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  • Post-storage sensory quality of apple varieties
    54-57.
    Views:
    123

    The changing situation of apple production in Hungary has given rise to a great demand for new varieties. Besides bearing capacity, fruit quality and suitability for new training systems, consumer preference is one of the grower's main considerations. Growers need reliable information in order to choose the appropriate variety, so consumer tests have become essential. Altogether, 1 I traditional and new varieties were involved in this project. In the first part of the experiment, panelists ranked the coded samples according to their appearance. In the second part, apples were cut into unpeeled slices and the samples were also coded. The assessors were asked to taste them and rank them again. The sensory tests were held after three different storage periods.

  • Role of organosilicone surfactant in apple scab control under scab conducive weather conditions
    23-25.
    Views:
    195

    Fungicides of integrated fruit production (dithianon, captan, and diclofluanid) and an organosilicone surfactant were compared in spray schedules from green tip until summer in order to control apple scab caused by Venturia inaequalis and to evaluate their phytotoxicity on fruit. Sixteen sprays of 1.8 kg ha-1captan, 0.41 ha-1 dithianon, and 1.8 kg ha-1 diclolfluanid significantly (P=0.05) reduced the incidence of leaf or fruit scab compared to unsprayed products. All fungicides applied with organosilicone at 0.1% resulted in lower incidence of scab on young and older leaves as well as on harvested fruit, but these were not statistically always better than fungicides applied alone. In case of diclofluanid, the fungicide applied with organosilicone at 0.1% resulted in significantly lower (P = 0.001) incidence of scab on young and older leaves. Diclofluanid applied with organosilicone at 0.1% gave the best scab control on leaf and fruit. Treatments applied with fungicides alone had no significant effect on plant phytotoxicity compared to untreated control. All fungicides applied with organosilicone at 0.1% increased (P = 0.05) fruit damage compared to untreated control or fungicide applied alone, though these were not always significantly different. In case of percentage of fruit russet, treatment of dithianon 0.4 1/ha + 0.1% organosilicone significantly increased fruit russet, while fruit russet index significantly increased in the treatment of diclofluanid 1.8 kg/ha + 0.1% organosilicone compared to untreated control. In sum, application of surfactants can help to increase efficacy of scab fungicides; and consequently, to reduce the risk of fungus infection under high scab disease pressure. This fact may also be helpful in fungicide resistance management and reduced-spray programs with accurate scab warning systems.

  • Effects of different cytokinins on the shoot regeneration from apple leaves of 'Royal Gala' and 'M.26'
    69-75.
    Views:
    213

    The effects of different types of cytokinins on the shoot regeneration from leaf explants of apple scion 'Royal Gala' and apple rootstock 'M.26' were evaluated. Regeneration media contained either thidiazuron, or 6-benzylaminopurine, or meta-topolin, or zeatin, or kinetin, or their N9-ribosides, respectively, in the concentration range 0.5 to 8.0 mg 1-1. Effects of 'these cytokinins were evaluated on the percentage of regeneration (R%) and that of vitrification (V%) and on the number of regenerated shoots per explant (SN). Organogenetic index (0I) calculated from these data was used for the evaluation of efficacy of cytokinins. The course of shoot organogenesis also was followed using stereomicroscope. Types and concentrations of cytokinins applied in the regeneration media influenced each parameter significantly and the regeneration answer was strongly genotype-dependent. The best regeneration (SN: 11.08, 01: 7.5) was achieved in `Royal Gala' by using TDZ in concentration of 0.5 mg 1-1 (2.271,1M). There was a clear relationship between the effect on the regeneration efficacy and the chemical structure of cytokinins considering classical cytokinins, namely N9-ribosides applied in less concentration than non­ribosides have the same or best regeneration effects except for 6-benzylaminopurine riboside. However, similar relationship could not be detected in the case of 'M.26'. SN was the highest (3.22) using 6.5 mg 1-1 (18.2011M) 6-benzylaminopurine riboside or 8.0 mg 1-1 (21.44 µM) meta-topolin riboside (3.18). SN was not significantly lower (3.12) by using 2.0 mg 1-1 (9.08 1M) TDZ, however, OI was about half as big (0.63 compared to 1.29 or 1.74 with 6-benzylaminopurine riboside or meta-topolin riboside, respectively). 'Royal Gala' had higher organogenetic ability, than `M.26': 3.5-fold higher shoot number per explant and more than 4-fold higher organogenetic index was reached with this cultivar than with 'M.26'. Moreover, the similar developmental stage of shoots could be observed 3-5 days earlier than in 'M.26' and if explants of 'Royal Gala' were further cultured with 3 weeks, SN increased from 11.08 to 24.42 on TDZ-containing regeneration medium, which might suggest higher organogenetic ability, too.

  • Molecular identification of old Hungarian apple varieties
    37-42.
    Views:
    254

    Altogether 40, mainly old Hungarian apple varieties were screened with six previously described microsatellite markers. A total of 71 polymorphic alleles were detected (average 11.8 alleles/locus) and the heterozygosity of markers averaged very high (0.8). The genetic variability among the genotypes proved to be so remarkable that as few as three markers from the applied six were enough to distinguish between the 40 varieties. This was also confirmed by the cumulative probability of obtaining identical allele patterns for two randomly chosen apple genotypes for all loci, which value was quite low: 2.53 x 10-5. The molecular identification of these genetically very different old apple genotypes could be very useful in future breeding programs.

  • Volumetric estimation of an intensive apple orchard with GIS
    7-10
    Views:
    328

    Remote sensing instruments and methods have become widespread in all segments of agriculture and horticulture. Among the innovative development of remote sensing instruments, the 3D laser scanner is one of the newest technique, which overtop in the spatial data collection. Terrestrial laser scanning is an appropriate tool for identifying such biophysical parameters like the structure of trees and branches, growth of volume. Determination of these parameters are time consuming and complicated with traditional methods. The examination was carried out in the Study and Regional Research Farm of the University of Debrecen near Pallag. We used Leica ScanStation C10 terrestrial laser scanner to estimate volumetric properties of the intensive apple orchard. Two rows of the study area were surveyed, where the height and stem diameter of apple trees were measured with Geomagic Studio 12 GIS Demo Software. Based on the built-in algorithms, the volume of each tree were defined by the software. The measured and calculated data was correlated, and middle correlations were detected. Estimated volume results could be useful for further investigation such as CO2 fi xing, which is an important factor for ecological service of the plantation.

  • Growth and productivity of a young apple orchard at different spacing
    23-27.
    Views:
    154

    Planting of new high density apple orchards showed an increasing tendency over the last ten years. Growers use in those orchards mainly dwarfing or semi dwarfing rootstocks. The spacing for those orchards is recommended based on Dutch and German experiences; however, the optimization of orchard planting density as a key factor for successful orchard management should consider the local climate conditions. An experimental orchard was planted in 2000 to investigate the effect of spacing on three dwarfing rootstocks with two apple cultivars `Jonica' and 'Gala Must'. We compared 8 planting densities (1270-3704 tree/ha) and two tree shapes (slender spindle and vertical axis). In this paper the data of the first five years' growth and bearing are presented. After 4 years, the decreasing tree densities caused reduced trunk cross sectional area. Tree density had a significant positive effect on cumulative yield per hectare. From the examined rootstocks, M.9 Burgmer 984 gave the smallest canopy for both cultivars. The trees on M.9 T.337 and on Jork 9 rootstocks have stronger growth. The light interception was measured under the canopy by AccuPAR (Decagon Devices Inc.'s).

  • Freeze Susceptibility of Fruit Buds in 67 Apple cultivars in Hungary
    29-35.
    Views:
    131

    Frost damage is one of the most important risks of apple production. Outstanding importance has been attributed to the frost resistance of flower-buds as decisive sites of fruit production. Browning of plants parts and tissues exposed to natural weather adversities are considered as effects of frost. In Hungary, frost damage on flower buds of both the market and new cultivars has not been assessed earlier. Observations referring to the consequences of frost damages of over four critical years, marked by their peculiar winter and spring frost hazards. Parallel observations have been made in four sites of the growing area in the Great-Plain region. 67 apple cultivars have been assessed. Each cultivar was represented by 3 trees, which were sampled at about 1-1.5 m height over ground, where the buds or inflorescences were picked for the purpose to assess the injury. The buds and flowers are cut longitudinally and rated visually according to the extent of browning of the organs and tissues. Susceptibility of different organs of the flower (pistils and anthers) were rated separately. According to our results, most resistant to spring frosts are the following cultivars: 'Gloster', 'Granny Smith' and appreciable tolerance is attributed in 'Gala' and 'Jonathan' with derivatives. Preliminary results that among the scab resistant cultivars, `Baujade', 'Rewena', 'Liberty', `Resi' and 'Renora' are rather frost resistant. Information, lacking hitherto, is obtained upon 'Reka' and 'Reglindis' as for their increased susceptibility.

  • Genetic diversity in a collection of apple (Malus x domestica Borkh.) cultivars as revealed by RAPD markers
    25-35.
    Views:
    179

    A collection of 151 apple cultivars was investigated with 7 RAPD primers generating 71 informative bands, to evaluate genetic variability and relatedness. All cultivars presumably derived through genetic recombination were distinguished whereas identical DNA profiles indicated that some cultivars had arisen as sports. A cluster analysis and a PCO did not reveal any distinct geographic patterns, but there was a weak tendency for Swedish and foreign cultivars to differentiate.. Many cultivars however clustered together with either one of their parents or with siblings. Overall genetic diversity among the 151 cultivars was estimated with Nei's diversity index (H), 0.269, and with Shannon's index (H'), 0.594. The cultivars were also analysed in six groups, according to time of origination and country of origin, with an average H = 0.262 and H' = 0.546. No major differences in genetic diversity were observed over time or space, although the group with recent, foreign cultivars had the lowest diversity (FL = 0.235, H' = 0.493). Comparison between the entire material and a subset with 94 mandate cultivars chosen for preservation in Sweden, showed similar genetic diversity: HFN.rj1E = 0.268, frE,NTIRE, = 0.593 and HMANDATE = 0.263, WMANDATE = 0.575. No major differences in band frequencies were observed between these two sets, but 5 RAPD bands were missing in the set with mandate cultivars.

  • Identification of the apple firmness: two case studies
    32-35.
    Views:
    112

    Firmness tests were performed with peeled and entire fruits of Elstar and Jonagold apple cultivars for identification and comparison. The normal distribution of the tested population was acceptable (level: 95%). The green and the red sides did not show differences within the cultivar but they were different in firmness. There was not significant difference between the flesh tissue firmness values, however the firmness of the entire (not peeled) fruits was different. This result was caused by the effect of the peel. The variability of the firmness with Jonagold was caused by the peel, but such a result was not found with Elstar. The test of the peel effect would be interesting with different cultivars and a sequence according to the firmness can be estimated.

     

  • Preliminary study on micro area based spatial distribution of powdery mildew in an organic apple orchard
    35-37.
    Views:
    204

    In this study, the objective was to report a preliminary study on micro area based spatial distribution of powdery mildew in an organic apple orchard. Results showed that number of symptomatic plant part ranged between 11 and 20 on shoot and between 9 and 24 on fruit. Number of asymptomatic plant part ranged between 85 and 109 on shoot and between 133 and 206 on fruit. Disease incidence ranged between 13.8 and 17.6% on shoot and between 9.1 and 11.3% on fruit. Disease aggregation index ranged between 0.098 and 0.228 on shoot and between 0.043 and 0.108 on fruit. One of the four trees showed significant within canopy aggregation of disease for shoot powdery mildew symptoms in both years. For leaf powdery mildew, all tree exhibited random patterns in both years.

  • The effect of the intensity and method of pruning on the growth and yield of the apple variety ’Idared’ under conditions of ecological and integrated growing systems
    35-39.
    Views:
    357

    Summary: On the Experimental Farm of the Debrecen University at Pallag, a factorial experiment has been started at springtime of 2008 on an orchard of 12 year old apple trees ’Idared’ grafts on M 26 understocks. The first factor was the growing system (integrated versus ecological), the second was the intensity of pruning (strong versus moderate thinning of the crown), whereas the third was the method of pruning (shortening versus thinning of individual shoots). Measurements have been concentrated on shoot growth, flower initiation, fruit set and accumulated yield of two successive seasons. The following conclusions are made.
    – In the ecological growing system, strong thinning proved to be beneficial for growth as well as for fruit bearing. – Strong thinning combined with shortening of shoots diminished yield in the first year, whereas
    moderate thinning combined with shortening of shoots caused favourable growth and fruit bearing.
    – In the ecological growing system, the moderate shoot growth was associated with better flower initiation, which increases the chances of alternate yielding.
    – According to our results, the flower initiation of the ‘Idared’ was stimulated univocally by the thinning of shoots regardless of the intensity of pruning.
    The right choice of the intensity and method of pruning is a decisive moment of a successful yield in the ecological apple growing system

  • Prediction infection risk on the basis of weather-related factors and Erwinia amylovora colonization in apple and pear flowers
    39-54.
    Views:
    161

    Current infection risk prediction models utilize environmental parameters and field records, but do not take into account the estimated inoculum potential within the orchard. The object of this study was to survey the accuracy of three simple prediction methods under Hungarian climatic conditions, which could easily be used by the farmers. We also tested whether the accuracy of infection risk predictions can be improved by taking into consideration the incidence and/or rate of flower colonization by Erwinia amylovora.

    After preliminary investigations in 1999-2001, data concerning the weather-related infection risk were recorded in 5 apple and 1 pear orchards in 2002, and in 12 apple and I pear orchards in 2003. The weather data were processed by the easy-to-use risk assessment models of the mean temperature prediction line (MTL), Smith's Cougarblight 98C and Billing's integrated system (BIS), and by the MaryblytTM 4.3 computer-assisted model for reference. The population size of E. amylovora in the flower samples was estimated within an order of magnitude by PCR.

    For all years and orchards tested, Maryblyt indicated 35 days on which there was an acute infection risk. The same days were indicated by all 3 methods in 23 cases (66%), 8 days were indicated by 2 methods (23%) and 4 days were indicated by 1 method only. A similarly good correlation was found for prediction of the date of the first massive infection risk: in 2003, for instance, there was a perfectly consistent prediction by all 4 models in 9 of the 13 participating orchards. A coincidental forecast was provided by 3 of the 4 models in the other 4 orchards.

    The results indicate that any of the risk assessment models could provide an increased accuracy of the actual infection risk prediction if combined with an estimation of the incidence of Erwinia amylovora colonization in the open flowers. We found no convincing differences in the size of the epiphytic population in flowers of cultivars possessing high or low susceptibility to Erwinia amylovora.

    We conclude that the easy-to-use methods tested could be used by the fanners to recognize weather-related risks, especially when coupled with an estimation of the proportion of the pathogen-infested flowers. This local prediction would provide rapid information (faster than the regional forecast systems) specifically for a given orchard.

  • Flower production of apple varieties grown by different environmental technologies
    47-49.
    Views:
    163

    The flower production of four apple varieties have been observed grown in integrated and in ecological growing technologies during the spring of 2010. The trees produced in the last year (2009) nearly similar yields, so the effect of the technologies may causen differences in the production of flowers. According to our results, the ecological technology produced higher flower densities in the majority of variables, which was in relation with the vigor, branching and thickening of the trunks. The varieties observed displayed substantial differences in the appearance of fruiting structures of different age on the branches. This information may prove to be essential for the decisions to be made in timing and severity at the pruning operations.

  • Spore dispersal, diurnal pattern and viability of Monilinia spp. conidia and the relationship with weather components in an organic apple orchard
    17-19.
    Views:
    247

    In a two-year Hungarian study, spore dispersal diurnal periodicity and viability of Monilinia spp. and their relation to weather components were determined in an organic apple orchard. Conidia of Monilinia spp. were first trapped in late May in both years. Low number of conidia were trapped until end-June. Thereafter, number of conidia continuously increased until harvest. Conidia in a 24-h period showed diurnal periodicity pattern, with th highest concentration in the afternoon hours. Spore viability with FDA staining showed that viability of
    conidia ranged from 45 to 70% with showing lower viability in the dry than in the wet days in both years. Temperature and relative humidity correlated positively with mean hourly conidia numbers in both years. Mean hourly rainfall was negatively but poorly correlated with conidiacatches in both years. Results were compared and discussed with previous observations.

  • Integration of terrestrial laser scanning and spectral canopy scanner in horticulture applications
    15-18.
    Views:
    264

    One of the most difficult challenge in the everyday practice to describe the canopy growing of fruit trees in an orchard. The photosynthetic activity is the basic of the primer production of plants. The measurement of leaf area and determination of the photosynthetic activity could be occurred with some elaborated methods between experimental conditions. In this article we present such an integrated methodology, which is ideal to determine the geometric and spectral characteristic of fruit trees between field conditions.We have carried out laser scanning technology to investigate the geometric-topological characteristics and parallel the active infra-red sensor to collect spectral data about an apple orchard. The surveys were worked out in an intensive apple orchard with drip irrigation system, protected by hail net in Study and Regional Research Farm of the University of Debrecen near Pallag. This study shows the filtering and interpretation methods of created data. The produced high accuracy data can be directly used in the precision horticulture. It could serve as a guiding data to implementation a future “virtual horticulture”. Higher spatial and temporal resolution could help for a better recognition of water balance of orchards.

  • Test of the utility of apple retrotransposon insertion patterns for molecular identification of 'Jonathan' somatic mutants
    7-10.
    Views:
    196

    Up until today, apple sport mutants proved to be indistinguishable from each other and their progenitors at the molecular level using random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) marker techniques. This is not surprising, since the genomes of these somatic mutants differ only in one or a few small regions that affect economically important characteristics, such as improved fruit colour, size, or flavour. In most cases, these genome differences are probably caused by retrotransposons which are able to convert their RNA transcripts to DNA with reverse transcriptase enzyme prior to reinsertion, but unable to leave the genome and infect other cells. Retrotransposon insertions can alter the expression of other genes and/or the structure of encoded proteins. The sequence-specific amplified polymorphism (S-SAP) technique is capable of revealing the genetic distribution of retrotransposable elements over the whole genome. The present study used this approach to try to characterize and distinguish 'Jonathan' somatic mutants via fingerprinting, which is an unsolved problem.

  • Dynamics of the uptake of nutrient elements from the medium of in vitro cultured apple rootstocks
    50-53.
    Views:
    154

    Cation uptake of J-TE-F apple rootstocks propagated in vitro was studied by the analysis of culture medium. Test-plants were grown on liquid medium under different light regimes. Samples for tests were taken twice a week.

    Media without plants served as controls. The analysis of those showed, that only the uptakeable iron-content changed depending upon light treatment. The concentration of all other cations was considered unaltered.

    As a result of analysis, it could be established, that elements present in the media were taken up in different rates by plantlets: Cu, P and Zn were utilized totally, but only 50% of K and 20 to 40% of Ca and Mg were taken up under the light treatments applied.

    The dynamics of the uptake process was also observed. It was registered that they differed in the case of some cations. So Ba was utilized at the beginning of subculture, others for example B in the later phases. Some elements disappeared unevenly so K, P but the whole quantity is taken up during subculture.

  • Preliminary study on micro area based spatial distribution of Monilinia fructigena in an organic apple orchard
    19-21.
    Views:
    208

    In this study, we aimed to report a preliminary study on micro area based spatial distribution of Monilinia fructigena in an organic apple orchard. Results showed that number of symptomatic fruit ranged between 22 and 42 in 2013 and between 25 and 35 in 2014. Number of asymptomatic fruit ranged between 111 and 187 in 2013 and between 119 and 167 in 2014. Disease incidence of fruit ranged between 19.7 and 23.2% in 2013 and between 19.1 and 26.5% in 2014. Disease aggregation index ranged between 0.111 and 0.335 in 2013 and between 123 and 401 in 2014. Three of the four trees showed significant within canopy aggregation of disease for fruit brown rot symptoms in both years. However, the remaining one tree exhibited random patterns during both years. Disease aggregation indicated a disease spread by fruit-to-fruit contact and/or an aggregated
    pattern of insect damage.

  • Effects of integrated and ecological growing technologies on the growth and development of fruiting structures in new apple plantations
    31-33.
    Views:
    174

    On the Horticultural Station of the Debrecen University, Pallag, two year old apple plantations of two varieties (‘Pinova’, ‘Golden Reinders’) have been studied, in autumn 2011. The growth of the cross section area of the trunk and the central axis were measured and compared to evaluate the effect of two alternative growing technologies: integrated and/or ecological. ‘Pinova’ proved to grow more intensely than ‘Golden Reinders’ independently from the growing technology. The effect of the technology, however, was expressed in ‘Pinova’, where the integrated technology produced more vigorous growth than the ecological one. The effect of varieties on growing intensity was more distinct than the effect of growing technologies. Under the ecological growing system, the difference between the varieties studied is more accentuated regarding growing intensity. By that reason, in ecological growing plantations of varieties with moderate vigour ought to be stimulated by all possible techniques (as pruning, nutrition etc.).

  • Vegetative and generative properties of two apple cultivars ‘Galiwa’ and ‘Story Inored’ in a multi-row system
    34-38.
    Views:
    240

    In a five-year (2015-2019) study, some vegetative and generative peculiarities of two resistant apple cultivars (‘Galiwa’ and ‘Story Inored’) were assessed in a young orchard with a multi-row training system. Based on our research, cv. ‘Galiwa’ showed significantly weaker growth, than cv. ‘Story Inored’, which was manifested in lower trunk cross sectional area (TCSA) and lower tree height. Cultivar ‘Story Inored’ reached the optimal tree height (3.1 m) at the age of four, but cv. ‘Galiwa’ could not achieve it neither in five-year-old trees (2.7 m). Cultivar ‘Galiwa’ showed 28.4-32.6 t/ha calculated average yield, while cv. ‘Story Inored’ produced 41.3-102.7 t/ha. Larger fruit size was found in cv. ‘Galiwa’ (72.7-79.1 mm) and smaller in cv. ‘Story Inored’ (66.9-69.2 mm). The fruit surface color was under 50% for cv. ‘Galiwa’ (43-49%), meanwhile cv. ‘Story Inored’ reached higher coloration (87-93%) and an excellent color intensity (4.8-5.0). Shape of cv. ‘Galiwa’ fruits was rather flat, than globular (0.83-0.84 shape index), as cv. ‘Story Inored’ was more elongated (0.95-1.00 shape index).

  • Growing characteristics of apple cultivars in environmentally friendly growing systems
    7-10.
    Views:
    244

    Nowadays the condition of the good saleability of the fruit is the application of controlled environmentally friendly technologies. Success of the growing is basically influenced by the production value of the cultivars, and their flexibility to the different technologies. In our examinations the effect of the integrated and organic farming  system has been evaluated on the growing characteristics of the apple cultivars. According to our results the trunk thickness of the trees both in the initial and both in the later bearing period is higher in the integratedproduction compared to the organic farming system. This differences most likely caused by the variance of the crop load.

  • Spatial evaluation of the apple trees-soil environment
    53-56.
    Views:
    200

    Remote sensing of fruit tree micro environment plays a major role in both horticultural and soil mapping applications. In frame this study presented a novel method to survey the spatial distribution of physical and water management properties of soils. The examinations were carried out at an intensive experimental apple orchard in Debrecen-Pallag. The examination site is the part of the Experimental Pomology plantation of the University of Debrecen, Faculty of Agronomy. Particle-size distribution, plasticity according to Arany, metal content by XRF spectrometry, soil physical parameters, acidity, electric conductivity of soils, were measured to obtain appropriate information on the physical properties of the soil. Based on the results, the accurate spatial positions of those sites were characterized where soil loosening should be implemented in 0,3–0,4 m depth. Spatially precise soil physical barriers were determined for applied micro-irrigation system. Based on the micro-element content and pH, the accurate spatial positions of those sites were selected where melioration and micronutrient fertilization is needed. These detailed data sources also applied to calibrate the applied airborne hyperspectral images to extend spatially these point based information.

  • Flower visiting activity of honeybees on fruit species blooming subsequently
    12-16.
    Views:
    174

    In the small demonstration orchard of the College Faculty of Horticulture at Kecskemét the blooming time, the flower density and the honeybee activity was observed at a number of cultivars of 20 flower species during four consecutive years.

    Fruit crop species were in flower during 3-4 months altogether. The blooming period of them was classified into five groups as early (almond, apricot, gooseberry), middle early (sweet cherry, red currant, currant-gooseberry, black currant, white currant, peach, plum, sour cherry), middle late (pear, strawberry, apple), late (black elder, quince, medlar, raspberry, blackberry-raspberry) and very late blooming period (blackberry). The blooming period of the members of the groups of early and medium early blooming often coincided partly and the same happened between the medium and the medium late as well as between fruits of late and very late flowering.

    The flower density of some fruit species is extremely variable (currant-gooseberry, medlar), while at others it is fairly stable and evenly dense in consecutive years (sour cherry, sweet cherry, strawberry). At other fruit species it is moderately changeable. Some fruit species tended to attract more honeybees than others (plum, apple, quince, medlar) and some of them tended to attract much less (black elder, pear) but most species can be regarded as of medium attractivity.

    On the flowers of some fruit species (pear, strawberry, quince) honeybees gathered pollen predominantly. At most fruit species however pollen and nectar gathering behaviour seemed to be gradually changing during the season. Namely most honeybees tended to gather pollen at the flowers of the early blooming fruit species, but on the other hand typical foraging behaviour gradually shifted to nectar gathering at the flowers of fruit species of moderate and late blooming periods.

     

  • Effect of the environmentally friendly production systems on the vegetative characteristics of apple cultivars
    11-14.
    Views:
    328

    In this study effect of the environmentally friendly production systems on the brunch cross sectional area of apple trees trained to free spindle canopy are presented based on the data of 39 cultivars. According to our results branch thickness of the apple cultivars located in the lower, middle and upper region of the tree are more homogenous in the integrated production system compared to the organic one. Therefore the severity of the annual maintain pruning must be necessarily more moderate in the integrated growing system, than in the organic production system.

  • Some structural characteristics of the flowers of apple cultivars with different susceptibilty to fire blight
    21-23.
    Views:
    121

    Several morphological characters of the hypanthium (size and form of the surface, the shape of the hypanthium) and anatomical traits (number and pattern of stomata) of apple cultivars (Malus domestica L.) with different susceptibility to fire blight were studied. The size of hypantium surface was calculated by modelling the hypanthium with a truncated cone. Three types of hypanthium surface form have been revealed: straight, convex and a complex "shouldered" one. The angle between the style and the wall of the hypanthium was narrow or wide. The stomata on the hypanthium surface can be arranged in a zone in the middle third of the hypanthium or dispersed more or less evenly. The number of stomata/flower substantially differed among the cultivars examined. The highest stomata number was detected in the flowers of the tolerant cultivar (Freedom)

    No single characteristics of the hypanthium could convincingly be correlated with susceptibility to fire blight. We suggest, however, that combination of morphological properties that sustain moist environment in the hypanthium contribute to susceptibility.