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• Organic and mineral fertilizer effects on the yield and mineral contents of carrot (Daucus carota)

  69-74.

  A. B. Kovács

  R. Kremper

  A. Jakab

  A. Szabó

  Views:

  413

  A greenhouse pot experiment was conducted to investigate the effects of ammonium-nitrate, food waste compost, bacterial fertilizer (EM-1) and their combinations on production and nutrient contents of carrot. The study was conducted on a calcareous chernozem and acidic sandy soils in a randomized complete block design with 8 treatments and four replications. NH4NO3 in chernozem soil increased the weight of carrot leaves only, while in sandy soil resulted in reduced yield and highly increased NO3-N content of roots. Sandy soil showed higher response of biomass production to food waste compost application than chernozem soil. The highest carotenoid content of roots was measured with compost treatment. Combined application of compost and NH4NO3 in chernozem proved to be good combination but in sandy soil have turn out to be less favourable than sole compost treatment. Bacterial fertilizer (EM-1) did not cause marked effect on the yield parameters, but caused increased phosphorus content of plant. In chernozem soil the maximum yield parameters were achieved with the combined treatment of ammonium-nitrate+compost+EM-1. In sandy soil the most favourable treatment proved to be the compost treatment. Results suggest that application of food waste compost as a nutrient source could be a promising agrochemical practice especially in soils having low organic material and low nutrient supply.

• Investigation of the Antioxidant Effect of Hungarian White Wines and Tokaj Wine Specialities

  22-26.

  M. Kállay

  Z. Török

  K. Korány

  Views:

  229

  Authors investigated the antioxidant effect of wine-phenolics, expressed as total antioxidant status (TAS-value). This property may play an important role in elimination of the harmful effects of free radicals in human body.

  Independently of their polyphenol composition, special quality Tokaj wines did not show extremely high TAS-values. In Tokaj Aszu wines the total antioxidant status was independent of the "puttony" number but was influenced by the length of aging time.

• Disease threshold for cherry leaf spot incidence on commercial sweet cherry cultivars

  52-54.

  M. Varga

  A. Vámos

  B. Molnár

  I. J. Holb

  Views:

  207

  The aim of this study was to demonstrate the 10% threshold level for cherry leaf spot incidence on 23 commercial sweet cherry cultivars in two training systems. Twenty three cherry cultivars were evaluated in the two training systems with a spacing of 4 x 1 m and with a spacing of 2 x 5 m. Results showed that leaves of many cultivars were heavily infected, e.g. cultivars (cvs) ’Biggareau Burlat’, ’Sunburst’, while others showed low disease incidence e.g. cvs ’Celeste’ and ’Blaze Star’. According to the 10 % threshold level, cv ’Celeste’ proved to be the most resistant cultivar to leaf infection, while cv ’Münchebergi korai’ exceeded extremely the 10% threshold level. Leaf spot incidence was affected by training system on most cultivars. Thirteen cultivars had less than 10% infection in the 4 x 1 m spacing (i.e. they did not reach the 10% disease threshold level). At the same time, only 3 cultivars showed less than 10% infection in the 5 x 2 m spacing.

• The antioxidant capacity of sea buckthorn (Hippophae rhamnoides L.) berries depends on the genotype and harvest time

  27-29.

  N. Makovics-Zsohár

  A. Hegedűs

  É. Stefanovits-Bányai

  R. Rédei

  N. Papp

  Views:

  246

  Berries of sea buckthorn (Hippophae rhamnoides L.) are characterized by increasing popularity due to their presumable healtheffects. The aim of this study was to compare the antioxidant capacity and total polyphenolic content in the berries of six Hungarian grown sea buckthorn genotypes and characterize the genetic variability in this trait. The harvest time of sea buckthorn berries affects the antioxidant capacity and total phenolic contents in berries of three popular cultivars of German origin. Berries harvested in October had higher antioxidant capacity compared with those harvested one month later. The extent of the difference was genotype-specific. Our analysis revealed a nearly 3-fold difference between the lowest and highest antioxidant capacities of the 6 tested genotypes with ‘Leikora’ showing the highest ferric reducing antioxidant power and total phenolic content. The TEAC values ranged between 1.76 and 3.13 mmol Trolox/100g fresh weight with Pető 1 and ‘Frugana’ having the highest values. The results presented in this study demonstrated that Hippophae rhamnoides berries possess in vitro antioxidant activity strongly determined by genotype but also influenced by harvest time.

• Change of Thiamine concentration and amino acid composition during sparkling wine base Production

  62-66.

  B. Pühra (Böröczki)

  M. Kállay

  K. Korány

  Views:

  141

  It has been established, that thiamin content added in 3 mg/I concentration to musts before fermentation resulted in the enhanced storability of sparkling wine base at lower SO2 levels. Fermentation rate is not increased by this concentration and it causes no "thiamine taste" in organoleptic evaluation.

• 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.

• Evaluation of generative accomplishment of new apple cultivars in Hungary

  11-15

  Á. Csihon

  I. J. Holb

  I. Gonda

  Views:

  254

  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.

• Investigation of flowering dynamics of the basil (Ocimum basilicum L.) and its consequences in production

  74-80.

  K. Szabó

  É. Németh

  J. Bernáth

  Zs. Pálnok

  Views:

  158

  The flowering dynamics of Ocimum basilicum L., (a common population maintained at the UHFI) was studied with the aim to create an exact and practically applicable method for definition of phenological phases.

  According to our observation the development of individual flowers of the basil can be characterized by 8 distinguishable phases, which must be considered for description of the actual phenological stage of a spike.

  An accurate model was created for the unambiguous description of flowering process of different flowers within the spike and for the individual plant as a whole. The new flowering index formula is calculated from the number of flowers weighed by their phenological phases.

  The time dependence of flowering is presented by functions fitted to values of the flowering index. The results reflected different patterns of the main inflorescence, the inflorescences formed on the side shoots in the first or in the second half of the flowering period. However, for description of the flowering process of the whole plant, a sigmoid function proved to be the appropriate model.

  The accumulation process of the essential oil could be characterized by the flowering index values. They showed close correlation (r=0.964) at high probability.

  The new method assures an exact definition of phenological phases in basil. Its application seems to be optimal during breeding procedures, seed production and even in production of high quality drugs, according to the requirements of the Good Agricultural Practice (Guidelines for GAP, 1998).

   

• Prospects of mango fruit powder production at farm level and its utilisation during mango off-season in Ghana

  V. O. Edusei

  G. Essilfie

  J. Ofosu-Anim

  F. K. Saalia

  V. Eziah

  Views:

  275

  Mango (Mangifera indica) is an important fruit served to customers as fresh-cut fruit, juice, ice cream and yogurts in many fruit juice joints, restaurants and hotels in Ghana. However, the crop’s highly seasonal and perishable nature is a challenge for food processors and farmers. Preservation of the fruit in dry particulate form can serve as a substitute in off-seasons. The study sought to determine mango fruit powder production prospects at the farm level and explore its potential use as a substitute during the off-season. Farmer groups and food enterprises were therefore interviewed. The study showed that Keitt and Kent varieties were the most cultivated varieties because of market demand and high yield. However, an average annual fruit loss of 29.8% at the farm level was observed. Postharvest extension delivery service to farmers is inadequate, and where available, frequency of contact is irregular. A limited number of farmers received training in fruit processing; and few were engaged in transformational value addition activities but were willing to add value through processing into powder. Probit regression analysis showed that a unit increase in training would increase transformational farm level value addition into mango fruit powder by 22.9%. The majority of the food enterprises source fruits within Ghana while 79% experienced mango fruit shortage in the off-seasons. Only a few of the enterprises used mango fruit-based substitutes to serve customers in off-seasons. Probit regression analysis showed that a marginal increase in processors’ use of substitute significantly (p≤0.05) increased willingness to use mango fruit powder as a substitute by 47%. The study has revealed that local production of mango fruit powder could serve as a substitute to fill the seasonal gap in mango supply and also reduce post-harvest losses.

   

• Effect of variety and cultivation technology on phenols and antioxidant activity of sweet and sour cherry

  59-61.

  A. Sass-Kiss

  M. Tóth-Markus

  H. G. Daood

  D. Bánáti

  J. Nyéki

  Z. Szabó

  Views:

  227

  The goal of the present work was to compare different sweet and sour cherry cultivars and cultivation methods (bio/integrated) with respect to polyphenol content and antioxidant activity. The concentration of total polyphenols ranged between 880–1050 mg kg-1 of fresh fruit, whereas antioxidant activity expressed as TEAC was found to be between 5.4 and 10.3 mmol kg-1 for the sweet cherry cultivars examined. In case of sour cherry the level of polyphenols ranged between 1283 and 3490 mg/kg fresh edible part of the fruit. Antioxidant activity was recorded between 15–32 mmol kg-1 for the different sour cherry cultivars included in this work. After one-month storage at low temperature, the total phenols and antioxidant activity decreased by 2–40% in the sour cherry cultivars studied. The anthocyanin content in cherry cultivars was less (131–312 mg kg-1) than the135–1893 mg kg-1 found in sour cherries. Anthocyanin level was higher in samples produced under organic farming conditions than in those produced with integrated cultivation.

• Knot formation by Pseudomonas syringae subsp. savastanoi on the in vitro shoots of Sorbus redliana

  59-62.

  M. Hevesi

  J. Papp

  E. Jámbor-Benczúr

  Gy. Gazdag

  Views:

  158

  Two strains of Pseudomonas syringae subsp. savastanoi were isolated from Forsythia sp. and Nerium oleander in Hungary in 1997. The effects of growth regulators produced by the bacteria were studied in different experiments. The strains were co-cultured with Sorbus redliana in vitro shoots without being in contact with the plant on solid media. Further culture filtrates in different concentrations were added to the culture medium. The growth regulators presented in the agar caused knot formation on the shoots and on the leaves in both kinds of culture. There were significant differences in the cultural and physiological characters, auxin and cytokinin activity of the strains of different origin.

   

• Performance of sweet cherry cultivars grafted on Colt rootstock

  7-10.

  Á. Csihon

  D. K. Bicskei

  P. Dremák

  I. Gonda

  Views:

  609

  In this paper growing characteristics and fruit bearing parameters of ‘Lapins’, ‘Kordia’, ‘Sweetheart’ and ‘Regina’ sweet cherry cultivars grafted on vigorous Colt rootstock were evaluated at the University of Debrecen, Pallag Experimental Station. Based on our data five years old trees can be described with homogenous strong growing, but very week yielding (2.1-3.1 kg/tree), as while fruit size varies between 26.2 and 27.2 mm. Producing the examined cultivars on Colt rootstock with high plant density requires higher attention and more interventions (root pruning, sawing the trunk) during the technology.

• Apple allergens as affected by cultivation technolog and variental factors

  91-93.

  K. Takács

  J. Szamos

  E. E. Szabó

  Z. Szabó

  J. Nyéki

  É. Gelencsér

  Views:

  211

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

• Content of mineral- and sulphur compounds in Hungarian and French garlic varieties

  61-65.

  J. Iváncsics

  Cs. Gombkötő

  N. Gombkötő

  Á. Máthé

  Views:

  213

  In our days about 2 million tons of garlic are grown in the world. Garlic was used as medicine already in ancient Egypt. It contains approx 33 sulfur compounds, several enzymes, 17 amino acids and minerals. We determined the content of diallyl sulfone, boron, calcium, copper, iron, potassium, magnesium, natrium, phosphorus and zinc in fi ve garlic varieties (3 French, 2 Hungarian). We searched if there were signiffi cant differences between the varieties.

• The effect of storage to optical properties in case of two apple fruit varieties

  33-36.

  A. M. El Shal

  P. Riczu

  A. Nagy

  E. Sulyok

  Z. Szabó

  J. Nyéki

  Views:

  235

  The keeping quality of fruits is a very important factor in storage point of view, since it could be elongated the consumption time of fruits. In many cases the storage may be necessary, e.g. in short time it is not able to market due to the rich harvest, or all fruits could sell in markets throughout the year. The keeping quality of various fruit species is greatly different; moreover it could be observed some differences between the varieties as well. In our research, we have investigated the spectral properties of the external surface and fl esh of two ripe apple varieties – Jonagored and Granny Smith – before and after storage (about 3°C and about three weeks). The hyperspectral investigation was carried out with AvaSpec-2048 Fiber Optic Spectrometer. The experimental results represented the differences between healthy and chilling injured apple fruits. Furthermore, some indices were created to given countenance to the spectral differences.

• Antioxidant capacity, total phenolics and mineral element contents in fruits of Hungarian sour cherry cultivars

  59-64.

  N. Papp

  B. Szilvássy

  Z. Szabó

  J. Nyéki

  É. Stefanovits-Bányai

  A. Hegedűs

  Views:

  355

  Several epidemiological studies revealed that the consumption of antioxidant compounds and the risk of atherosclerosis, increased blood pressure or cancer are inversely proportional. Fruits of sour cherry contain a wide range of antioxidant compounds including melatonin, perillyl alcohol, ellagic acid, several flavonoids, polyphenolics, and anthocyanins. This study was carried out to survey the antioxidant power and mineral element content of seven commercial sour cherry cultivars and three cultivar candidates and to assess the influence of some external conditions on fruits' functional properties. Our analysis revealed nearly 5- and 2-fold differences between the lowest and highest antioxidant capacities and total phenolics content, respectively. Some cultivars (`Kántorjánosi' and ‘Újfehértói fürtös') and cultivar candidates (D, 'Petri' and 'Éva') showed outstanding antioxidant capacity and total phenolic content; in addition, mineral element content in fruits of the ‘Újfehértói fürtös' cultivar was also favourable. Redox parameters of fruits were influenced by the cultivation plot or fruit positions within the canopy in about half of the cultivars tested. Genetic background of cultivars forms the decisive factor in determining fruits' antioxidant capacity, although external factors may have also sizeable modifying effects. Enhanced functional properties of the fruit may also be further increased through breeding programs since considerable variation exists within the tested germplasm.

• Identification of plant taxons by isoelectric focusing

  65-67.

  É. Stefanovits-Bányai

  L. Boross

  J. Bernáth

  I. Kerepesi

  M. Kiss

  S. Lakatos

  Views:

  158

  Differences were demonstrated in esterasei coenzyme pattern of some essential oil producing plants belonging to the Apiaceae family — fennel (Foeniculum vulgare Mill.), angelica (Angelica archangelica L.), lovage (Levisticum officinale Koch.), dill (Anethum graveolens L.), coriander (Coriandrum sativum L.), anise (Pimpinella anisum L.), caraway (Carum carvi L.) — as well as differences between two varieties of fennel seed by using isoelectric focusing. That method provides quality control in essential oil plants and is suitable to describe isoenzyme pattern characteristic for taxons.

  Based on our findings, isoelectric focusing seems to be suitable for identification and differentiation of different plant samples, providing an easy tool for further processing as well as for breeding.

  Our further aim is to apply that method to differentiate among samples belonging to the same species according to their value of inner content.

   

• Growth and yield of sweet cherry trees on different roostocks

  98-101.

  K. Hrotkó

  L. Magyar

  G. Simon

  Views:

  225

  The first nine years' results of sweet cherry rootstock trial from Hungary are presented with the aim to select efficient rootstocks for the local ecological conditions. The trials were established in 1989 with 'Van' and 'Germersdorfi óriás' cultivars on the following rootstocks: mahaleb Sainte Lucie 64, Colt, MxM 14, MxM 97. All the trees were headed at 80 cm and trained to a modified Brunner-spindle system. Tree size and yield was measured every year, and the cumulative yield efficiency was calculated.

  Based upon the results, mahaleb cherry SL 64 is a vigorous rootstock with good compatibility and productivity. In comparison to SL 64. the trunk cross-sectional area and canopy spread of the 'Van' trees decreased by 10-15% on rootstock Colt, while the trees of 'Germersdorfi orias' on Colt roostock grew even larger than on SL 64. Considerable 30-40 % reduction of tree size was achieved on trees grafted on M x M hybrids. Trees of `Germersdorfi óriás' showed a similar tendency without significant differences. The cumulative yield efficiency of `Van' trees after nine years was highest on rootstock MxM 14, followed by Sainte Lucie 64. Trees on Colt and MxM 97 rootstocks showed low productivity. `Germersdorfi óriás' produced the highest cumulative yield efficiency on SL 64, followed by MxM 14 and Colt and last MxM 97. Biennial bearing index of heavy cropping 'Van' trees was smaller than that of `Germersdorfi óriás'. The trees of 'Van' on MxM 97 showed higher biennial bearing index, while 'Germersdorfi orias' on different rootstocks showed similar tendency, but without significant differences.

  MxM 14 and MxM 97 rootstocks reduced the crotch angle of the shoots on both sweet cherry varieties which is disadvantegous to spindle training. Slight suckering (1-3/year) of the rootstocks Colt, MxM 14 and MxM 97 were observed during the first few years.

• Effect of a nanotechnology-based foliar fertilizer on the yield and fruit quality in an apple orchard

  29-32.

  Á. Csihon

  I. Gonda

  I. J. Holb

  Views:

  505

  Nutrient management is a determining element of the technology in fruit production. Significance of foliar fertilization has been increased continuously over the last years, as it can improve directly the vegetative and generative performance of the trees. In this study we aimed to evaluate the effect of a nanotechnology-based foliar fertilizer (Bistep) with 1, 3, and 5 l/ha dosages on the yield and fruit quality parameters in an apple orchard during 2016 and 2018. According to our results, crop load increased with 29% in the third year of the experiment with the application of 5 l/ha Bistep treatment compared to the control treatments. Fruit weight was also improved in each year, as values of fruit weight in all treatments were higher than the control one (3.0-13.0% growth). Fruit surface color increased with 2-18% due to the foliar fertilizer. During the three years, leaf length was 9.5-9.9 mm on the control trees, as 9.8-10.4 mm was measured on the fertilized ones. In conclusion, yield and fruit quality can be improved in apple orchard using a nanotechnology-based foliar fertilizer.

• Irrigation management of a peach orchard

  19-24.

  A. Nagy

  P. Riczu

  J. Tamás

  Z. Szabó

  J. Nyéki

  M. Soltész

  Views:

  222

  The research field was at Siófok, in Hungary, which is situated in the South East side of Lake Balaton. The physical characteristic of the soil is sandy loam and loam and the peach orchard is irrigated. Mainly Sweet Lady (early ripening), Red Heaven (medium ripening) and Weinberger (early ripening) species were installed. In order to achieve the optimal developement level of trees and maximal yield amount and fruit diameter (Sweet Lady 60–75 mm, Red Heaven 60–70 mm, Veinberger 50–60 mm) continous water and nutrient supply is required. The irrigation modeling was set by CROPWAT 8.0 based on the climatic, crop and soil data inputs of the last 10 years. Based on the results, large amount of water is needed for optimal growth of fruit trees, particularly in the summer months, in case of active ground cover (+) and bare soil (–) as well. The irrigation requirement of a tree was found maximum 4 l/hour in certain cases. This irrigation intensity can be achieved – calculated with 12-hour operating time – by using continuous water NAAN Tif drip tube with 2 l/h flux on 3 atm pressure with 16 mm pipe diameter. If lower irrigation intensity is required irrigation can be controlled by the decreased the operation time.

• Investigation of the Relationship between the SO2 Production of Different Yeast Strains and Thiamine Concentration

  57-62.

  B. Pühra (Boróczki)

  M. Kállay

  K. Korány

  Views:

  137

  Our general conclusion was that the thiamine amounts of 0,6 and 3,0 mg/1 added prior to wine fermentation, resulted in higher free-S0₂ level in comparison to the control. Furthermore, among the yeast strains examined in our experiments, Uvaferm BC strain produced the highest free-S0₂ content under the conditions mentioned before. As regards the dynamics of reductone and SO, production, the concentration of the previous one was practically identical in the middle and at the end of the fermentation while the SO₂ content — both free- and total — was lower at the end. Thiamine addition did not cause any difference in the organoleptic properties of wines as proved by sensory analysis.

• Sensory evaluation of white asparagus (Asparagus officinalis L.) hybrids

  51-55.

  M. Takácsné Hájos

  T. Rubóczki

  M. Szutor

  Views:

  308

  Comprehensive system of sensory evaluation was developed to obtain information on the different varieties by determining asparagus quality parameters. 9 sensory characteristics were estimated to describe flavour differences. The tests were carried out in 4 varieties of white asparagus (Asparagus officinalis L.) grown on brown humus sand soil by etiolate method in ridge cultivation. The experiment was performed at the University of Debrecen in Debrecen-Pallag. To increase the Hungarian asparagus consumption, a classification of varieties
  regarding to asparagus flavour is necessary. In our experiment it could be stated that there are strict correlations (0.892) between the sweetness – total impression and between lacks of unpleasant aftertaste – total impression (0.870). The result of surveys can lead to higher popularity of the asparagus. These results are presented in order to recommend the varieties to producers for a successful marketing. The taste of asparagus is mostly influenced by variety, soil type and growing conditions. In our experiment, ‘Vitalim’ hybrid exceeded by several sensory parameters. This hybrid scored 788.38 over 900. The elder population showed more interest in asparagus consumption than younger ones. 50% of the participants are able to pay only 500-600 HUF/kg. It could be realized to ensure the proper growing place, hybrid and direct trade. Marketing and more information is necessary to increase the popularity of this vegetable among the younger generation.

• Relationship between several meteorological factors and phenological features of pear cultivars

  67-73.

  L. Lakatos

  T. Szabó

  G. Kocsisné Molnár

  J. Racskó

  M. Soltész

  Z. Szabó

  J. Nyéki

  Views:

  198

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

• 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.

• Partial and total rejuvenation pruning of sour cherry trees

  11-15.

  Á. Csihon

  P. Dremák

  I. Gonda

  Views:

  279

  Sour cherry can be considered as a special fruit species regarding the growing characteristics, as most of the cultivars are characterized by strong balding. With the aging of the tree the inactive (passive) parts of the canopy are increasing steadily, so the productive cropping surface and the yielding capacity decrease  significantly. In our experiments partial rejuvenation pruning was carried out in a 12 years old orchard, and total rejuvenation pruning was performed in a 21 years old plantation to regenerate the cropping surface of the trees. Thanks to the latter one the canopy of the sour cherry trees were regenerated during only two years. The yields of the rejuvenated trees in cv. ‘Debreceni bőtermő’ exceeded the yields of the control trees, as in the case of the cvs. ‘Érdi bőtermő’ and ‘Újfehértói fürtös’ approached it. At the same time the total rejuvenation pruning has a positive effect on the fruit size.