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  • The effect of storage to optical properties in case of two apple fruit varieties
    33-36.
    Views:
    235

    The keeping quality of fruits is a very important factor in storage point of view, since it could be elongated the consumption time of fruits. In many cases the storage may be necessary, e.g. in short time it is not able to market due to the rich harvest, or all fruits could sell in markets throughout the year. The keeping quality of various fruit species is greatly different; moreover it could be observed some differences between the varieties as well. In our research, we have investigated the spectral properties of the external surface and fl esh of two ripe apple varieties – Jonagored and Granny Smith – before and after storage (about 3°C and about three weeks). The hyperspectral investigation was carried out with AvaSpec-2048 Fiber Optic Spectrometer. The experimental results represented the differences between healthy and chilling injured apple fruits. Furthermore, some indices were created to given countenance to the spectral differences.

  • Effect of boron nutrition on nutrient uptake and fruit quality of tart cherry in Eastern Hungary
    45-48.
    Views:
    252

    Effect of the foliar boron (B) application on nutrient uptake and fruit quality of tart cherry (Prunus cerasus L.) was investigated from 2008 to 2009 on mature four favourite Hungarian tart cherry cultivars like ‘Oblacsinszka’, ‘Érdi bôtermő’, ‘Újfehértói fürtös’ and ‘Petri’. Tart cherry trees grown in Eastern Hungary (Újfehértó) on an acidic sandy soil with low B content. Trees were treated with B by foliar application (0.5% B) at full bloom and untreated with B served as a control. B sprays strongly affected on B content of inflorescences. However, B sprays had no consistent effect on summer leaf B status. In our experiment stronger year effect was observed at leaf B status than flower B status. The effectiveness of early spring boron applications are limited and mostly affected the flower B status only. Moreover, treatments had inconsistent effect on studied fruit inner parameters. Monosaccharides, vitamin C and organic acid contents of sour cherry were stronger affected by cultivars than applied treatments.

  • Ecological drought resistance and adaptability of apple varieties
    113-122.
    Views:
    301

    For adequate yields in apple plantations, during the long growing period of the fruit primordia, one of the decisive factors is water supply. Indicators of stress are valuable signs for the diagnosis of drought and necessity of watering, i.e. planning the irrigation of plantations. The aim of the present study was to find reliable signs of water stress on apple trees and at the same time conclude on the drought tolerance of different varieties. The plantation of apple varieties grafted on various stocks and cultivated according to different systems (irrigated, non irrigated, integrate and biological) has been examined continuously by leaf analysis. Along the period of growing fruits, measurements were made in the field, then the leaf samples were analysed in the laboratory for composition of pigments, carbohydrates and antioxidants, as well as the histology of the tissues checked. Without irrigation, the mean leaf mass and the relative chlorophyll content (SPAD) of the variety Idared on M4 stocks increases beyond the values of 50 SPAD, whereas on M26 stock and integrated system, it declines. In the collection of varieties, grown according to the „integrated” system, during the development of fruits, ‘Gála’ and ‘Remo’ varieties have been affiliated to the “less susceptible” group regarding drought tolerance because of the leaf morphology, structure and content of SPAD and antioxidants. However, ‘Idared’ and ‘Jonagold’ belong to the “susceptible” group. To the same group are ranged the ‘Akane, Red Rome vanWell, Pink Lady’ varieties. Those varieties reacted to a short period of drought by increased production (content) of carbohydrates. Regarding changes of carbohydrate content ‘Greensleeves’ and ‘Ozark Gold’ varieties belong to the moderately water dependent (requiring) group. In the field, SPAD-tests facilitated the measurement of nutrient-uptake and incorporation, which is proved by the tight correlation between the data of SPAD and the increment of leaf weight (r=0.76–r=0.88), however, this depends on the variety too. SPAD is an indicator of water supply and is related with the density of stomata, cannot used for the selection of water-exigent varieties but for (drought) tolerant ones. In integrated culture, the (drought) susceptible varieties display (water-soluble) hydrophilic and lipophilic antioxidants (ACWand ACL resp.) the quantity of which may have some role in drought tolerance.

  • Antioxidant capacity, total phenolics and mineral element contents in fruits of Hungarian sour cherry cultivars
    59-64.
    Views:
    356

    Several epidemiological studies revealed that the consumption of antioxidant compounds and the risk of atherosclerosis, increased blood pressure or cancer are inversely proportional. Fruits of sour cherry contain a wide range of antioxidant compounds including melatonin, perillyl alcohol, ellagic acid, several flavonoids, polyphenolics, and anthocyanins. This study was carried out to survey the antioxidant power and mineral element content of seven commercial sour cherry cultivars and three cultivar candidates and to assess the influence of some external conditions on fruits' functional properties. Our analysis revealed nearly 5- and 2-fold differences between the lowest and highest antioxidant capacities and total phenolics content, respectively. Some cultivars (`Kántorjánosi' and ‘Újfehértói fürtös') and cultivar candidates (D, 'Petri' and 'Éva') showed outstanding antioxidant capacity and total phenolic content; in addition, mineral element content in fruits of the ‘Újfehértói fürtös' cultivar was also favourable. Redox parameters of fruits were influenced by the cultivation plot or fruit positions within the canopy in about half of the cultivars tested. Genetic background of cultivars forms the decisive factor in determining fruits' antioxidant capacity, although external factors may have also sizeable modifying effects. Enhanced functional properties of the fruit may also be further increased through breeding programs since considerable variation exists within the tested germplasm.

  • 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.

  • Bee pollination and association of apricot varieties
    20-24.
    Views:
    191

    Apricot yields are highly variable according to the season. The variation is caused mainly by the adversities during the critical processes of floral biology, i.e. blooming and fertilisation. On the basis of information concerning blooming time and mutual compatibility relations of apricot varieties a system of securing regular and adequate yields has been developed.

    Winter frosts of the continental type are well tolerated by most of the apricots, however, after the end of rest period, flower buds are loosing frost tolerance, 'rapidly.

    Being one of the fruit species blooming earliest during the early spring, apricot start to bloom in Hungary around the end of March or early April as a mean of many years, but it also happened, exceptionally that apricot started to bloom at February 20 (at Letenye South Hungary). The early season, exposes the floral organs to frost injuries. As a consequence, apricot orchards on the Great Plain produce low yields in 3 years, intermediate yields in other 3 years out of a ten-year-period.

    Moreover, weather conditions during the blooming period are often unfavourable for pollination. Cool, windy and rainy weather prevents the flight of insects and on the other hand, warm spells shorten the blooming process, nectarines and stigmata get dry and the female gametes loose viability before effective pollination occurres.

    The fertility of individual cultivars are meeting different obstacles. Apricot cultivars differ greatly in the rate of flowers bearing underdeveloped pistils, which may attain even 60% (e.g. Orangered). New commercial cultivars are often self-incompatible. Local varieties of that type in Hungary are the „óriás" varieties (e.g. Ceglédi óriás, Szegedi mammut), and the new hybrid Ceglédi Piroska. Many of the cultivars are variable in their self-fertility (partially self-fertile): Budapest, Harmat, Korai piros, Mandulakajszi.

    Inter-incompatibility is also known in apricots. The „óriás " varieties do not fertilise each other. During the growth of fruits, cool spells (2-4 °C) caused severe fruit shed in Ceglédi óriás.

    Apricot flowers produce pollen and nectar at average rates related to other fruit species, thus bees are attracted sufficiently. Bee visits are very variable according to growing site and season. Most of the bees are pollen gatherers but sometimes nectar suckers are in majority. Bee pollination is necessary not only for the self-incompatible varieties but also to enhance the yield of self-fertile varieties.

    Taking the blooming and fertility relations of the cultivars into account, plantations should not exceed two rows to a particular self-incompatible varieties, and possibly two different polliniser varieties are suggested to be planted as flanking the block in question.

    In commercial plantations 2 to 4 bee colonies per hectare are proposed to move for the whole blooming period.

     

  • Economic figures of apple production at national level of Hungary
    103-105.
    Views:
    240

    Apple is the most important fruit in Hungary, despite of that, it is a paradox that during the last years, apple growing was the most unsuccessful enterprise among the prosperous ones in the country. The real cause of regression was unequivocally the low price, which could be obtained and the inadequate structure of apple varieties. A heavy problem is still the overweight of the quality doomed to supplying the processing industry instead to the fresh consumption. In order to improve the conditions, we aimed the economic analysis of the five year long period, 2005-2009, to trace the changes involving values and costs of production, income and all conditions combined with this activity. The data presented in the paper are means of a heterogeneous population of values, which cannot be utilised for immediate use in management, but they may reveal the challenges and tendencies of that branch in economics.

  • Extreme weather events inWest Hungary
    29-32.
    Views:
    229

    Agricultural production is a rather risky activity, as it is largely exposed to extreme weather events. This paper focuses on the frost and hail data in springtime, affecting fruit production in West Hungary. Regarding absolute minimum temperatures in April, significant increase of the standard deviations could be observed. Among the sites examined Nagykanizsa shows the highest risk values. According to our evaluation Nagykanizsa is not recommended to plant sour cherry, sweet cherry and apricot orchards because in some years spring frost will occur. If the plantation is in Zalaegerszeg, Szombathely, Gyôr or Keszthely than usage of frost prevention system is recommended. Siófok is the only area to grow apricot with good result.

  • Assessment of apple varieties based on consumer judgement on their fruits of organic production for fresh consumption
    87-90.
    Views:
    202

    The lack of information is often cause of the insufficiency of attributes being developed and appears on the new commodity characterising its utility. Neither own nor other information is presented. For improving this handicap, we endeavoured to praise apple products grown by biological methods and explain their properties as taste, skin, colour, consistency, and size. In addition, we explore the relation between general impression and the individual properties. The scrutiny starts with collecting of primary data on 9 samples taken from biologically grown apple varieties kept over 60–90 days in a store and offered to the consumers. The test is based on an organoleptic assessment (records are registered in a questionnary). The individual judgements are processed and coefficients of correlation between the traits (taste, skin, size, colour) calculated. The validity of the mathematically proved relations is considered to be decisive judging the preferences in consumption of fruits.

  • 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.

  • The new era of horticultural production after the millennium
    87-90.
    Views:
    157

    The horticultural branches turn out, in relation to their area, a very great production. value. At the same time' many useful jobs are created. The development of gardening is, therefore, an important interest of our national economy. To the continuous enhancement of quality and quantity belongs the alloyage of new methods (biotechnology, integrated and organic procedures) with our traditional feats and with the incessant raise of the professional level.

     

  • Damages caused by winter frosts, their temporal variation and frequencies in the main fruit growing region of Transdanubia and of the East Tisza regions of Hungary
    89-97.
    Views:
    200

    The aim of the study was the study of winter frost damages, especially their changes expressed in temporal frequencies on the main fruit growing regions of the country. In our earlier paper, we introduced the calculation with the term LT50 as the quantitative expression of temperature threshold, when the lethality halves the survival of plant organs, buds or cells causing 50% death rate. The damage is highly dependent on the temperature and on its duration (length of time), but not at least on the frost tolerance of the fruit trees. The incidence and severity of damage is analysed according to the apricot and peach varieties of their different susceptibility or tolerance too. Four fruit growing regions, two of the in Transdanubia and two belonging to the regions east of the Tisza river have been selected to trace the incidence and severity of frost damages. For that purpose, we analysed the history of the past 60 year period, 1951–2010, utilising the database of the network of 16 meteorological stations of the countrywide service. Being aware of the values of LT50 during the rest period and afterward, the compulsory dormancy caused by low temperature, the number of days, the probability of frost damage could be predicted. The role of the orographical profi le, the height above sea level and the exposition of plantations are also decisive. Within the same plantation, 20–30 m difference of level may cause large diversity in temperature and frost damage. Air circulation and regular incidence of winds within the Carpathian basin modify the occurrence and severity of damages. Lowlands near the southern and northern country borders are particularly exposed to winter frosts. Most damages are reported in February, as temperatures below –20 °C especially if the fi rst part of the winter was mild, or in January was a warm period. With the end of the physiological rest period of the trees, the frost-susceptibility increases signifi cantly, and a cold period of –15 °C may cause heavy damage. This study proves that tolerance of varieties infl uence the damages substantially. By planting frost tolerant varieties, winter frost damages could be diminished by 40–50% at the same growing sites. Present results may also offer a tool to estimate the risk of frost damages and express the security of yields at a given site based on the data accumulated in the database over many years.

  • Effect of organic and integrated farming on carotenoid and tocopherol content of apricot fruits
    15-18.
    Views:
    203

    In modern and healthy diets antioxidants play an important role providing natural defence against serious diseases. Therefore it is recommended to include fruits and vegetables having high antioxidant capacity in daily diet in a due course. Apricot is one of the fruits receiving an increasing attention in this field. This study was conducted to investigate the composition and content of fat-soluble carotenoids and tocopherols in different varieties of apricot using recently developed liquid chromatographic methods. Also it was aimed to compare organic and integrated farming in their effect on carotenoid and tocopherol content of the fruits. The results showed that apricot fruit are rich in vital carotenoids and bioactive tocopherols with significant variation between different varieties. The organic farming had favourable effect on the level of the major carotenoids and depending on variety this technology either increases or does not have significant influence on vitamin E content.

  • Organoleptic evaluation of pear varieties grown at different sites
    33-37.
    Views:
    226

    It was stated as a summary that a system of testing pear varieties on scale of 100 degrees, weighing 11 properties, gives a comprehensive information on qualities of pear varieties. The points of the form to be filled out, distinguishes the appreciation of accessory flavours and tastes from the main properties. Under the title of taste, sweet and acid taste are evaluated separately. The presently used system is a step forward as the composed characters do not influence the judgement of each other. In the representation of results, the 100 degree system was more efficacious than the usual 5-point system because there was no need of using fractions, and the graphic profile is more expressive, so the commodity is better visualised. The assembly of the jury was divided into two groups as below and above 35 year old persons. The two groups judged differently the acidity, sweetness and the thickness of the fruit peel. It was suggested that the choice of the produce should consider the differences in taste and give up the idea of being equally favourable for both groups. The samples of different growing sites revealed that the best quality is produced at Nagykanizsa, and this capacity would be able to supply the market also in the large super-markets and chain of department stores in Hungary.

  • Relationship beetwen the phenological features of pear cultivars and the main meteorological parameters in a gene bank with 555 pear
    59-63.
    Views:
    171

    The trees observed are grown at Ujfehert6, Eastern Hungary in a gene bank with 555 pear cultivars. Each of the cultivars was monitored for its dates of: the beginning of bloom, main bloom and the end of bloom and ripe phenophasis separately between I 984 and 2002. We analyzed the statistical features, frequency, distribution of these phenophasis and its' correlation the meteorological variables bet ween the interval. During this period the meteorological database recorded the following variables: daily mean temperature (°C), daily maximum temperature (0C), daily mini m um temperature (0C), daily precipitation (mm), daily hours of bright sunshine, daily means or the differences between the day-time and night-time temperatures (0C). For the analysis of data the cultivars have been grouped according to dates of maturity, blooming period as well as types of the seasons. Groups of maturity dates: summer ripe, autumnal ripening, winter ripe cultivars. Groups of blooming dates: early blooming, intermediate blooming, late blooming cultivars. At all the separated groups we analyzed the relationship between phenophasis and meteorological variables. During the 18 years of observation , the early blooming cultivars started blooming on 10-21 April, those of intermediate bloom date started flowering bet ween 20 April and 3 May, whereas the late blooming group started on 2- 10 May. Among the meteorological variables of the former autumn and winter periods, the winter maxima were the most active factor influencing the start dates of bloom in the subsequent spring. For the research of fruit growing-weather relationships we used simple, well known statistical methods, correlation and regression analysis. We used the SPSS 1 1.0 software for the linear regression fitting and for calculation of dispersions as well. The 1ables made by Excel programme.

  • Microclimatic studies on different aged apple plantations
    7-11.
    Views:
    189

    The purpose of measuring parallel canopy and out of canopy microclimates was to find out in what extent climatic parameters measured in different aged canopis differ from each other and from the values characteristic to out-of-canopi areas. The importance of phytoclimatic researches seems to lie in the fact that if the reactions of fruit trees towards meteorological elements are continuously followed, we have the possibility to provide growers with information. These pieces of information are like defining the optimum time of phitotechnical interventions (summer pruning, sorting sprouts, thinning fruits, etc.), the necessity of applying mulching, defining the method and time of irrigation and applying plant protection activities. By means of phytoclimatic researches, it is possible to react to unfavourable meteorological impacts within a certain extent. It is also possible to successfully reduce the risks of late spring and early autumn frost damage, as well as the risks, content and measure of experienced heat and water stress conditions by finding out about the physical characteristics of the canopis' internal area.

  • Variability of the data indicating the fertility of different plum varieties
    51-55.
    Views:
    156

    Self-fertility and fertility at conditions of open pollination in plum varieties is strictly determined by genetic factors. However, rates of fruit set are highly variable according to growing sites as well as to seasons, which may result from a couple of inner and outer conditions, but mainly from the method applied in seizing the facts of fertility in the experiments planned including the number of replications of treatments. During three successive years, 4-16 trees of each of the four plum varieties have been selected and 16-64 branches were tagged either for checking their fertility as pollinated freely or isolated excluding the access of foreign pollen. The data of fruit set have been processed in order to determine the variability of the data, subsequently, the number of replications necessary to make reliable decisions. Both autogamy and open pollination displayed multiple differences between branches and trees studied.

    A number of 20 branches are needed yearly for each variety, the branches should be distributed on 5 trees at least for checking the autogamy, whereas on 10 trees for the results of open pollination. Each variety and treatment should be represented in three seasons, at least because of the different weather conditions.

  • Inter-incompatibility of self- incompatible apricots and their varietal properties
    79-81.
    Views:
    166

    There are four apricot varieties grown in Hungary derived from local selections known to bear fruits of giant (60 - 100 g) size: Ceglédi óriás, Nagykőrösi óriás, Szegedi mammut and Ligeti óriás. Being morphologically similar, they seem to be closely related to each other. The detailed study of the morphology (of leaves and fruits) and phenology (of blooming and ripening dates) as well as the fertility relations was aimed to find out the degree of kinship between the varieties in question.

    It was stated that the value of morphological traits is variable from the taxonomic point of view. The most important signs of common origin were the time of blooming and the leaf size. Less valuable are the date of m:iurity and the size of fruit because of their variability. In the literature Satin') & Nyeki (1991) published the first proof of inter-incompatible relation between apricot varieties. This should be considered as an argument of close genetic relation between those "giant" varieties of apricots.

    The first three varieties. Ceglédi óriás, Nagykőrösi óriás and Szegedi mammut are closer related in blooming and ripening date, as well as in size of fruit to each other than the variety Ligeti óriás.

     

  • Levels of some micronutrient in dried and fresh fruit samples of apricot cultivars
    25-30.
    Views:
    311

    Concentration of Boron (B), Copper (Cu), Iron (Fe), Magnesium (Mg), Manganese (Mn) and Zinc (Zn) was analyzed in fresh and dried fruit samples of “Jumbo cot“, “Tom cot“, “Gold strike“, “Gold bar“, “Bergeron“, “Bergrouge“, “Sweet cot“, “Yellow cot“ and “Zebra“ apricot cultivars. Concentration of the studied elements was strongly affected by cultivars. B, Cu, Fe, Mn and Zn content of “Tom cot“ was significantly higher than other cultivars. “Gold strike“ had the highest amount of Mg. Similar tendency was observed in “Zebra“ and “Sweet cot“ where Mn content was significantly higher than the other element contents.

  • Preliminary evaluation of breeding perspectives of Ukrainian sweet cherry cultivars: nutraceutical properties and self-incompatibility
    7-11.
    Views:
    306

    Some traditional sweet cherry cultivars of Ukrainian origin may represent perspective material for Hungarian cherry breeding. A total of eight cultivars analysed represent great diversity in several phenotypic traits including fruit ripening time or fruit flesh colour. Considerable differences in the anthocyanin content may result in different antioxidant capacity of fruits. In the present study, we used ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) assays to characterize fruits’ nutraceutical properties. These values were compared with the respective values measured for eight commercial cultivars grown in Hungary. The average of FRAP and TPC values was higher for the Ukrainian cherries compared with commercial cultivars suggesting they might be included in functional breeding programs. Since, cherry is a self-incompatible species, the determination of S-genotype is required for both breeding and successful cultivar association in commercial orchards. Complete or partial S-genotypes were determined for 5 and 3 cultivars, respectively.

  • Analyses of Hungarian sour cherry germplasm with simple sequence repeat markers
    27-31.
    Views:
    198

    Twenty-four sour cherry cultivars (genotypes), belonging to four cultivar groups were fingerprinted using microsatellite markers. All genotypes have been arisen from the Carpathian basin, which could be secondary gene centre of sour cherry, since its progenitor species, ground cherry and sweet cherry overlap here. Five SSR primer pairs, earlier used for fingerprinting Turkish sour cherry germplasm were tested. None of the five primer pairs showed any polymorphism within the cultivar groups. The primer pairs were able to distinguish between the cultivar groups. The Oblacsinszka and the Cigánymeggy cultivar groups were the most difficult to separate, while the Pándy cultivar group was the most distinguishable.

  • High antioxidant - and anthocyanin contents of sour cherry cultivars may benefit the human health: international and Hungarian achievements on phytochemicals
    45-47.
    Views:
    316

    Evidence suggests that a diet with high fruit and vegetable consumption may decrease the risk of chronic diseases, such as cardiovascular diseases and cancer, and phytochemicals including phenolics, flavonoids and carotenoids from fruits and vegetables may play a key role in reducing chronic disease risk. Recent research has proved that sour cherry (Prunus cerasus L.) is a valuable natural source of some bioactive compounds important in human health preservation. According to the published data, the most important biological effects of sour cherry are connected — directly or indirectly — to their endogenous antioxidant behaviour as well as to their specific pattern of anthocyanin components. In the present work, we measured the total antioxidant capacity of some Hungarian sour cherry varieties in combination with their anthocyanin-, and vitamin-C content. In 2003, twelve clones were selected and grafted from a local sour cherry population called "Bosnyák" sour cherry grown in small home gardens and farms of the village Csengod (Great-Plain Region, South Hungary). Other Hungarian sour cherry varieties, i.e. cv. Újfehértói fürtos, cv. Érdi bőterrnő, cv. Debreceni bőterrnő, cv. Csengődi and cv. Kántorjánosi served as a control.

  • Nectar production of pear (Pyrus communis L.) cultivars
    67-75.
    Views:
    232

    Detailed studies were made on the nectar production of 44, 16 and 18 pear cultivars, respectively, in a cultivar collection of pear during three consecutive years with highly different weather in the blooming. Results clearly show that pear does not necessarily produce small amount of nectar as stated in the world literature. In fact, pear can produce extremely high amount of nectar sometimes much higher than other temperate zone fruit trees species but its nectar production is highly subjected to weather, first of all to air temperature. Low nectar production seems to be more frequent than high one and cold weather can prevent its nectar production at all. On the other hand, results corroborate to the earlier statements on the low sugar concentration of pear nectar. There is a highly significant negative correlation between the amount of nectar produced by pear flowers and its sugar concentration (r = -0.52, n = 291, p< 0.001 for 1996, r = -0.34, n = 197, p< 0.001 for 1998). Sugar concentration in individual flowers may be up, to 40% in exceptional cases but generally it is well below 20%. Very high figures for sugar concentration in pear nectar at the literature seem to be incomprehensible. In contrast of some earlier statement in the literature no real difference could be established in the nectar production of pear cultivars, based on much more measurements than in earlier studies. Very low sugar concentration in pear nectar can explain the fact that the overwhelming majority of honeybees are pollen gatherers at pear trees even in the case of exceptionally high nectar production.

     

  • Comparison of honeybee behaviour in blooming fruit plantations
    147-151.
    Views:
    191

    Field observations were made on the fl ower visiting behaviour of honeybee foragers in commercial fruit plantations of apricot, Japanese plums, sour cherry, apple and pear. The number of inspected cultivars was 18. The intensity of fl ower visiting by honey bees was markedly different when data of different fruit species are compared. Most intense bee activity was registered on the Japanese plums, somewhat less on apricots, the intensity diminished signifi cantly with apples and pears. Our data presented on the honeybee visitation of Japanese plums can be regarded as new fi nding because no information has been available so far on the relative attractiveness of this fruit species compared to European fruit tree species. Japanese plums were somewhat more attractive to honeybees than apricot and much more attractive than sour cherry, apple and pear. The behaviour of honeybees as visiting the blooming trees displayed specifi c differences according to the fruit species (apricot, sour cherry, pear), which coincide largely with earlier results. It is notable that the fl ower visiting behaviour of honeybees on Japanese plums has been found to be fairly similar to the same on European plums.

  • Applicability of 3D laser scanning in precision horticulture
    55-58.
    Views:
    319

    Due to the technological development, remote sensing instruments and methods have become widespread in all segments of life (from precision agriculture through architecture to medicine). Among the innovative development of remote sensing instruments the 3D laser scanner is of outstanding importance. Horticultural applicability of terrestrial laser scanning technique is a new innovation in the precision agriculture. The structure of trees and branches, the canopy extension, the fruit yield, which can help to recognize some biophysical parameters, can be determined. The examination was carried out with Leica ScanStation C10 terrestrial laser scanner in the Study and Regional Research Farm of the University of Debrecen near Pallag. In this article the measuring principle, the parameters and horticulture applicability of the terrestrial laser scanner are presented.