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  • Growing characteristics of apple cultivars in environmentally friendly growing systems
    7-10.
    Views:
    255

    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.

  • Histological studies on some native perennials
    79-82.
    Views:
    150

    Growing of native perennial species became more and more popular in the last ten years. In order to obtain more information on their histological structure, investigations were done on Aster linosyris, Inula ensifolia and Prunella grandiflora. The histological features are usually relating to the plants' ecological demands which is an important aspect in their growing. Differences were found in the structure of the stem of Asteraceae and Lamiaceae members. While separated vessels were formed in the stem of Aster linosyris and Inula ensifolia, continuous vessel-system forms in the stem of Prunella. Alternating segments of collenchyma and chlorenchyma are found in the stem of Aster linosyris, while palisade parenchyma is situated both on the abaxial and adaxial surface of the leaves. Vessel-system of the root is tetrarch. Histological structure of the stem of Inula ensifolia differs from Aster linosyris in the broader cortical parenchyma which is composed of approx. 8-12 cell layers. It contains neither collenchyma nor chlorenchyma. In the stem of Prunella grandiflora a nearly continuous vessel-ring is formed from the four primary vessels. Long, multi-celled hairs were observed in the district of angles of the stem.

  • Evaluation of essential oils by gas-chromatography and a new method: "electronic nose"
    85-89.
    Views:
    175

    The chemical quality of the essential oils is determined by their composition as well as by the complex aroma features. For the evaluation of odour and aroma, sensory tests are practised, especially for applications such as aromatherapy, food industry or perfumery. In the recent studies we investigated eight Mentha origins (populations of Mentha iperita, M. spicata and M. arvensis) of our genebank collection using a new and effective instrumental sensory evaluation method parallelly with the usual GC analysis.

    The results show that the examined mint clones possess different essential oil accumulation levels and special flavour characteristics, too. The GC analysis of the essential oil revealed characteristic differences at both inter- and intraspecific level in the proportion of mentol, menthon, carvon, limonene, menthyl acetate and in two not identified monoterpenes.

    In the sensory tests the special complex aroma enables a reliable distinction with a single exception among the populations by the help of the "electronic nose" equipment. The distinction among the samples based on the sensor signals of the instrument — evaluated by multivariate methods — shows a close relation with the detected monoterpene components of the essential oil.

     

  • Cherry leaf spot incidence on 12 sweet cherry cultivars in integrated production
    65-67.
    Views:
    244

    The aim of this study was to evaluate the cherry leaf spot (CLS) incidence on 12 sweet cherry cultivars in integrated sweet cherry production in three consecutive years from 2010 till 2012. Assessed cultivars (cvs.) were ’Aida’, ’Axel’, ’Biggareau burlat’, ’Blaze Star’, ’Celeste’, ’Germersdorfi 3’, ’Izabella’, ’Katalin’, ’Krupnoplodnaja’, ’Linda’, ’Sunburst’, ’Vera’Results showed that year had an essential effect on the CLS disease incidence. Cultivars showed great differences within years. Cultivar ’Celeste’ showed the lowest disease incidence on leaves in all years lower than 10%. The largest disease incidence on leaves was on cv. ’Sunburst’ in 2010, on cv. ’Germersdorfi 3’in 2011 and on cv. ’Axel’ in 2012. Disease incidence on these cultivars ranged between 10 and 25%.

  • Hail data analyses
    99-103.
    Views:
    130

    Long term data of hail events of three meteorological stations (Budapest, Debrecen and Szeged) were investigated. The hail event frequencies show significant differences in the time period 1901–2000 when the first and the second half of the century are compared. The frequencies of hail events are higher in the first half of the century in case of Debrecen and Szeged while it is higher in the second 50 years for Budapest. None of the frequencies of hail events in between 2001–2008 are significantly higher, though the average of precipitation fell during these events is higher except for Szeged. We have found that the results about the monthly distribution of hail events differ from the ones in the literature; the ratio of hail events is significantly less in the vegetation period.

  • Fruit drop: II. Biological background of flower and fruit drop
    103-108.
    Views:
    378

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

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

  • Grapevine and apple replant disease in Hungary
    57-61.
    Views:
    154

    Field experiment was conducted to study the replant problems of grapevine and apple. Plantings were in three different fields: on virgin soil, on apple replant soil and on vine replant soil. Each field was planted with 60 pieces of grafted vine (variety Bianca on rootstock Berl. X Rip. T.K. 5BB) and 60 pieces of grafted apple (variety Gloster on rootstock MM. 106). Fungicide (BUVICID K with 50 % captan agent, 0.5 g/1 1 soil) and nematocide (VYDATE 10 G with 10 % oxamil agent, 0.03 g/1 I soil) treatments were used in the soil in order to identify the causal factor of the problem.

    Biological soil test was conducted to test 17 soil samples of II wine districts and vine growing fields in plastic pots, under shading net. No root pieces were left in the soil. Two bud-cuttings of the Bed. X Rip. T 5C rootstock varieties were used as test plants. In each case, samples were taken from the vineyard and from the virgin soil. One fourth of the soil from the vineyard was left untreated and the other three part was treated with nematocide, fungicide or heat.

    The results of the field experiment suggest that there was no problem growing grapevine after apple and apple after grapevine, but both species had been inhibited growing after itself. The fungicide and nematocide treatments did not succeed in determining the casual factor of the problem. Heat treatment of replant soil (in pot test) was useful in AS and VNS soils.

    Results of biological soil test suggest, that grapevine replant problem do not occur in every vineyard. In fifty percent of soils, no significant differences between the treatments for shoot length, weight of cane, length, diameter and wood:ratio of the fourth internode were observed. In one case, difference was not found in any of the measured characters. However, fruiting bodies of Roesleria pallida (Pers.)Sacc. and the mycelium of Rosellinia necatrix Prill. were observed in this sample. In other samples, there was no significant difference between the treatments, but nematode and fungus infection appeared to be involved in increased shoot growth in nematocide and fungicide treated plants (mycelium of Rosellinia necatrix was detected). In other samples, the fungus infection caused significant difference between the virgin, untreated and fungicide treated soils and infection of Rosellinia necatrix was observed.

  • Association of varieties in stone fruit plantations
    29-33.
    Views:
    205

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

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

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

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

     

  • Structural differences arise between fruit cuticles of two apple cultivars during long term cold storage
    26-29
    Views:
    292

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

  • Incidence of postharvest decays on cultivars of pear, apricot, sour cherry and peach under two storage conditions
    63-65.
    Views:
    347

    In this two-year study, postharvest decays of pear, apricot, sour cherry and peach cultivars under two storage methods (TC and CA) were determined after four monthes storage periods; and then causal agents of postharvest decays of two pear cultvars were idenfified under traditional cold storage conditions. Results showed that postharvest decay was lower under controlled atmosphere compared to traditional cold one. Decay was lower on pear and the largest deacy occured on peach and apricot cultivars. Cultivars of fruit species also showed differences in incidence of fruit decays. Incidence of decays was independent on year effect. Under controlled atmosphere, postharvest decay ranged between 0 an 8% for pear, and between 5 and 12% for apricot, and between 6 and 11% for sour cherry, and between 5 and 15% for peach. Under traditional cold storage, postharvest decay ranged between 16 an 21% for pear, and between 15 and 39% for apricot, and between 10 and 22% for sour cherry, and between 19 and 33% for peach. Incidence of pear fruit damage ranged between 7.5 and 12.3%. Most damage started from injured fruit or wounded fruit. Five types of damage occurred ont he pear fruits in both years: Penicillium spp., Monilinia spp., Chondrostereum spp., other pathogens and mechanical injury. The most common damage was caused by Penicillium spp., Monilina spp. and Chondrostereum spp. On both pear cultivars in both years.

  • Test of the utility of apple retrotransposon insertion patterns for molecular identification of 'Jonathan' somatic mutants
    7-10.
    Views:
    233

    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.

  • Propagation of plum rootstocks by hardwood cuttings
    23-28.
    Views:
    137

    Vegetative propagation by hardwood cuttings is a very simple and cheap method for production of plum rootstocks. The aim of this study was to examine if this propagation technique is suitable for practice of three plum rootstocks and find the time or period when the percent of rooted cuttings is maximal. Based on our results, hardwood cuttings of the rootstocks tested have the rooting potential acceptable for practice, however, for Fehér besztercei in the previous literature leafy cuttings are recommended. Fehér besztercei reached 74.0% rooting, cuttings of Sainte Julien GF 655/2 rooted in as high percentage as 78.3%, and Marianna GF 8-1 had 88.3% rooted cuttings. Rooting potential of hardwood cuttings depends on more factors, one of them can be their dissimilar sensitivity for the diverse environmental circumstances at the different propagating dates, affecting through the internal biochemical changes that can be in relation with the differences in their dormancy.

    The cuttings of Marianna GF 8-1 take root easily, but in some years the conditions were less favourable for reaching maximal rooting. For taking cuttings the period from the beginning of October until December was optimal. For Fehér besztercei the optimal date of cutting collection was around the end of October, but in some years the rooting in the middle of December was also high. Sainte Julien GF 655/2 definitely rooted best in October. The treatments with different IBA concentrations in two years affected differently the rooting percentage. The rooting of Marianna GF 8-1 and Sainte Julien GF 655/2 is barely influenced by the different hormone dose in both years. Hardwood cuttings of Fehér besztercei rooted definitely better when treated with 2000 ppm IBA in comparison to untreated ones, while in 2001-2002 there was no difference between 2000 and 4000 ppm.

     


     

  • Effects of aromatic cytokinins on structural characteristics of leaves and their post- effects on subsequent shoot regeneration from in vitro apple leaves of 'Royal Gala'
    41-46.
    Views:
    185

    The effects of different aromatic cytokinins applied in different concentrations and combinations were investigated on the histology of in vitro apple leaves and their post-effects on subsequent shoot regeneration from these leaves were studied. Great differences in the anatomical structure of leaves could be detected originating from media containing different types and concentrations of aromatic cytokinins. The number of regenerated shoots per explant and the organogenetic index were used for the evaluation of the post-effect of aromatic cytokinins on shoot regeneration. The histological structure of leaves used for regeneration and their regeneration response showed a good correlation. When the pre-treatment caused a juvenile-like or less-differentiated structure, the number of regenerated shoots per explant increased and often vitrification also decreased and consequently the organogenetic index also increased. A strong interaction between cytokinin-content (type and concentration) of the pre-treatment medium and that of the regeneration medium could also be detected.

  • Application of pollen mixing device in front of the hive entrance
    151-152.
    Views:
    136

    The model of a pollen mixing device was tested in sunflower culture in order to detect the effectiveness in helping the out-going honey bees to carry more and different varieties of pollen grains on the body and body hairs. This model is build from line hairs of brushes facing each other that can keep and release pollen grains. The brushes are functioning as pollen receiver-transmitter units. The effectiveness was tested by examining the number and the species of the pollen grains adhered to the bees passing through the entrance. The amount of pollen and the number of pollen species on the hive with the device was significantly higher than on the control hive.

    The data were analysed by variance analysis and significant differences were found according to the number and species of pollen grains between the incoming and outgoing bees.

     

  • Relation of sour cherry blooming dynamics and meteorological variables
    17-23.
    Views:
    272

    The aim of our research was to identify the role of weather parameters in the development of the start date and length of blooming. In order to achieve this, we examined how meteorological conditions of a particular year influence the start date and length of blooming in different years (dry, wet, cool, hot, sunny, cloudy). The meteorological parameters were the following: maximum temperature, minimum temperature, average temperature, precipitation, length of sunlight, difference of daytime and nightime temperatures, potential evaporation-PET, Huglin-index,Winkler-index, climatic water balance which can be calculated as a difference of precipitation and potential evaporation. In this study we wanted to find out whether early start of blooming results in a longer blooming period or if there is a generally faster blooming period when blooming starts later. Based on the results we can say that early start of blooming resulted in extended blooming period for three sour cherry varieties at the examined production sites. The start of blooming showed the closest relation with the difference of average daytime and nightime temperatures of the 30-day period prior to blooming. Significant relation was also detected with the thermic indexes as well as with maximum temperatures, climatic water balance and the degree of potential evaporation.We examined how weather 30 days prior and during blooming influenced the length of phases. Results showed that precipitation prior and during blooming is in significant relation with the length of blooming. We detected significant relation between daytime and nightime temperature differences and the length of blooming. The nature of the relation indicates that blooming periods were shorter in case of increasing temperature differences.We found that shorter blooming lengths occurred when maximum temperatures averaged between 13.5–14.5 ºC 30 days prior to blooming when examining the relation between blooming length and maximum temperature. If the average of maximum temperatures was below 13 ºC or exceeded 15 ºC during this period, then we could calculate with a blooming period longer than ten days. We proved that little precipitation and high temperature accelerates physiological processes, therefore we could calculate with an accelerated blooming and shorter blooming period.

  • Study of Erwinia amylovora colonization and migration on blossoms of susceptible and tolerant apple cultivars
    15-19.
    Views:
    154

    The stigmata of detached flowers of susceptible and tolerant apple cultivars were inoculated with about 104 gfp labeled Erwinia amylovora . There were no apparent differences in the colonization, multiplication and survival of the bacteria on the stigmatic surface of the culivars. Bacteria were washed down to the hypanthium surface 24 hours after inoculation. The visual symptoms of the infection were the discoloration and shrinkage of the floral parts. The gradual browning associated with the infection appeared first on the surface of the hypanthium followed by the discoloration of the style. The color of the filaments turned into brown only 120 hours after the inoculation. Bacterial cells were not detected in the tissues of the styles and filaments. The traits of the hypanthium surface are of prominent importance in the progression of the infection. The wrinkled surface, the convex shape of the outer epidermal cell walls with thin cuticle and the sunken stomata helped to preserve a water film for a longer period providing medium for the motility of the bacteria in the susceptible cultivar. Bacteria were restricted to small water droplets on the flat and waxy surface of the hypanthium of the tolerant cultivar and only a few were able to enter the tissues.

    Large bacterium aggregations were detected in the intercellular spaces of the parenchyma of the susceptible cultivar 48 hours after the inoculation. In the next period the Erwinia amylovora cells gradually invaded the intercellulars of the hypanthium wall, the wall of the ovary and the pedicel. Low level of bacterium aggregation was found in the intercellulars of the tolerant cultivars. It is suggested that the progression of the infection was inhibited also by physiological factors.

  • Anatomical structure of stem in the above- and underground portions of Rosa rugosa suckers
    89-91.
    Views:
    190

    Comparitive histological studies were made on the underground and the aboveground stem parts of Rosa rugosa taken from one year old suckers. The underground stem parts were characterized with thicker primary cortex, phloem and pith, weaker phloem fibers, wider cambial zone, medullary rays, xylem and phloem rays as compared with the aboveground stem parts. The most marked differences in the underground stem parts were in the wide cambial zone and in the development of some adventitious roots.

     

  • Improved clonal approaches to growing black locust (Robinia pseudoacacia L.) in Hungary: a case study
    53-56.
    Views:
    286

    In Hungary black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species and due to climate change effects its importance is increasing in many other countries. It has some desirable characteristics from both the practical and research standpoints. As a result of a partly new black locust selection programme new black locust clones were improved and a technology was developed for mass clonal micropropagation of juvenile trees. Clone trials with micropropagated plants were established in the country for evaluating the juvenile growth and the stem form of promising black locust clones under marginal site conditions. Significant differences (P<5%) were found for stem form value which partly verified the genetic gain of the selected clones against the common black locust. It was also proved that tissue culture could offer partly new prospects for the rapid mass cloning of selected genotypes.

  • Effect of water supply on canopy temperature, stomatal conductance and yield quantity of processing tomato (Lycopersicon esculentum Mill.)
    13-15.
    Views:
    336

    Tomato (Lycopersicon esculentum Mill.) is one of the most extensively cultivated horticultural crops in the world.Water supply is important for yield quantity and quality. The aims of the present study were 1) to evaluate the canopy temperature and the stomatal conductance on processing tomato substances with different water supply, 2) to investigate the effect of different water supply on yield quantity. There were two irrigated treatments, one of them was the reguralry irrigated plant stand which got 333 mm water during investigated period, including the precipitation and the other was the cut off substance which means the irrigation (drip) was stopped at the beginning of the ripening process and there was a control as well which got 189 mm precipitation. The canopy temperature was measured row by row with a Raytek MX 4 type infrared remote thermometer. The stomatal conductance was measured by Delta-T AP4 type porometer. There were significant differences between the control and irrigated plants according to the water supply which was formulated the canopy values. The plants with a deficient water supply were decreased the transpiration rate, therefore its cooling effect didn’t show up. The regularly irrigated tomato plants’ yield exceeded the unirrigated ones more than twice. It is emerged from the study that the irrigation has a positive effect on the amount of the harvestable yield in this year type.

  • Epidemiological survey of Xanthomonas arboricola pv. juglandis and Gnomonia leptostyla on natural population of walnut (Juglans regia) in eastern Transylvania
    7-9.
    Views:
    2141

    In Romania, walnut Juglans regia L. is an important fruit crop, although most of the fruit production comes from non-grafted walnut trees, which are natural hybrids. Breeding programs have been launched during last 30 years to develop new cultivars with uniform fruit quality. In addition, foreign cultivars have been introduced and tested to establish a valuable walnut genepool. To improve the present assortment of generative rootstocks in walnut and to examine the infestation level, a long term survey was carried out in Eastern Transylvania. The main physical characteristics of fruits and its variation to the infestation level were considered. The cumulative distribution of Xanthomonas arboricola pv. juglandis and Gnomonia leptostyla were relatively low and the maximum value was around 15%. The highest infestation of husk with X. arboricola pv. juglandis was observed for roundish forms and differences were statistically significant comparing with other phenotypes. Infestation with G. leptostyla was similar for roundish, elliptic and thwarting egg-shaped phenotypes, while the husk infestation for egg-shaped phenotypes was not observed. The walnut population studied in our experiment can be considered as a genetically valuable population. More than 20% of them have upper class quality fruits with at least or more than 50% of nutmeat. Do to the large scale climate variation in Eastern Transylvania and the high humidity favourable for pathogen infestations, these population can be considered resistant and well adapted to abiotic and biotic factors.

  • Evaluation of the quality of Sorbus fruits belonging to different species
    37-41.
    Views:
    171

    The interest in wild growing fruits was increased considerably by the pharmaceutical industry, the cosmetics as well as by the food industry. (Stefanovits-Bányai et al., 2004). Elderberry (Sambucus nigra L), sand thorn (Hippophae rhamnoides L.), cornet (Cornus mas L.), dog rose (Rosa canina L. bearing hips) and the Sorbus species (Sorhus ssp.) have been well known medicinal and/or ornamental plants since long. Recently, precious substances have been detected in their fruits, which are indispensable in healthy foods. Several species and micro-species of the genus Sorbus are components of the native flora of Hungary, and the fruit of some of them have been consumed traditionally, however, they are preferably considered as ornamentals. The nursery of Alsótekeres (Balatonvilágos) maintained some 16 clones of Sorbus species, which are mainly apomictic "micro species" of. the collection. In 2003, a comprehensive analysis of sorb fruits born on apomictic micro species was initiated in order to find those, which will be suitable to establish plantations. It turned out that considerable differences exist between the fruits of individual taxa, however, it is largely influenced by seasonal effects. According to physical measurements, a scale of mean fruit masses could be established. As for chemical ingredients of the fruits, those are of special interest, which are involved mainly in anti-oxidant activities of the organisms (calcium, potash, phosphorus, copper, magnesium).

  • Epidemiology of brown rot on two apple cultivars in an organic apple orchard
    49-52.
    Views:
    211

    In a two-year-study, the temporal development of brown rot (Monilinia fructigena) on fruits was analysed in an organic apple orchard on an early (Prima) and one late (Idared) maturing cultivars at Debrecen-Józsa in Hungary. Out of five mathematical functions (linear, exponential, three-parameter logistic, Gompertz, Bertalanffy-Mitscherlich), the three-parameter logistic function gave the best fit to brown rot incidence of all cultivars in both years. Disease progress started at the end of June for cv. Prima and at the end of July for cv. Idared, then disease increased continuously from 6-8 weeks up to harvest in all cultivars. Descriptive disease variates derived from the three-parameter logistic function were used to analyse disease progress. These were: Yf, the final disease incidence; Y55, fruit incidence at day 55; Y95, fruit incidence at day 95; b and q, the relative and the absolute rate of disease progress, respectively; T1.5, the time when disease incidence reaches 1.5 %; M, the inflection point and AUDPC, area under disease progress curve. Descriptive disease variates were significantly different (P<0.05) for cv. Prima compared to cv. Idared, except for the relative and absolute rate of disease increase, b and q, respectively. The largest differences among cultivars were in the values of the AUDPC. Disease progress curves and descriptive disease variates were presented and the practical implications of the results were discussed.

  • Effect of reduced spray programmes on incidences of apple scab, powdery mildew and codling moth damage in environmentally freindly apple production systems
    75-78.
    Views:
    736

    Still a large amount of pesticides and spary applications are used in environmentally friendly fruit production systems; therefore, the aim of our study was first to test the in vitro effeicacy of some fungicides against a key apple disease (apple scab), and secondly to evaulate the effectiveness of reduced spray programmes against apple scab, powdery mildew and coding moth in integrated and organic apple orchards. In vitro efficacy of 7 fungicides (Champion 50 WP, Kocide 2000, Nordox 75 WG, Olajos rézkén, Kumulus S, Rézkén, Rézoxiklorid) and another 6 fungicides (Score 25 EC, Efuzin 500 SC, Systane, Folicur Solo, Zato Plusz, Rovral) approved in organic and integrated production systems, respectively, were tested against apple scab. Altogether four spray programmes were performed i) standard integrated: sprays followed by forecasting systems during the season, ii) reduced integrated: sprays followed by forecasting systems but only 75% of the spray numbers used during the season-long spray programme, iii) standard oragnic: sprays applied every 7–14 days during the season and iv) reduced organic: 60% of the spray numbers used during the season-long spray programme. In vitro results showed that fungicides (with active ingredients of copper and sulphur) applied in organic production showed relatively high percent growth capacity of the apple scab fungus. Rézkén showed the highest and Kumilus S the lowest efficacy against apple scab. Fungicides applied in integrated production showed relatively low percent growth capacity of the apple scab fungus. Score 25 EC showed the highest and Rovral the lowest efficacy against apple scab. Field study showed that reduced spray programmes did not increase significantly scab incidence in the integrated field. However, scab incidence increased significanly (above 30%) in the reduced spray programme for the organic orchard.Mildew incidence was low (below 5%) in both integrated and organic spray programmes. Mildew incidence on both shoots and fruits increased significanly in the reduced spray programme for the organic orchard. Incidence of codling moth damage was affected the most by standard vs. reduced spray programmes. Though incidence remained below 10% in the integrated plots, the incidence was significantly higher in the reduced spray programme compared to the standard programme. Similar results were obtained for organic spary programmes, but the incidence was 10 times higher and the differences among the two programmes were larger.,

  • Growth and productivity of plum cultivars on various rootstocks in intensive orchard
    77-81.
    Views:
    342

    Trees of three plum cultivars (Stanley, Cacanska Lepotica and Althann's Gage) were planted at Szigetcsép experimental station in Spring 1994 and trained to slender spindle with the aim to test their growth, effect of productivity under not irrigated conditions and to evaluate the adaptability of rootstock/scion combinations to intensive orchards. As control, trees on Myrobalan C 162/A (P. cerasifera) seedling are planted. In the trial two rootstocks are from Slovakia: Myrobalan MY-KL-A (red leaf) and Myrobalan MY-BO-1, vegetatively propageted. Further on two French rootstocks, the Marianna GF 8-1: Marianna plum (P. cerasifera x P munsoniana) and the Sainte Julien GF 655/2 (P. insititia) were involved. The Hungarian bred plum Fehér besztercei (P. domestica), which is recommended as apricot rootstock is also tested. Rootstocks MY-BO-1 and Fehér besztercei were planted with cultivar Stanley only. Trees were planted to a spacing of 5x3 m trained to slender spindle with 3-4 permanent basal branches. After yield start (1997) trees have been pruned only in summer, after harvest. In the alleyway the natural plant vegetation is mown, the orchard is not irrigated.

    Based on tree size, vigorous rootstocks are Marianna GF 8-1 and Myrobalan C 162/A seedling, medium vigorous are MY-BO-I and MY­KL-A; vegetative propageted myrobalan plums from Slovakia, while St. Julien GF 655/2 and Feller Besztercei proved to be growth reducing rootstocks. No significant difference between the rootstocks was found in turning to bearing. Under non-irrigated condition at Szigetcsép, cultivar Stanley produced the highest yield per area unit on vigorous rootstock (GF 8-1). The cultivar Althann's Gage produced the highest yield efficiency on Marianna GF 8-1 and they were healthy in the last 10 years. The symptoms of Althann's Gage trees on MY-KL-A rootstock indicate a possible incompatibility. The average fruit weight was significantly influenced by crop load on cultivar Cacanska lepotica, while no statistically proved differences were found on Stanley and Althann's Gage. The Cacanska lepotica trees produced significantly lower yield and larger fruit weight on St. Julien GF 655/2 rootstock. Adaptability to spindle training system depends on vigour of scion/rootstock combination: low or medium vigour cultivars (C. lepotica, Stanley) are good choice for spindle training systems even on vigorous rootstock; while the St. Julien GF 655/2 can be recommended only for vigorous Althann's Gage under our soil and climate conditions.

  • Self-fertility studies of some sweet cherry (Prunus avium L.) cultivars and selections
    21-26.
    Views:
    168

    Fruit set of two sweet cherry cultivars (Alex' and 'Stella' ) and four Hungarian selections have been studied over two years following open pollination, unassisted self-pollination (autogamy) and artificial self-pollination (geitonogamy). Among accessions 'IV-6/240' proved to be self-sterile, while the other five revealed to be self-fertile. Significant differences have been found in fruit set among years and among pollination treatments but not among self-fertile accessions. Fruit set following unassisted self-pollination was significantly lower than of other pollination treatments. Thus pollen transfer is essential for profitable yield in sweet cherry growing.

    There was no significant relationship in the fruit set of open- and self-pollination.