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  • Some aspects of reduced disease management against Blumeriella jaapii in sour cherry production
    49-51.
    Views:
    198

    The aim of this study was to evaluate the effectiveness of reduced spray programmes against cherry leaf spot in integrated and organic sour cherry orchards. 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. Our study showed that cherry leaf spot did not increase above 3.1, 7.4, and 8.9% in 2008, 2009, and 2010, respectively, in the integrated orchards. However, leaf spot incidence was above 20% in all years in the organic field. Reduced spray programme did not increase significantly cherry leaf spot incidence in the integrated field in either years. However, leaf spot incidence increased significanly (above 20%) in the reduced spray programme for the organic orchard.

  • Strategy of the sour cherry verticum in the Northern Great Plain Region Hungary (Analytic study)
    7-31.
    Views:
    213

    Sour cherry growing and consumption grows dynamically around the world. The present volume of 1 million tons will incerase within 10 years with 20-30, or even with 50%. In the world wide sour cherry production, Europe is a decisive factor, i.e. 2/3 of the volume is grown there. Prominent capacities are concentrated in East-Central Europe, mainly Poland, Germany and Hungary. In the future, new concurrent exporters are expected on the European market as Turkey, Iran, Serbia-Montenegro. Hungarian sour cherry production has rich traditions, so the growing techniques and the assortment of sour cherry varieties make Hungary a „Great Power" on this field. Fresh fruit and products developed from sour cherry represent values distinguished as „Hungaricum" on the markets. Sour cherry growing and the path of its products are one of the „pulling branches" of Hungarian fruit growing. Sour cherry occupies 15% of area for fruit growing and 40% within the stone fruits. Sour cherry was grown widely in Hungary, it was grown everywhere as for utilizing waste areas. This is the main reason that yields are low as a mean of 15 000 ha and the volume is low (50-60 000 tons) only. To that poor figure the heavy infections of Monilia contributed substantially in the last couple of years. The two most valid arguments of using the present varieties as the best solution are 1) the cross bred new varieties, and 2) the selections of local, traditional varieties, which substituted the earlier dominant 'Pándy meggy' variety, which had a good quality but yielded poorly. Sour cherry growing of Hungary shifted from the dry regions of the country toward the cooler and more humid regions, where the weather excesses secure a less risky production. The most decisive region is the Norther Great Plain Region comprising Szabolcs­Szatmar-Bereg county, where more than the half of the Hungarian sour cherry volume is produced, and which is bound to increase its production in the future. The majority of sour cherry produced in Hungary is processed, moreover, an important fraction of the exported fresh fruit is also used by the industry. The main importer of Hungarian sour cherry is Germany. The industry manufactures mainly canned products, a smaller fraction will be processed to other products. The expected volumes of sour cherry grown in Hungary in the next 5 and 10-year-period was estimated from data based on the ratio of young plantations, predicted consequences of the global climatic changes, phytosanitary aspects, furthermore, on the development of the technological level. In the region, the volume grown within 5 years, 40 000 t/year will increase within 10 years to 55 000 t/y. The processing in Hungary is not sufficiently differenciated, which is attributed partly to the characters of the varieties, partly to the weaknesses of the processing industry. One of the reasons is the suitability of varieties mainly for canning products. Processed sour cherry products could not be sold at the same price levels achieved by concurrent sour cherry growing countries. The vertical structure of the path of products of sour cherry disposes of adequate processing capacity being ready to be developed or there is sufficient intention of making investments for the purpose of manufacturing special sour cherry products. Significant tasks of development are actual in the field of the ecological and biological conditions of production. Volume and yield security as well as the maturity time and diversification of processing possibilities are the main endeavours in widening the assortment of varieties to be grown in the near future. The main objective in growing techniques is the modernization of phytotechnical procedures, and new solutions of methods of mechanical harvesting and related technical innovations are necessary in the sour cherry verticum. A key question is the effectiveness of phytosanitary procedures with special reference to the Monilia fungus and to the cherry fruit fly as the most important pest. There are two points of break through in the Hungarian sour cherry verticum. On the one hand, meeting the increasing demands in fuits for fresh consumption, on the other hand, the diversification of processed sour cherry products and their introduction to the markets. Both are aiming to increase the competitiveness of the Hungarian sour cherry. For that purpose, outstanding varieties and excellent as well as internationally recognised fruit qualities are ready to be utilized. The most susceptible problems of the Hungarian sour cherry verticum are associated with marketing, alliance of the grower-and processor organisations and their co-operation because no overall integration within the sour cherry verticum has been established yet. Most urgent necessity as well as possibility of changes are felt in the Northern Great Plain Region.

  • Harvest and postharvest brown rot of fruit in relation to early latent infection caused by Monilinia spp. in Hungary
    17-19.
    Views:
    194

    In this study, the effect of early latent infection caused by Monilina spp. on harvest and postharvest brown rot of sour cherry and peach was investigated. Two field experiments were performed in commercial orchards located at Eperjeske on sour cherry and at Siófok on peach in 2013 and 2014 in order to study the possible relationship between the incidence of early latent infection caused by Monilinia spp. and the incidence of harvest and postharvest brown rot. No latent infection was recorded at popcorn phanological stage of the trees at both locations. The maximum incidence was detected during the pit hardening period. There was a positive  correlation between the incidence of latent infection and harvest or postharvest brown rot. The average  incidence of latent infection during the crop season explained approximatelly 20% of the total variation in the incidence of postharvest brown rot.

  • Role of organosilicone surfactant in apple scab control under scab conducive weather conditions
    23-25.
    Views:
    163

    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.

  • Detection of natural infection of Quercus spp. by the chestnut blight fungus (Cryphonectria parasitica) in Hungary
    54-56.
    Views:
    174

    The chestnut blight fungus Cryphonectria parasitica (Murrill) Barr [syn.: Endothia parasitica (Murr) Anderson] caused almost total destruction of the American chestnut (Castanea dentata) and widely spread on European chestnut (Castanea saliva) in many European countries. In Hungary, because this fungus threatens most of the Hungarian chestnut stands, great efforts have been made to delay its spread. Biological control with Hungarian hypovirulent strains of the pathogen seems to be an effective method for saving the affected chestnut trees. Until 1998 the fungus was detected on Castanea saliva only, then on some trees of young Quercus petrea in mixed chestnut forests, which also showed the typical symptoms of blight (Kőszeg and Zengővárkony). Although blight symptoms are not so serious in Quercus spp. than in Castanea spp., it seems that C. parasitica threatens the young Quercus spp. in Hungary, mainly in heavily infected chestnut forests. This is the first report of C. parasitica cankers on oak in Hungary.

  • Epidemiology of brown rot on two apple cultivars in an organic apple orchard
    49-52.
    Views:
    161

    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.

  • High antioxidant - and anthocyanin contents of sour cherry cultivars may benefit the human health: international and Hungarian achievements on phytochemicals
    45-47.
    Views:
    309

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

  • Evaluation of lifespan values of six tree taxa in city streets
    25-27.
    Views:
    284

    The aim of this study was to evaluate lifespan values of trees in tree-row system in the streets of Debrecen in two years (2009 and 2017). Six selected taxa (Pyrus calleryana, Acer tataricum, Sorbus intermedia, Magnolia kobus, Acer platanoides and Crataegus x lavalleei) were estimated for the following lifespan parameters: i) trunk diameter (cm), ii) tree crown size (m), iii) trunk status (in 0-5 grades), iv) tree crown status (in 0-5 grades), and v) estimated tree viability (in 0-5 grades). Our results showed that the largest were achieved for Pyrus calleryana and the lowest for Acer tataricum. The largest tree crown diameters were achieved for Acer platanoides and the lowest Magnolia kobus. The best trunk statuses by 2017 were achieved for Pyrus calleryana and the worst Crataegus x lavalleei. The best tree crown statuses by 2017 were achieved for Pyrus calleryana and the worst for Acer tataricum. The best estimated tree viability status was achieved for two taxa (Pyrus calleryana and Acer platanoides). Overall tree values were 2.73 times higher in 2017 compared to 2009. In summary, this study demonstrated the role of appropriate choice of tree taxa for a tree-row system under city street conditions.

  • Effect of pruning intensity on performance of apple cultivars in environmentally friendly production systems
    65-67.
    Views:
    196

    The two worldwide accepted environmentally freindly production systems are integrated and organic. The two systems shows considerably differences in several practical production technology elements. These effects come forward in generative processes (e.g. flowering, fruit setting) and vegetative features (e.g. growth). The aim of our study was to study the effect of pruning intensity on growth features of cultivars in integrated and organic apple production. In early spring of 2009, we determined two pruning intensities (strong and week) on six scab resistant and tolerant cultivars. Strong pruning resulted in stronger shoot growth for all cultivars compared to weak pruning. It is obvious that pruning intensity had more effect on vegetative performance than conditional differences originates from integrated and organic production.

  • The brown rot fungi of fruit crops (Monilinia spp.): II. Important features of their epidemiology (Review paper)
    17-33.
    Views:
    205

    Plant disease epidemiology provides the key to both a better understanding of the nature of a disease and the most effective approach to disease control. Brown rot fungi (Monilinia spp.) cause mainly fruit rot, blossom blight and stem canker which results in considerable yield losses both in the field and in the storage place. In order to provide a better disease control strategy, all aspects of brown rot fungi epidemiology are discribed and discussed in the second part of this review. The general disease cycle of Monilinia fructigena„M. laxa, M. fructicola and Monilia polystroma is described. After such environmental and biological factors are presented which influence the development of hyphae, mycelium, conidia, stroma and apothecial formation. Factors affecting the ability of brown rot fungi to survive are also demonstrated. Then spatio-temporal dynamics of brown rot fungi are discussed. In the last two parts, the epidemiology of brown rot fungi was related to disease warning models and some aspects of disease management.

  • Preliminary results on salicylic acid treatment on brown rot caused by Monilinia laxa on Jumbo Cot fruit, Prunus armeniaca L.
    37-39.
    Views:
    249

    The effect of salicylic acid on reducing brown rot caused by Monilinia laxa infection in postharvest apricot fruit Prunus armeniaca L. Freshly harvest Jumpo Cot fruit were treated with water as control treatment and other group treated with salicylic acid 2 Mm as induced resistance treatment, Fruits were infected by M. laxa (1 × 10-3spores ml-1) and incubated at 25 oC for 2, 4 and 6 days. Treatment fruits with salicylic acid resulted in direct effect on mycelial growth as in the salicylic acid treatment the growth reached to 45% after 6 days of incubation while in the control treatment it reached to 100%.

  • A review of the orchard management in organic fruit production
    43-49.
    Views:
    186

    The elements of orchard management have a determining role in the success of organic fruit production, therefore, it is essential that they are applied properly. The present review gives describes some aspects of the orchard management such as site selection, orchard soil, rootstocks and cultivars, planting materials and plant density, crown shape. Then, one of the most important elements, pruning is discussed with special emphasis on winter pruning, condition and apical dominance, degree and method of pruning, summer pruning. After pruning, an overview of fruit thinning, irrigation, soil cultivation, soil protection (cover plants and mulching) and fertilization is given.

  • Incidence of virus fungal diseases on three stone fruits cultivars in Hungary
    107-109.
    Views:
    212

    In this two-year study, incidence of Polystigma rubrum on plum, and Apiognomonia erytrostoma on apricot were evaluated on several stone fruit cultivars in Hungary. Results showed that most apricot cultivars expressed symptoms caused by A. erytrostoma, graded between 2 and 3 (10-50%) by the end of the summer in 2005 and 2006. The most tolerant apricot cultivars were Budapest and Mandulakajszi while the most susceptible ones were ’Magyar kajszi’ and ’Piroska’.Assessments made on plum showed that most of the plum cultivars were tolerant or lowly susceptible to P. rubrum such as ’Ageni’, ’Althann ringló’, ’Bluefre’, ’Cacanska najbolja’, ’Silvia’, ’Ruth Gerstetter’, ’Tuleu gras’ and ’Utility’. The most susceptible plum cultivars to P. rubrum were ’Besztercei clones’ and ’Debreceni Muskotály’.

  • Impact of sodium-selenate on the growth of radish (Raphanus sativus L.) seedlings in vitro
    113-115.
    Views:
    156

    Selenium (Se) is an essential trace element for animals, microorganisms and some other Eukaryotes. It has become increasingly evident that Se plays a significant role in reducing the incidence of lung, colorectal and prostate cancer in humans. Although it is well known that some species among higher plants are able to accumulate selenium in their tissues, but others are not able to do so, and there is evidence that selenium is needed for the growth of algae, meanwhile the question of essentiality of Se in vascular plants is unresolved. We aimed to study the in vitro growing and to characterise some physiological properties in radish (Raphanus sativus L.) seedlings treated with 0 to 200 mg/1 sodium-selenate. The results showed that lower (2 mg/1) concentration sodium-selenate increased the biomass as well as the total antioxidant capacity of seedlings. The seedling's selenium content showed linear correlation with the sodium-selenate content of the medium.

  • Evaluation of generative accomplishment of new apple cultivars in Hungary
    11-15
    Views:
    249

    In a two year study, 14 new apple cultivars (cvs ’Gala Venus Fengal’, ’Gala Decarli-Fendeca’, ’Galaval’, ’Jugala’, ’Gala Schnitzer (S) Schniga’, ’Red Cap Valtod (S)’, ’Early Red One’, ’Jeromine’, ’Crimson Crisp (Co-op 39)’, ’Red Topaz’, ’Wilton’s Red Jonaprince’, ’Red Idared’, ’Fuji September Wonder’ and club cultivar) were studied in Eastern Hungary at Nyírbátor. The following parameters were measured: trunk cross sectional area (cm2), harvest time with yield (date, kg/tree, number/tree), fruit size (mm), fruit surface color (%), and color intensity of the fruit surface (1-5). According to our two year assessments regarding, the best generative accomplishment was achieved for the cvs ‘Gala’ sorts trained to slender spindle and the cv ‘Red Jonaprince’ trained to super spindle. According to the trunk cross sectional area the ‘Gala’ sport trained to slender spindle showed the strongest growth among the 4 years old trees, while the cv ‘Fuji SW’ and the cv ‘Jeromine’ presented lower vegetative accomplishment. The ripening time of the cultivars started at the end of August and finished at the beginning of October. ‘Gala’ mutants trained to slender spindle provided the highest yields. Fruit size of all cultivars reached the market required standard, however, cvs ‘Red Jonaprince’ and ‘Red Idared’ produced large fruits over 90 mm. The fruit size of the ‘Gala’ sort was 72–75 mm. Most of the cultivars showed high fruit surface color and color intensity.

  • Brown rot blossom blight of pome and stone fruits: symptom, disease cycle, host resistance, and biological control
    15-21.
    Views:
    807

    In this paper, important features of symptoms, biology and biological disease management are summarised for brown rot blossom blight fungi of pome and stone fruit crops (Monilinia laxa, Monilinia fructicola and Monilinia mali). Firstly, European brown rot caused by Monilinia laxa is discussed highlighting the blossom epidemiology features, then host susceptibility of the most important stone fruit species including several Hungarian and international cultivars. At the end of this chapter, recent biological control possibilities against Monilinia laxa are also included. Secondly, American brown rot caused by Monilinia fructicola is discussed. Symptoms, biological features of blossom blight and host susceptibility of flowers to Monilinia fructicola are demonstrated. Finally, the symptoms and the biology of the least frequent species, Monilinia mali are shown.

  • Pruning and incidences of diseases and pests in environmentally oriented apple growing systems: some aspects
    24-29.
    Views:
    219

    In Hungary, fruit growers are increasingly interested in environmentally oriented growing methods, such as organic and integrated systems. The main factor in creating such systems is the establishment of a system of cultivar-pruning-plant protection based on production technology. Therefore, our aim was to examine the susceptibility of apple cultivars to diseases and pests and the effect of pruning technique on diseases and pests in organic and integrated growing systems.

    Two pathogens (Venturia inaequalis, Podosphaera leucotricha) and two pests (Leueoptera malifoliella, Pannonychus ulmi) were observed in organic and integrated systems under "strong" and "weak" pruning techniques. Our results showed that, compared to integrated production, the pathogens and pests infected the trees more in the organic system. The pruning technique affected mainly the cultivars susceptible to diseases and pests. In general, the "weak" pruning technique correlated with a higher level of damage caused by diseases and pests than the "strong" pruning technique, especially in the organic growing system. The reason that techniques should be carefully chosen is that shoots grow faster and more vigorously after employing the "strong" pruning technique. This supports a better preservation of the trees, as a result of reduced susceptibility of plant tissues to diseases and pests.

  • Disease warning models for brown rot fungi of fruit crops
    19-22.
    Views:
    216

    In this review, disease warning models for brown rot fungi, including Monilinia fructigena, M. laxa and M. fructicola, were summarized. Few studies have been made to relate epidemiology and disease warning in brown rot infection caused by M. fructicola and M. laxa in order to predict infections or develop decision support models for fungicide applications during the growing season. More recently a disease warning model and a decision support system were also performed for M. fructigena for organic apple orchards. This review gives an overview on some details of the above disease warning models and decision support system.

  • Study on the micronutrient content of soil and leaf of an organic apple orchard in Eastern Hungary
    7-11.
    Views:
    160

    The aim of our study was to investigate the relationship between micronutrient content of soil and leaf in an organic apple orchard. The experiment was carried out at the Experimental Site of the University of Debrecen, Centre of Agricultural Sciences at Pallag in an apple cultivar collection in Eastern Hungary in 2002-2004. The soil sampling was carried out twice per year, at the beginning and the end of the vegetation period in 2002, 2003 and 2004, respectively. The micronutrient content of leaf of seven apple cultivars (Jonagold, Mutsu, Idared, Red Elstar, Egri piros, Reka, Remo) was studied according to phenological phases of apple (April — September) to investigate the dynamism of plant nutrient uptake.

    It was found that results of leaf analysis correlated with the obtained results of soil. According to the data of July, manganese and copper content of leaf is in the 'favourable' but zinc is the 'low' range of nutrient supply category. Moreover, there were significant differences in the micronutrient content of leaf among cultivars. From our results it is evident that more reliable data were obtained for fruit nutrition by determining of micronutrient content of soil and plant and calculate their ratios as well.

  • Leaf number and plant height of three Canna x generalis cultivars
    22-24.
    Views:
    243

    The aim of this three-year study was to evaluate the effect of three treatments (thiophanate methyl, charcoal dust, and control) on leaf number and plant height on three Canna x generalis cultivars (City of Portland, Richard Wallace and Robert Kemp). Results showed that the 3-year means of leaf number ranged from 13.9 to 23.1 for the three cultivars. The largest leaf numbers were for cultivar Robert Camp (23.1 in 2010) and the lowest for cultivar City of Portland (13.9 in 2011). Thiophanate methyl treatment produced the highest number of leaves and the values were significantly different at P< 0.05 from the control for all years and for all cultivars. Numbers of leaves in charcoal dust treatments were larger than the control treatments but it was not significantly different. Results on plant height ranged from 69.2 to 160.5 cm for the three cultivars. The largest plant height was for cultivar Robert Kemp (160.5 cm in 2011) and the lowest for cultivar City of Portland (69.2 cm in 2011). Thiophanate methyl treatment produced the highest plant height and the values were significantly different at P< 0.05 from the control for all years and for all cultivars. Plant heights in charcoal dust treatments were larger than the control treatments but it was not significantly different.

  • Organic versus integrated apple growing: II. differences in fruit quality parameters
    61-63.
    Views:
    223

    The aim our study was to establish whether significant differences in nutrients uptake and quality of fruit exist
    between organic and integrated grown apples. The study was performed at the orchard Fruit Research Station, University of Debrecen, at Debrecen-Pallag during 2002–2004. Diameter (mm), weight (g), firmness (N/cm2), dry matter (%) and Vitamin C in fruit were determined. Diameter data showed that the size of apples strongly depended on cultivars and organic apples were larger than integrated ones. Moreover, the effect of year and species strongly affected the apple diameter, size and weight. Measured data of firmness were good agreement in data of diameter and weight. Larger fruits have lower values of firmness due to the structure of fruit flesh. Dry matter content of apples varied between 14.66 and 18.07 in integrated, and 12.87 and 17.29 in organic apples according to cultivars. Values were affected by years and cultivars. From results it was evident that the dry matter content of apples affected by production system. It was lower in organic samples than integrated ones.Vitamin C content of apples was stronger affected by species and years than production system.

  • Actual state of research concerning vitamin C as reflected in the literature (Review article)
    7-15.
    Views:
    162

    Vitamin C (L-ascorbic acid) being essential for many living organisms, including man, became once more into the focus of interests because of its numerous physiological effects. Its anti-scurvy and anti-oxidant properties have already been recognised since long in the human body, but it turned out gradually that it has many other functions. In plants, its primary importance is defense against the photo-oxidative stress.

    The present review is intended to reveal some details of the artificial synthesis of vitamin C. Emphasis is put on the metabolism of L-ascorbic acid in higher plants. Biosynthetic processes, translocation and accumulation are discussed in detail on the basis of recent results published in the scientific literature.

  • Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology
    19-23.
    Views:
    344

    Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle.

  • Incidence of fungal diseases on leaves of apricot and plum cultivars in Hungary
    29-31.
    Views:
    215

    In this two-year study, incidence of Polystigma rubrum on plum, and Apiognomonia erytrostoma on apricot were evaluated on several stone fruit cultivars in Hungary. Results showed that most apricot cultivars expressed symptoms caused by A. erytrostoma, graded between 2 and 3 (10-50%) by the end of the summer in 2005 and 2006. The most tolerant apricot cultivars were Budapest and Mandulakaj­szi while the most susceptible ones were 'Magyar kajszi' and 'Piroska'. Assessments made on plum showed that most of the plum cultivars were tolerant or lowly susceptible to P. rubrum such as 'Ageni', 'Althann ringló', 'Bluefre', 'Cacanska najbolja', 'Silvia', 'Ruth Gerstetter', 'Tuleu gras' and 'Utility'. The most susceptible plum cultivars to P. rubrum were 'Besztercei clones' and 'Debreceni Muskotály'.

  • Possibilities of blossom and twig blight management in organic stone fruit production
    103-105.
    Views:
    196

    In this study, possibilities of environmentally-benign plant protection against blossom and twig blight were summarized for organic stone fruit orchards. Symtomps of Monilinia laxa (Aderh. & Ruhl.) Honey) were described and then cultivar susceptibility to blossom and twig blight was discussed. Several sustainable plant protection methods were selected and discussed in details such as mechanical, agrotechnical, biological, and other non-chemical control possibilities (stone powders, plant extracts and restricted chemical materials).