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• Vegetative and generative properties of two apple cultivars ‘Galiwa’ and ‘Story Inored’ in a multi-row system

  34-38.

  A. Csihon

  I. Gonda

  I. J. Holb

  Views:

  208

  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).

• Effect of foliar fertilization on leaf mineral composition, sugar and organic acid contents of sweet cherry

  45-48.

  P. T. Nagy

  S. Thurzó

  I. Kincses

  Z. Szabó

  J. Nyéki

  Views:

  207

  Influence of a three-year-long foliar fertilization on mineral composition of leaf, content of sugars (glucose, fructose, galactose and sucrose) and organic acids (citric, malic and fumaric acid) of sweet cherry (Prunus avium L.) fruits was studied. The experiment was conducted during 2005-2007 in West Hungary on mature cv. `Germersdorfi 3' grafted on Prunus mahaleb rootstock, planted in 1999. Trees spaced 7 x 5 m, and growing in a calcareous chernozem soil. Trees were foliar-fertilized with potassium (K) as KNO₃ and calcium (Ca) as Ca(NO3)2. Potassium spraying was carried out 3 (K₁) and 5 (K₂) while calcium was applied at 3 (Ca ₁), 5 (Ca₂) and 6 (Ca₃) weeks after full bloom. Beside fruit analysis, complete soil and leaf analysis were done to study the rate of nutrient uptake and its effects on fruit quality. Contents of nutrients of soil and leaf were determined by atomic absorption and spectrophotometric method, while sugars and organic acids in fruit were determined by HPLC. The applied treatments (except K₁) had been increasing leaf K significantly compared to the control till ripening. Most of treatments had no significant effect on Ca content of leaf till ripening. From applied treatments only the boron treatments had significant increasing effect on contents of all examined sugars, compared the control. Furthermore, the effect of calcium spraying on the contents of organic acids was significant.

• Effect of boron nutrition on nutrient uptake and fruit quality of tart cherry in Eastern Hungary

  45-48.

  P. T. Nagy

  J. Nyéki

  M. Soltész

  T. Szabó

  Z. Szabó

  Views:

  252

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

• Floral biology of tree fruit rootstocks

  153-161.

  K. Hrotkó

  Z. Erdős

  Views:

  152

  The modern nursery industry requires seed sources of a high quality and regular quantity year by year. Besides the seed sources of processed cultivars (Bartlett pear, Shipley, Elberta peach) special seed orchards are planted with selected seed trees producing high quality and genetically determined seed (hybrid seed or inbred lines). Seedlings are still the most common commercial source of rootstocks for stone fruits (almond, apricot, peach, plum, prune and walnut). Although clonal rootstocks are spreading, usage of seedlings is still predominant at stone fruits and nuts. For successful seed production and planning of seed orchard the knowledge on floral biology, flower fertility, pollination, blossom time of trees (selected clone or cultivars) used for seed production is essential. In this field very little systematic research was carried out most of the papers were published in the second half of the 20th century. Our mini review gives an overview on the importance of flower fertility in the mating systems applied in seed orchards, and the research results on floral biology of fruit tree rootstocks propagated by seed (Prunus avium, Prunus mahaleb, Prunus armeniaca, Prunus cerasifera, Prunus insititia, Prunus amygdalus, P persica, P amygdalopersica, Pyrus pyraster, Pyrus communis and Pyrus betulifolia) over the last decades.

• Effect of late spring frost event on nutrition aspects of a sour cherry orchard in East Hungary

  93-97.

  P. T. Nagy

  I. Kincses

  J. Nyéki

  T. Szabó

  M. Soltész

  Z. Szabó

  Views:

  249

  Similarly to 2007, 2011 was also critical year for fruit growers in Eastern-Hungary. Serious frost damage was observed at late blooming period (6 May (T=-1.6°C)) in this region, which caused approximately 60-65% of fruit loss. The aim of this study is to investigate the effects of a spring frost event on nutrient uptake and status of the trees of a sour cherry plantation at Újfehértó. The symptoms of frost were observed visually. This visual observation was confirmed by SPAD readings. The frost affected the macroand micronutrient contents of leaves. It was found that the frost affected the nutrient uptake negatively, but the effect of it was not significantly sometimes. It can be stated that the nutrient demand of trees can be supplied only under even worse conditions.

• Floral biology, pollination and fertilisation of temperate zone fruit trees

  7-12.

  J. Racskó

  J. Nyéki

  M. Soltész

  Z. Szabó

  Views:

  363

  The knowledge of blooming, pollination and fertilisation and its use are indispensable in maximizing of cropping potential of fruits in economical fruit production. In attaining maximum yield a greater attention has to be focused on choosing cultivar combinations, and results of experiments on blooming, pollination and fertilisation must be applied carefully.

  To have efficient bee pollination requires attention at the time of designing an orchard. It requires further attention at the time of bloom of any of the fruit-hearing species. Markets demand new types of fruit which forces constant changes in the cultivar composition of orchard. The blooming, pollinating and fertilisation characteristics of cultivars chosen have to be known before an orchard is set up. Apart from the general knowledge of trees considered to be planted, there is a great need to know the flowering, pollinating and fertilization characteristics of each cultivar in detail.

• Resistance Gene Analogs (RGA) as a tool in fruit tree's breeding

  7-15.

  A. Gutermuth

  A. Pedryc

  Views:

  175

  Breeding for pest and disease resistance comes as a major objective behind the fruit traits. To increase the effectiveness of fruit resistance breeding application of the Marker Assisted Selection ( MAS) is advantageous. For generating molecular markers which enable the following of interesting traits basically two methods are available: targeted marker design based on conservative region of already known Resistance ( R) gene sequences or randomly generated markers. The creation  and the application  of  these homology  based  markers  are the object of this review in  the main  temperate zone  fruit species.

• Preliminary results of fruit quality of resistant sour cherry clones in 2014

  31-34.

  B. Vaszily

  Views:

  156

  The richness of Hungarian sour cherry cultivars in the world is unique; they can be consumed in many ways. Sour cherry is a Hungaricum and has excellent fruit quality and nutritional value. Nowadays the demand for chemical-free fruits is increasing. Reducing the number of chemical applications can be achieved most effectively by the use of resistant varieties, technological developments and cultivar innovation. The domestic and international sour cherry breeding programs use almost exclusively the resistant ‘Csengôdi’ clones as a basis. They are mainly Monilinia and Blumeriella resistant and have higher dry matter and antioxidant content. These pathogens influence not only the qualitative and quantitative parameters of the fruits, but may play an indirect role in the deterioration of the overall condition of the trees as well. The cultivation of resistant varieties can greatly reduce the pesticide load of the environment, so we can produce fruit with excellent nutritional value with fewer chemicals. Our aim is the expansion of the sour cherry assortment by introducing new  resistant cultivars. With this we can contribute to the spreading of environmentally sound production technologies and supply “super fruits” to the consumers.

• Abnormalities of the stigma of sour cherry cultivar

  31-33.

  H. G. Davarynejad

  T. Szabó

  Z. Szabó

  J. Nyéki

  I. J. Holb

  Views:

  233

  The objective of this study was to evaluate the ratio of blackness of the surface of stigma of sour cherry cultivars. At the full bloom time of sour cherry 100 new opened flowers were marked in the internal (Inside), external (outside), bottom and upper parts of the crown of each cultivars including sour cherry cultivars ‘Érdi bőtermő', `Debreceni bőtermő', `Kántorjánosi', 'R. clone', 'Petri', Pándy', and 'D. clone'. The trees were replicated four times. The numbers of flowers with black stigma were counted and the percentage of dead stigma was calculated. In addition, tissues of black stigmata were investigated for blossom pathogens by microscopy. After flowering time the fruit set of the marked flowers counted and then percentage fruit set was calculated. Numbers of counted flowers were between 300 and 980 depending on the four position of the tree. Black color of stigma could be seen only on three cultivars (`Debreceni bőtermő', Érdi bőtermő' and 'Petri') out of seven assessed cultivars. The highest numbers of black colored stigma were found on cultivar ‘Érdi bőtermő' which ranged between incidences of 12 and 21%. Black stigma was never able to produce a fruit set. Microscopic examination revealed no pathogens associated with black stigma. Different part of the tree resulted different amount of black stigma. Black stigma was the largest on the outer part of the tree on cv. 'Érdi bőtermő' but also bottom part of the tree also produced larger number of black stigma on cvs. `Debreceni bőtermő' and ‘Érdi bőtermő'. Though symptoms were not typical to frost damage, we believe that black stigma is probably due to environmental factors during flowering. This might be associated with late spring cold coming from the soil surface as the bottom and outer part of the tree was more suffered from the disease.

• Detection and identification of phytoplasmas in peach based on woody indexing and molecular methods

  35-41.

  M. Németh

  I. Ember

  L. Krizbai

  M. Kölber

  R. Hangyál

  J. Bozsics

  Views:

  137

  Symptoms resembling phytoplasma disease have been observed on peach trees in a seed-source plantation of stone fruits in south Hungary quite recently. In this publication we report on the results of woody indexing of symptomatic peach trees on GF 305 indicator in the field and under greenhouse conditions as well as on molecular studies. Phytoplasma infection detected on GF 305 indicators in greenhouse and field indexing was confirmed by PCR. Nested PCR was conducted using universal primer pairs followed by group and subgroup specific primers for the second amplification. RFLP analysis of nested PCR products was performed using Rsal restriction enzyme. Based on the results of molecular studies it can be concluded that phytoplasmas, belonging to the European stone fruit yellows subgroup (16SrX-B) were identified in peach trees. Further studies on symptomatic peach trees originating from different parts of Hungary are in progress.

• The effect of Regalis® (prohexadione calcium) on the reduction of fire blight (Erwinia amylovora) severity in apple trees

  61-66.

  P. Sobiczewski

  T. Bubán

  Views:

  162

  Due to the lack of effective and non-phytotoxic materials for control of the blossom and shoot blight phase of fire blight in pome fruit trees, two novel control strategies have emerged: shoot growth retardation by bioregulators and applying resistance inducer compounds. Prohexadione calcium (ProCa) is the active ingredient of the bioregulator Regalis^® registered in several European countries. The reduction of shoot growth elongation is the most obvious effect of ProCa. Furthermore, it causes significant changes in the spectrum of flavonoids and their phenolic precursors, leading to the considerable reduction of susceptibility to fire blight.

  In Poland, potted one-year-old apple trees of cvs. Gala Must grafted on M.26 and Sampion on M.9 (in 2001) as well as Gala Must on P.60 (in 2002) were treated with Regalis® at a range of concentration of 250, 150 or 150 + 100 ppm, respectively. The inoculation of shoots was made with the strain No.691 of E. amylovora (10⁷ cfu/ml), on the 7th and 21st'day after treatments with Regalis. In Hungary, during the years of 2002 and 2003 one-year-old container grown apple trees of the cvs. Idared/M.9 and Freedom/M.9 were treated with the prohexadione-Ca, the active ingredient of Regalis® 100, 150 or 200 ppm, two weeks before inoculation with the Ea 1 strain of E. amylovora (10⁷ cfu/m1).

  In Poland, the suppression of fire blight in shoots reached up to 80%, depending on concentration and application time of Regalis®. In Hungary, the effect of prohexadione-Ca treatments, determined by the length of necrotic lesion developed, proved to be better than that of streptomycin used for comparison.

• Evaluation of fruit tree waterstress condition and transpiration with heat fl ux sensors

  leaf area index, evapotranspiration, water stress

  A. Nagy

  P. Riczu

  J. Tamás

  Z. Szabó

  M. Soltész

  J. Nyéki

  Views:

  190

  In this study the transpiration properties and response to heat stress of Granny Smith and Jonagold apple species were measured. The examinations were set at an orchard near to Debrecen. The chosen trees were two years old, without fruits, in 20l container, placed in the mixture of mulch matrix, wood chips and sawdust and grown at the same climatic conditions. One of the most important goals was to determine the leaf area of the trees which is a basic data for transpiration modeling. Leaf area was larger (signifi cance level p<0.05) in the upper part of the canopy to achieve larger photosynthetic surface. Jonagold species with less leaf number (–18% compared to Granny Smith) reached almost the same canopy area, than Granny Smith, due to larger leaf area of Jonagold. Another aim was to measure the transpiration rate of the apple trees. The transpiration measurements were carried out by sap fl ow meter. Only a small transpiration difference can be found between species. During the investigation time there were wet and cool as well as dry and extremely hot periods. In the case of dry and extreme hot periods the transpiration is decreased, which causes decrease in transpiration and enhanced the water stress of trees.

• Training systems of fruit trees in Hungary

  123-127.

  M. Soltész

  Z. Szabó

  J. Nyéki

  Views:

  287

  Growing sites and soil conditions of Hungary warrant profitable production of several temperate fruits at elevated levels of quality. The climate of the Carpathian basin is a mixtures of three main climatic zones the prevalence of which may change seasonally: Atlantic, continental and Mediterranean, therefore, growing sites are rather various. Temperature minima of the winter and late spring frosts are the main elements of risk. In choice of the system of cultivation, regularity of yields and intensity are to be observed equally. Regular yields are particularly aimed in stone fruit cultures.

  For apple and pear plantations of high density required for intense production are promoted favourably. Accessories of intense orchards (irrigation, supporting system, rootstocks, phytotechniques, etc.) are important. In peach and plum trees are trained to funnel-shape crowns, in general, intense-types are possible in plum, only. In apricots, a Hungarian speciality, the "umbrella" type of crown is applied, almost exclusively, according to Papp. In sweet and sour cherry, the harvest technique, manual or mechanised, according to the intended utilisation, are determining the form of training.

  Red and black currants as small fruits are grown mostly as bushes or hedgerows without any supporting system designed to facilitate mechanical harvest. Raspberries and blackberries are grown as hedges on trellis. Gooseberry is a special case, being a low, thorny bush difficult to be picked. Thus grafted small trees are attached to a wire-trellis which helps to solve problems of plant protection too.

   

• Floral analysis can be use as an early plant analytical tool to diagnose nutritional status of fruit trees?

  23-27.

  P. T. Nagy

  Views:

  191

  A field experiment was conducted in an integrated apple orchard (Malus domestica Borkh.) established on a lowland chernozem soil in East-Hungary, to investigate if flower analysis could be used to diagnose the nutritional status of the trees. In April 2008, during full bloom, flowers and leaves were collected. Leaves were collected again in August, at the standard sampling time from the same trees. The content of nitrogen, phosphorous, potassium, calcium magnesium and boron were measured in flowers and in leaves. Correlation analyses were carried out to establish the relation s between nutrient contents in same and different plant part s. In flowers the following ratio was found between nutrients: N:P: K:Ca:Mg:B -10: l.35:7: 1.7: I :0,02. From result s it was evident that flower as organ contain significant and comparable amount of nutrients like as leaf. The N, K and Ca content were higher in leaves than in flowers at full bloom. The opposite was true for B. The P and Mg content of flower were quite equal with leaf P and Mg at full bloom . All examined nutrients were significantly affected by cultivars both in flowers and leaves. Significant correlation, was found between flower P and leaf P, flower B and leaf B (P=O.O 1) and flower K and leaf K at blooming time (P=0.05). Significant, but weaker correlation was also found between flower K and leaf K and between flower Mg and leaf Mg al JOO days after full bloom (P=0.05). Moreover, strong, but negative correlation was observed between flower B and leaf B at 100 clays after full bloom (P=O.O 1). Within flowers, the strongest positive correlation was found between Mg and B content (P=O.O 1). Strong positive correlations were also recognised between flower K and flower N, Ca and Mg and between N and Ca in the flowers (P=0.01). The strongest correlation was found between K and P in leaves at full bloom (P=O.O 1 ). Strong significant correlation was observed between N and B in the leaves collected at standard sampling time (100 DAFB) (P=0.01). Strong, but negative correlations were found bet ween leaf Mg and leaf P, K and between leaf N and leaf P at 100 days after full bloom (P=O.O 1).

• Water use of young apple trees related to leaf area development

  61-63.

  T. Lakatos

  T. Bubán

  Views:

  132

  Present paper describes an investigation concerning seasonal water use and foliage area development of apple trees. Sap flow velocity was measured in the trunks of five years old apple trees cv. `Florina'/M.26 by a thermal dissipation (Granier) method from 20th of May to the end of September in 1998. The development of foliage area was estimated by a method including leaf area measurements, recording of leaves and shoot length. The foliage area reached to 70% of the maximum yearly value at beginning of June. The remaining 30% developed to the end of August. The leaf area specific water use was considerable higher in June and July, than in second part of summer. The trends of ET-FAO and water use curves differed mostly in the late season: the ET-FAO curve falls quite in September compared to August, whereas the value of water use was a similar as in August. This insensitivity of ET-FAO in this period may be a great disadvantage while using the Penman-Monteith equation in irrigation scheduling of apple.

• The tests of effectiveness of Frostbuster under excessive weather conditions in an apricot plantation

  87-91.

  L. Lakatos

  E. Ancza

  J. Szél

  M. Soltész

  Z. Szabó

  J. Nyéki

  Views:

  242

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

• Evaluation of the growing and fruit bearing characteristics of the ‘Lapins’ sweet cherry cultivar grafted on rootstocks with different vigor

  15-18.

  Á. Csihon

  K. Bicskei

  P. Dremák

  I. Gonda

  Views:

  394

  Sweet cherry is currently considered as a fruit with high interests. The amount of the produced yield is well saleable in the world and also in Hungary year by year, moreover often there is a shortage with the high quality fruits. Researches with the sweet cherry production focus on the intensity growing all over the world, namely the realization of producing with small trees ensuring high quality and quantity. In our examinations ’Lapins’ sweet cherry cultivar was evaluated grafted on rootstocks with different vigor (Gisela 5, Gisela 6, Colt) at the University of Debrecen, Pallag Experimental Station. According to our results trees grafted on Colt rootstock can be described with very low yields due to the excessive high vigor. Trees with Gisela 5 and Gisela 6 rootstocks showed excessive high productivity, as size of the fruits did not reach the required values.

• DNA-based determination of suitable pollinating cultivars for the pear cultivar 'Carola' (Pyrus communis)

  15-19.

  H. Nybom

  J. Sehic

  H. Mattisson

  Views:

  132

  Pollen-limited fruit set has long been suspected in some relatively low-yielding orchards with the Swedish pear cultivar 'Carola'. Fruit was therefore harvested on 23 'Carola' trees in a commercial pear orchard. The seeds were germinated and five seedlings from each tree were sampled to determine which of the surrounding cultivars had been the most successful pollinators. Leaves of 'Carola', the 7 putative pollinating cultivars and the 115 seedlings were analysed with 6 RAPD primers. By comparison of the band patterns, paternity could be ascertained for 74 seedlings. The by far most successful pollinator was 'Clara Frijs' which had sired approx. half of the seedlings, followed by 'Herzogin Elsa', `Skanskt Sockerpiiron', 'Alexandre Lucas', 'Coloree de Juillet' and 'Doyenne du Cornice'. The latter is the maternal parent of 'Carola', and these two cultivars must therefore share one S-allele and hence can only be semi-compatible. In addition, 6% of the seedlings were in all likelihood derived from selling_ since they showed no bands that did not occur also in 'Carola'. Maximum distance between 'Carola' trees and suitable pollinators should not exceed 15-20 tn. Longer distances may produce a serious dearth of compatible pol­len as evidenced by the large percentage of seedlings derived either from selling. (25%) or from long-distance (> 40 m) pollen transfer (25%) when 'Carola' trees were surrounded by non-preferred pollinators.

• Phyl-Gold: a product to diminish russeting of 'Golden Delicious' apples

  131-133.

  L. Csiszár

  T. Bubán

  F. Takács

  M. Benedictyné Rátz

  L. Oláh

  Views:

  128

  Producing high quality apples in mature trees of the cv. 'Golden Delicious' is rather difficult because of the russeting of it's fruits, especially in seasons of high relative humidity and/or wetness.

  Earlier experiments proved the possibility to decrease russeting by treatments of GA₄.₇ during a period after petal fall.

  Phyl-Gold, a product of Phylaxia Co. (ai. 10 g1^-1 GA₄.₇) was applied to inhibit russet formation in fruit skin of 'Golden Delicious' apples. Four consecutive sprays were carried out (with 10 ppm a.i.) in weekly intervals, starting at petal fall and tank-mixed with the current pesticides of the plant protection program.

  Due to the GA₄.₇ application the russet formation decreased at a rate of economical importance. As for the side-effects of treatments, fruit set was reduced slightly in trees treated, however, there was no consequent influence on return bloom.

   

• Study of genetic resources for Powdery mildew resistance by biochemical and physiological parameters on peaches and nectarines in Romania

  57-61.

  S. Toma

  A. Ivascu

  M. Oprea

  E. Delian

  F. Toma

  M. Zdremtan

  L. Halmagean

  L. Cantar

  Views:

  122

  During 1997-2002, studies on the physiological and biochemical changes due to powdery mildew attack in peach and nectarine cultivars and hybrids belonging to different classes of resistance had been performed at the Research Station for Fruit Tree Growing (RSFTG) Baneasa Bucharest, located in the southern part of Romania. The study was based on disease assessments in the field and on other diagnosis criteria.

  The southern part of Romania has favourable ecological conditions for growing peach and nectarine but trees have been attacked by various pathogens such as Sphaerotheca pannosa (Wallr.: Fr.) Lev. var. persicae Woronichin fungus for a long time. The presence of the pathogen causes important changes in the quantity and quality of fruits and affects the metabolism of trees.

  This study was focused on several physiological and biochemical parameters such as photosynthesis and respiration intensity along with catalase activity; and changes in some biochemical compounds such as free, total and linked water content, dry matter, nitrogen and protein content, tannin levels. The aim was to find possible correlation among the above parameters and the biotic stress induced by the powdery mildew fungus calculated as attack degree (AD%).

  Results showed that photosynthesis diminished significantly in the case of the attacked phenotypes, the respiration was more intense in the infected cultivars and catalase proved to be less intense in the affected plants. The total water content significantly increased in contrast to the dry matter and tannin contents, which greatly reduced in the case of resistant cultivars such as 'Victoria', Vectared 7', 'KB 11-40'. The total nitrogen and protein levels showed less influence on resistance to powdery mildew on all cultivars. All genetic material found resistant to powdery mildew is currently used in peach and nectarine breeding programs in Romania.

  Further studies focused on isolation and characterization of resistance genes for powdery mildew resistance will be done in the future based on data collected during several years.

• A critical evaluation of methods used for S-genotyping: from trees to DNA level

  19-29.

  J. Halász

  A. Hegedűs

  Views:

  176

  Fruit setting behaviour of fruit trees remains to be in the focus of plant breeders and growers. Realizing that most species (cherry, apple, pear etc.) are self-incompatible and certain cultivars are cross-incompatible, mutual fertility properties and their reliable determination are of great interest. This review gives a comprehensive description of all known S-genotyping procedures, i.e. the classical fruit set analysis after open field test crosses; pollen tube growth monitoring with fluorescent microscopy; stylar ribonuclease electrophoresis (using different types of isoelectric focusing and 2-dimension polyacrilamide gel electrophoresis); as well as the most recent polymerase chain reaction based DNA-level analyses and DNA sequencing. The review presented not only gives a compilation of the bases of the methods described but also provides a critical evaluation and a comparative characterization of their applicability.

• Review of the molecular background of self-incompatibility in rosaceous fruit trees

  7-18.

  J. Halász

  A. Hegedűs

  A. Pedryc

  Views:

  193

  This review gives a presentation of the gametophytic self-incompatibility system in the roscaeous fruit trees. Studies to discover the pistil (S-ribonucleases) and pollen-part components (F-box molecules) are summarized and models for the self-incompatibility reactions as well as their molecular background are discussed. We describe how mutations within the S-RNase or F-box genes can contribute to the transition from self-incompatibility to the self-compatible phenotype in many fruit tree crops. The current state of the arts is compared to the information obtained in other plant species possessing similar incompatibility system.

• The impact of location, row direction, plant density and rootstock on the sunburn damage of apple cultivars

  19-30.

  J. Racskó

  J. Nagy

  Z. Szabó

  M. Major

  J. Nyéki

  Views:

  218

  The effect of row direction (N-S, E-W), plant density (conventional and intensive) and rootstock (M9, MM106 and crab apple) on the sensitivity of 41 apple cultivars to sunburn injury was studied at 6 locations (Derecske, Kálmánáaza, Nagykutas, Nagylapos, Siófok, Tornyospálca).

  During the observations the cultivars had rootstock-specific properties in respect of sunburn-susceptibility. Accordingly, the injury was decreased in the order: M9, MM106 and seedling rootstocks. The differences in sensitivity depend on the canopy of trees, caused finally by the growing vigour of rootstocks. Accordingly, the highest value of sunburn injury was observed on M9 rootstock, because this rootstock has a dwarfing effect upon the scion cultivars. Thus, vegetative area of these trees grow very slowly and the foliage is not enough compact to protect the fruit from solar radiation. The size and density of the foliage increased in the order: M9, MM 106 and crab apple seedling as rootstock. Moreover, relationships were demonstrated between the diameter of upper part of the crown, the leaf area, the number of fruits per tree and the injury of sunburn.

  Authors categorized the cultivars in respect of values of sunburn incidence: 1. „Not sensitive", II. „Moderately sensitive" and HI. „Strongly sensitive" categories were constituted. Generally, Topaz and Gala cultivars showed low damage (or were free from symptoms), in contrast to this, Golden mutants suffered relatively much. The most sensitive cultivar was Jonica on all the three rootstocks. We searched for relationship between the fruit quality parameters and the frequency of sunburn. Significant correlation was found in the cases of fruit size and the extent of cover-colour. The latter is interpreted with the fact that the best coloured fruits are found on the periphery of crown as a consequence of more intense irradiation.

• Pál Maliga, founder of the research in floral biology of fruit species in Hungary

  57-60.

  J. Nyéki

  M. Soltész

  Views:

  144

  Pál Maliga founded the Hungarian research in floral biology of fruit species during his more than forty-year-long carrier. Almost all pome and stone fruit species have been covered by his activities, but he also dealt with the fertility of walnut and chestnut. Regularities have been revealed and the methodical studies opened the way to approach and elaborate alternatives for the association of varieties in planning high yielding commercial plantations. In his breeding activity the choice of crossing parental varieties was based on the knowledge in fertility relations. The obtained sour cherry varieties represent the world-wide maximum quality, reliability and security of yields. Hungarian renewed sour cherry cultivation owes its fame and prosperity to those varieties, nevertheless also to the radical knowledge of the biological bases of fertility.

• Preliminary study on micro area based spatial distribution of Monilinia fructigena in an organic apple orchard

  19-21.

  I. J. Holb

  A. Rózsa

  F. Abonyi

  Views:

  185

  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.