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  • Concentration of ‘Oblachinska’ sour cherry juice using osmotic distillation
    31-34.
    Views:
    228

    Sour cherry is one of the most famous and characteristic Hungarian fruit what is also commonly used in food production as a colour additive. The sour cherry cultivar, ‘Oblachinska’ was shown to be a rich source of antioxidant compounds, including mainly anthocyanins. Valuable compounds in fruit juice – vitamins, polyphyenols etc. –are heat-sensitive molecules, which should be taken into account during the process of concentration to prevent degradation. Osmotic distillation seems a suitable option to product high quality sour cherry juice because this process does not require high temperature or pressure. Raw juice with approximately 15°Brix was used for the experiment and tried to concentrate up to 60° Brix where the water activity low enough to inhibit the microbiological deterioration. Before and after the process, TPC (total phenolic compounds) and FRAP (ferric reducing antioxidant power) was measured using spectrophotometric methods to determine the effect of the osmotic distillation. Our results point out that osmotic distillation is a promising method to concentrate sour cherry juice and prevent the loss of valuable compounds.

  • 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:
    229

    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.

  • Blooming phenology and fertility of sour cherry cultivars selected in Hungary
    33-37.
    Views:
    156

    Experiments were conducted during the period between 1972 and 2002 at three sites in Hungary. At Érd 97, Helvetia 10, and Újfehértó, 3 cultivars were studied in variety collections. Observations were made on the blooming phenology (start, main time, end and length of the bloom period), on the blooming dynamics (the rate of the open flowers counted every day), on the receptivity of sexual organs, on the fruit set following self- and open-pollination and on the effect of association of varieties in the orchards (choice, rate and placement of pollinisers).

    Based on the results the rate of the overlap of the blooming times were calculated and varieties were assigned into five bloom time groups according to their main bloom. Self-fertility conditioned by natural self pollination was studied and good pollinisers were chosen (sweet, sour and duke cherry varieties) for the self-sterile and partially self-fertile varieties.

    The necessity of bee pollination was proved by different pollination methods: natural self-pollination, artificial self-pollination, open pollination. Summary: Experiments were conducted during the period between 1972 and 2002 at three sites in Hungary. At Érd 97, Helvetia 10, and Újfehértó, 3 cultivars were studied in variety collections. Observations were made on the flowering phenology (start, main time, end and length of the bloom period), on the flowering dynamics (the rate of the open flowers counted every day), on the receptivity of sexual organs, on the fruit set following self- and open-pollination and on the effect of association of varieties in the orchards (choice, rate and placement of pollinisers).

  • Effect of boron nutrition on nutrient uptake and fruit quality of tart cherry in Eastern Hungary
    45-48.
    Views:
    249

    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.

  • The role of meteorological variables of blossoming and ripening within the tendency of qualitative indexes of sour cherry
    7-10.
    Views:
    213

    We analyzed the relationship to sour cherry quality parameters of average temperature, maximum temperature, minimum
    temperature, night and day-time temperature, precipitation and climatic water balance variables. Three cultivars of sour cherry were included
    in the selection: “Debreceni bôtermô”, “Kántorjánosi”, and “Újfehértói fürtös”.We conducted regression analyzes on the three varieties, but
    present only those that proved to be the best fit.We couldn’t find any significant differences in the weather tolerance of the varieties. The data
    base of sour cherry quality parameters covers the 1998 to 2008 intervals. The researched parameters were the following: dry matter content
    (%), sugar content (%), C-vitamin (mg), total acid content (%). Maximum temperature, the difference of night and day-time temperature and
    minimum temperature all have a significant correlation with the investigated quality parameters of sour cherry. Minimum temperature shows
    a quadratic relationship with sugar content, while night and day-time temperature differences show the same with dry matter content. The
    other weather parameters had a linear correlation with the quality parameters of sour cherry. The research results show that an increasing
    amount of precipitation causes decreasing tendency in total acid content of sour cherry, so that increasing temperature has a positive influence
    on total acid content. Big differences in night and day-time temperature also has positive effects on the dry matter and sugar content of sour
    cherry while the amount of precipitation has a negative effect. High minimum temperatures cause decreasing sugar content respiratory energy
    losses are significant if dawn temperatures do not drop considerably.A more favourable climatic water balance has a positive effect on vitamin
    C content in cases of a large negative water balance, vitamin C content is generally low.

  • Relationship between several meteorological factors and phenological features of pear cultivars
    67-73.
    Views:
    194

    The aim of this paper was to investigate the fl owering characteristic of apples and their relationship to meteorological parameters. The trees observed are grown at Újfehértó, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple varieties. Each of the varieties were observed as for their dates of subsequent phenophases, the beginning of bloom, main bloom and the end of bloom over a period between 1984 and 2001 during this period the meteorological data-base keeps the following variables: daily means of temperature (°C), daily maximum temperature (°C), daily minimum temperature (°C), daily precipitation sums (mm), daily sums of sunny hours, daily means of the differences between the day-time and night-time temperatures (°C), average differences between temperatures of successive daily means (°C). Between the 90th and 147th day of the year over the 18 years of observation. The early blooming varieties start blooming at 10–21April. The varieties of intermediate bloom start at the interval 20 April to 3 May, whereas the late blooming group start at 2–10 May. Among the meteorological variables of the former autumnal and hibernal periods, the hibernal maxima were the most active factor infl uencing the start of bloom in the subsequent spring.

  • First results of varios sour cherry cultivar on Oblacsinska as interstocks and Prunus mahaleb rootstocks
    87-90.
    Views:
    232

    At the experiment orchard of the Fruit Research and Extension Institute, Újfehértó, Hungary in spring 2000 a trial was designed included: Erdi bőtermő, Debreceni bőtermő, and Csengődi sour cherry (Prunus avium L) cultivars which were budded at 1999 on Oblacsinska sour cherry (as a dwarf inter stock), which had been budded on Prunus mahaleb seedlings at 1998 with the aim to investigate the dwarfing effects of Oblacsinska sour cherry cultivars on scion cultivars. Trees of each cultivar directly on Prunus mahaleb seedling, severd as controls. Use of Oblacsinska as an interstock reduced the rootstock trunk diameter. Trees of Debreceni bőtermő, and Cseng6di sour cherry cultivars with Oblacsinska interstock were smaller than similar trees grafted directly onto Prunus mahaleb as a rootstock. Trees of Erdi bőtermő grafted on Oblacsinska interstock which buded on Prunus mahaleb were the smallest. Growth of the trees was reduced also by using of the Oblacsinszka as interstock for other examined cultivars.

  • Time of flowering and fertilisation of quince varieties
    9-15.
    Views:
    232

    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.

     

  • The atmospherical drought as a decisive factor of yield in the main sour cherry varieties of Hungary
    121-125.
    Views:
    181

    Atmospheric drought causes heavy diffi culties of water supply in most fruit species grown in Hungary, although the modern, intensive plantations are already equipped with irrigation. The use a dripping systems are widely applied, therefore nothing was done to avert the risk of atmospheric drought. In excessively dry seasons the reduction of yields is often due to atmospheric drought. Present study aims to utilise measured data of meteorological parameters (relative air humidity and temperature) to develop an index to characterise drought and measure its effect on fruit yield. Causes influencing yields are multiple. Phytosanitary problems are combined with defi cits of water supply. Water deficit of the soil is avoided by dripping irrigation, but the atmosphere is infl uenced by sprinklers only. Atmospherical drought increases the transpiration of the trees intensely and causes reduction of photosynthetic activity, consequently impairs the yield. Applying the index developed in a plantation of 6 sour cherry varieties grown in Hungary (Meteor, Nefris, Pándy, Újfehértói fürtös, Kántorjánosi, Debreceni bôtermô), we measured the specific yields (yield per volume of tree crown) during the period 1989–2011 using the meteorological database of the growing site. Additionally, other parameters characterising the drought are compared and searched for a method most reliable for judging the specific yielding capacity of sour cherry varieties. The results proved convincingly the utility of the index, especially for the varieties Pándy and Újfehértói fürtös. Comparison with other indices expressing the effects of drought revealed the superiority of our index, which will be applied in the future to express the risk of atmospheric drought.

  • Apple allergens as affected by cultivation technolog and variental factors
    91-93.
    Views:
    208

    Our objective was to study the effect of organic farming and area of cultivation on the allergen content of apple varieties by quantification of the major allergens (Mal d 1 and Mal d 2) using allergen-specific ELISA. The obtained results showed that except Idared IX. 29. most of examined varieties, when cultivated under organic farming conditions, contained lower level of Mal d1 allergen than those produced with integrated farming. The different varieties were found to vary substantially in theirMal d 1 allergen content. Furthermore, with some varieties the area of cultivation affected to some extent the content of Mal d 1 allergen.

  • First evaluation of fruit quality of some new and old sour cherry cultivars in Hungarian climatic condition
    37-43.
    Views:
    244

    Indeed, in the last decade a large number of new sour cherry cultivars with new notable flavor characteristics have been released. There is no enough information related to qualitative characteristics which consistently segregated based on their predominant sensory characteristics. The present study carried out at tow consecutive years (2008 and 2009) and examined some qualitative characters which are the main importance in the specialty cherries trade, The main objective was to determine fruits quality of Érdi bőtermő, Oblacsinszka, Debreceni bőtermő, Csengődi, Pándy 279, Éva, Kántorjánosi, Újfehértói fürtös and Petri sour cherry cultivars. Changes observed in major characteristics such as fruit detachment force, width, length, weight, peduncle length, flesh firmness, brix, citric acid, Suger/acid ratio and pit weigh.While observed no change in flesh/pit ratio and Coordinate of colour (X*, y*, x*), hue angle and chroma value, in different years. In all measured factors, there was significant difference between selected cultivars of sour cherry fruit. Debreceni bőtermő showed higher values of fruit detachment force in 2008, while had the lover of fruit detachment force in 2009. Fruit firmness of “Érdi bőtermő” were monitored at lover value in both 2-year.

  • The Hungarian pear germplasm as source of genetic variability for breeding programmes
    7-13.
    Views:
    201

    TheHungarian pear collection (Pyrus communis L.) consists of 423 genotypes distributed over seven genebanks inHungary. This is one of themost extensive collections of native and cultivated pears found in Eastern Europe and includes a wide range of genotypes with small size fruit (referred to as “Miniature pears”). Based on the in situ and ex situ measures taken by governmental and other institutions for fruit tree conservation in Hungary, an overview is given on some activities regarding areas of Pyrus collection and genebanks where pears are collected and grown. Descriptions of traits of miniature pears found in Hungarian genebanks for the interest of genetic characterization and breeding are presented.

  • Effects of weather characteristics on blooming dates in an apple gene bank plantation between 1984 and 2001
    37-44.
    Views:
    187

    The aims of this paper was to investigate the flowering characteristic of apples and their relationship to meteorological parameters. The trees observed are grown at Ujfehert6, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple varieties. Each of the varieties were observed as for their dates of subsequent phenophases, the beginning of bloom, main bloom and the end of bloom over a period between 1984 and 2001. During this period the meteorological data-base keeps the following variables: daily means of temperature (°C), daily maximum temperature (°C), daily minimum temperature (°C), daily precipitation sums (mm), daily sums of sunny hours, daily means of the differences between the day-time and night-time temperatures (°C), average differences between temperatures of successive daily means (°C). Between the 90th and 147th day of the year over the 18 years of observation. The early blooming varieties start blooming at 10-21 April. The varieties of intermediate bloom start at the interval 20 April to 3 May, whereas the late blooming group start at 2-10 May. Among the meteorological variables of the former autumnal and hibernal periods, the hibernal maxima were the most active factor influencing the start of bloom in the subsequent spring.

  • The application of A HEAT SUM MODEL for the budburst of sour cherry varieties grown at Újfehértó
    105-112.
    Views:
    258

    Experiences of the last decades showed univocally that the climatic changes, especially the warming up, influenced clearly the phenology, i.e. speed of growth and development of plants. To check the effects, the phenological studies became a topic of special interest. Our research has been performed at Újfehértó, the Research Institute of Fruit Growing and Extension, where the respective database accumulated observations during the period 1984–2005, where the meteorological data as well as the parallel phenological diary referring to the varieties ’Újfehértói fürtös’, ’Kántorjánosi’ and ’Debreceni bôtermô’ during the period 1984–1991 have been utilised. The method of calculating the sum of daily mean temperatures, “degree days”, is based on the observation that the plants are able to utilise cumulatively – in growth and development – the temperature above a set basic temperature. Our phenology model examined the correlation between the sum of degree days and the date of sprouting (budburst). The basic temperature has been determined by optimization, above which (threshold temperature) the accumulation of daily means was most active, or alternatively, below which the daily means are most sensitively expressed in the phenology. The model has been extended to the calculation of the end of rest period (endodormancy) – by optimization as well. Our phenology model will be suitable for two main purposes: for estimating the time of budburst for the Hungarian region during the next decades calculated on the basis of regionally downscaled climate models; on the other hand, by applying our model, the risk of damage caused by spring frosts could be estimated more exactly than earlier.

  • Evaluation of sour cherry varieties grown with environmental technology
    39-41.
    Views:
    420

    The evaluation of a produce is an important moment of predicting its success on the market. The general impression, which is decisive, when a consumer chooses to purchase the commodity, should be interpreted in more objective, measurable terms. Primary data have been collected on fresh fruits derived from different growing technologies by organoleptic tests and the data filled up in the forms are processed with correlation analysis. The components were: taste, aroma, flesh firmness. The coefficients of correlation showed that the rest of characters as the appearance, juiciness, and the sugar/acid ratio.

  • Seasonality of weather and phenology of reproductive organs of flower of sour cherry cultivars in Hungarian climatic conditions
    75-80.
    Views:
    189

    Sour cherry (Prunus cerasus L.) is one of the most important fruit crop grown in Hungary, The flowering phenology and pollen shedding/stigma viability ratio, in an effort to elucidate the reproductive phenology of nine economically important sour cherry cultivars (Érdi bőtermő, Debreceni bőtermő, Csengődi, Kántorjánosi 3. Pándy 279. Úfehértói fürtös, Petri, Éva, and Oblacsinszka) all widespread in the Hungary, was studied at Újfehertó climatic condition. The main aims were to investigate how possible environmental cues influence timing and development of phenophases and whether different cultivars have different seasonal responses to these cues. Likely effects of climatic changes on phenological development patterns were also considered. Our results revealed important aspects of the reproductive biology of sour cherry flowers. The amplitude of the phenophase "beginning of blossoming" between cultivars did not exceed 6 days. There is maximum 3 days difference in blooming length of different direction in each cultivar. Pándy 279 showed high variability when the position of flowers changed on the tree shoots. Újfehértói fürtös was stable in all four directions of tree. The pollen shedding period and stigma viability ratio was well synchronous. Pollen shedding phenomenon occurred in the range limitation of secretary activity of stigmas in all five cultivars. Distribution of pollen shedding over the secretary activity of stigmas is almost good. In all five cultivars maximum pollen shedding occurred about the high temperature part of the day.

  • Flower characters and self-fertilization capacity in relation to the bee pollination at sour cherry cultivars
    121-132.
    Views:
    147

    Detailed studies and comparisons were carried out on those flower characters of sour cherry cultivars that may affect bee pollination of flowers. Flower characters of sour cherry are fairly similar to other temperate zone fruit tree species. Their relatively small flowers distinguish the Cigánymeggy-types of cultivars from the flowers of tart cherries cultivars that are conspicuously larger, almost as large as the sweet cherry flowers. The relative position of flower organs was much more variable according to the season than according to the cultivars. So the differences were rather the consequences of seasonal effects than of variety features of sour cherry cultivars. As far as individual cultivars are concerned differences in the nectar production and the sugar concentration are revealed rather between groups of cultivars than between individual cultivars. The pollen production of flowers was extremely changeable in consecutive years. Most honeybees collected nectar at sour cherry flowers; pure pollen gatherers and mixed behaviour bees were half as frequent but differences among the behaviour of honeybees according to cultivars cannot be stated. The fidelity of honeybees to sour cherry is less expressed than to some other fruit tree species. Accordingly, it is very strongly suggested to take the competitive effect other plant species (weeds) flowering in and around the orchard carefully into account when organizing additional bee pollination in sour cherry plantations. Several sour cherry cultivars possess more or less self-fertilization capacity but this is greatly changeable according to the season. It has been proved that self-sterile sour cherry cultivars are sensitive even on the partial restriction of the effective time of bee pollination and it is to be stressed too that even in the case of partly self-fruitful cultivars bee pollination is also vital in yield formation because medium or strong restriction of the effective bee pollination period is of a definite negative effect on their fruit set and yield. In years with unfavourable weather the yield can dramatically be reduced sometimes down to nil. However, very high fruit set is also unfavourable because a negative correlation was detected between the final set and the mean mass of fruits.

  • The effect of the limitation of insect pollination period on the fruit set and yield of temperate-zone fruit tree species
    90-95.
    Views:
    140

    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.

  • Relations of phenometrical indices of apple fruits with weather variation in the assortment of varieties of an apple gene bank
    115-120.
    Views:
    191

    The purpose of phenometry is to examine the measurable parameters of the plants in order to follow up the consequences of weather processes. We should fi nd the reasons, why the diameter of fruits grows larger in one season and smaller in the next. Variation may occur as a response to insuffi cient provision of water or nutrients, but also because of pathological effects and of extremely high or low temperatures, moreover, of extraordinary heavy fruit load. There are phenometrical characteristics, which consider the fi nal consequences (density of fl owers, fruits set, drop of fruits), whereas other parameters could be followed up (size, length and width of fruits) as the dynamic components of growth. The quantitative parameters of growth are functionally related to each other, where the weather conditions, soil humidity and nutrients are on the input side, thus it is possible to model the growth of fruits as a function of the environment. Initially, the relations between the main weather variables and the phenometrical data have to be cleared. In the present study, the interactions between the mentioned phenomena are presented and numerically defi ned.

  • Effect of postharvest sodium benzoate treatment on some fruit parameters of two organic apple cultivars
    35-37.
    Views:
    383

    The aim of this study was to investigate the effect of postharvest sodium-benzoate treatment on some fruit parameters of two organic apple cultivars (’Topaz’ and ’Florina’). Assessments were made at three times during storage: 17 November 2019, 20 December 2019 and 23 January, 2020. During every assessment dates, each fruit was observed separately, and determined the proportion of i) healthy fruits (%), ii) post-harvest fruit rot diseases iii) fruits with mechanical injury (%), iv) fruit with russetting (%), v) damage of codling moth and vi) Ca-deficiency symptoms. In addition, fruit weight (g) was measured at each assessment date. Sodium benzoate reduced the fruit decay and the proportion of healthy fruit was higher in this treatment compared to water treated fruit. This effect could be seen in all assessment dates and on both cultivars. Effects on other parameters were various according to cultivar and assessment dates. Loss of fruit weight was similar in both treatments and cultivars compared to control treatment.

  • Floral biology of plum (Review article)
    11-27.
    Views:
    150

    Floral biology of plum (Review article)

  • Some physical properties of apricots and testing apricot sorting machines
    51-62.
    Views:
    216

    Examinations were carried out in the manipulating and packaging plant of Gyümölcsért Ltd, in Boldogkôváralja, to determine some physical properties of five apricot cultivars and to test the work quality of the apricot sorting machines. The size and the weight of the fruits were measured and two sorting machines were tested. The results are given in tables and diagrams. The conclusions are also summarised.

  • Cooling irrigation as a powerful method for microclimate modification in apple plantation
    33-37.
    Views:
    243

    Irrigation in some countries is a horticultural practice mainly used only to supply water. At the same time the use of microsprinklers have a powerful influence on the changes of temperature in orchards. When the air’s temperature is high (about 20 °C or higher) the evaporative cooling irrigation significantly decreases the plants’ surface temperature and air temperature. The cooling effect is stronger when the air is dryer. By using cooling irrigation regularly, canopy temperature can be decreased so that the beginning of blooming can be delayed. Also if the blooming is early and frost probability is high, serious damages can happen in orchards. The beneficial effect of cooling irrigation is the temperature reduction and frost protection. InMarch 2010, one month earlier than the expected blooming an irrigation system was established to produce anti-frost treatment and regulate the micro-climate of a Gala apple orchard which belongs to the University of Debrecen (Hungary). The objective of sprinklers was to cool the air by increasing water evaporation and relative humidity. The position of the micro-sprinklers was planned in three levels (around the tree trunks, a few cm near to the soil surface, in the crown region and above the crown, a half meter higher). The results showed that the water sprayed in the orchard by micro-jets influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect. When water was applied at intervals of 15 minutes for ten times a day from 8 am to 18 pm, the air, flowers and bud’s surface temperature could be kept low.At certain days when the temperature was higher than 10 °C, irrigation was used at night time in similar 15 minutes intervals, from 18 pm and 6 am. The beginning of bloom could be delayed for more than ten days. The Gala apple variety blooming dynamics was characterized by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control one in spite of the equal temperatures measured in the plots. Under Hungarian climatic conditions, the method was successfully used to delay blooming dates. The main result was the diminution of the frost damage in the spring that assured apple yields.

  • Ecological drought resistance and adaptability of apple varieties
    113-122.
    Views:
    288

    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.

  • New sour cherry cultivars selected from local sources
    79-80.
    Views:
    268

    New sour cherry cultivars selected from local sources