well-known phenomenon by growers that apples get nicer colours in one year while in other years the basically red and green colour cultivars can be differentiated only by morphological characteristic features. Cover colour is one of the phenometric variables and it is a well-known fact that significant differences can be experienced year by year. The experienced oscillation can be the cause of inappropriate water- and nutriment supply, however it can be the result of some kind of plant disease, extremely high or low temperature, setting rate above the average and outstanding fruit density. In the present examination it is postulated that the degree of cover colour is mostly influenced by day and night temperature. Therefore, our study aims to find out whether it is true or not. Cover colour belongs to those phenometric characteristic features, only the final value of which is taken into consideration; due to their nature of establishment or forming time it seems useless to follow closely the change in the time of vegetation. However, determining the start of colouring and knowing the dynamics of full colouring could carry very important information for growers. If it is possible to determine the curve describing the time change of colouring, we have a possibility to estimate it by means of enviroment variables. So it is also possible to model pigmentation in the future. Knowing this, colouring irrigation could be made more efficient in the future. For this, as a first step, it is inevitable to find out what the relationship is between the main meteorogical variables, namely day and night temperature and the difference between day and night temperature, and colour cover. In this study we summarize and show these interrelations.

  • Agroclimatological properties of growing sites assigned to apple and pear production in Hungary
    95-97.
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    200

    Apple and pear growing sites in Hungary are classified into four regions according to the Hydro-thermic Coefficient: dry, moderately dry. moderately humid and humid. Most of the plantations of apple and pear are located in regions considered as moderately dry and moderately humid. Within that category, the two respective species have different preferences, i.e. the ecological features of Hungary give different opportunities for apple and pear growing. Apple is grown almost everywhere in the country, successfully. The selection of cultivar-regions is needed mainly for increasing competitiveness on the market. Main apple growing regions are listed in 3 large groups. For the definition of cultivar-regions, mainly the configurations of soil and precipitation, i.e. conditions of the soil and opportunities of gaining water were decisive. Market factors are also considered. The area assigned to pear is much less than that of apple, in Hungary. Some well known and popular varieties would require high air humidity which cannot be presented in most of Hungary. Therefore, the possibility to establish regions for pear varieties is restricted, we have to create a particular micro-environment. Two groups are potential. The first one comprises sites where the annual precipitation is 700 mm, at least. There, apple and pear production would compete each other. In more dry habitats (less than 700 mm annual precipitation), micro-environments should be found and only drought-resistant, mainly summer-ripe cultivars should be chosen with, preferably, low tendency of sclereid formation. In that case, neither irrigation could help to produce adequate quality in varieties sensitive to low air humidity.