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Pollen morphology of fruit species
49-57.Views:1206Size and surface morphology of pollen has been studied in 87 twit varieties of 10 fruit species during the period of 1990-1995. No preceding work of that type came to our knowledge, yet.
The samples comprised a wide variety of cultivars included male sterile, self-incompatible, partially self-fertile stone fruits, diploid and hexaploid plums, diploid and triploid apples.
The large number of species and varieties facilitated the comparison of items within and between the respective species.
It was stated that the size, shape and surface morphology of pollen is genetically determined and those data, combined with other variety characters, are suitable for the classification and distinction of varieties.
In assessment of pollen size and shape, their moisture content is crucial. The major diameter of the swollen pollen as well as the length and width of the dry grains are characteristic to species and/or to variety.
The width and shape changes largely with moisture content. Large grains are proper to quince, apricot, peach and almond, medium sizes are found in apple, sweet cherry, sour cherry, European plum, whereas small size is typical to Japanese plums.
The low number of varieties studied does not allow conclusions concerning differences within pears, quinces and almonds as species. In the rest of species, valid differences have been registered as between varieties.
Within species, as apple and plum, the effect of ploidy (i.e. number of chromosomes) was expressed in the size of their pollen. In stone fruit species, the correlation between size. of anthers and size of pollen grains was positive.
Genetic relations between the self-fertile sour cherry varieties of the Pándy type (Debreceni bőtermő, Kántorjánosi, Újfehértói fürtös) as well as the self-incompatible apricots of "giant" fruit size are supposed to be analysed by pollen studies but there did not turn out any decisive conclusion, yet. Other characters also should be considered.
The assembly of pollen characters is decisive in the determination of the variety. The ratio of empty pollen grains, the grain size and the density as well as the size of the pits on the surface are best suited to distinguish pollen lots.
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Association of European plum varieties in the orchards
21-24.Views:282The flowering phenology, blooming time and inter-fertility relations of 63 European plum varieties has been studied at growing sites with different ecological conditions during a 10 year long period. The purpose was to develop a system of variety combinations which approaches an optimum in fertility as long as inter-fertility relations will cease to be a limiting factor of yield. According to their blooming time, varieties are assigned to 5 groups: very early, early, medium, late and very late. As for their fertility relations, four groups are formed: self-sterile (0%), partially self-fertile (0.1 to 10 %), self-fertile (10.1 to 20 %) and highly self-fertile (more than 20 % fruit set with self pollination). The four categories of fruit set at free pollination are also relevant to the grower: low (less than 10 %), medium (10 to 20 %), high (20 to 40 %) and very high (more than 40 % fruit set).
By artificial cross pollination, one combination Cacanska najbolja x Stanley proved to be mutually inter-incompatible. Blocks planted to a single self-sterile variety flanking a pollinizer variety proved the spacial distribution of the pollen. The reduction in fruit set was already apparent in the second row away from the pollinizer trees. In a large plantation, without bee hives, relatively low yield was stated on self-sterile trees even close to the pollinizer.
In the case of self-sterile and partially self-fertile varieties, a combination of three varieties is recommended. The blooming period of the pollinizer variety should overlap the period of the self-sterile variety at least by 70 %, and the distance should not exceed 15 to 20 meters. Association of self-fertile varieties may also enhance the productivity of the trees. In that case an overlap of 50 % in blooming time and a maximum distance between the varieties of 30 to 40 meters will be sufficient.
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Possibilities and limits of use plastic constructions in fruit growing technologies
71-75.Views:268On the Experimental Station Pallag of Debrecen University different combinations of fruit species and rootstocks have been raised under and without plastic foil cover in 2002. The growth and productivity of the grafts was our objective of comparison. Results revealed substantial differences in fruit set and yield depending on species and varieties. Sweet and sour cherry varieties grew much shorter under the plastic cover, whereas apricots, peaches and plums set fruit much more eagerly compared with the trees outside the plastic cover. Outside the plastic cover, the trees were much more developed at the beginning of their fruiting period. In spite of that, the growing processes were more intense under the foil. The differences are allegedly due to the repeated summer pruning necessary under the restricted space of the foil, on the other hand, due to the root concurrence because of the dense planting. Regarding the inner properties of the fruits, soluble solids, sugar and acids were higher outside, whereas macro- and mezzo-elements (P, K, Ca, Mg) were more abundant in fruits grown under the foil cover. Further efforts to explore those relations with other varieties and rootstocks are justified.
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Effects of meteorological factors on fruit qualities of 'Fuji' apple in Korea
20-23.Views:109'Fuji' apples from five different growing regions in Korea were analyzed for internal and external quality attributes which included fruit shape, color and sugar. Significant relationships were observed between final fruit color (a*) and air temperature in August. Red color was poorly developed where the average temperature in August was over 25 oC. The sugar composition was significantly different depending on region. The sucrose content decreased with increasing temperature above 16 oC during the harvest season. The fruit shape was not affected by agro-climatic conditions in this study.
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Fruit injury in organic fruit production and its relationship to brown rot caused by Monilinia spp.
7-9.Views:237In a two-year Hungarian study, the temporal progress of brown rot incidence and various injury types were studied in organic fruit orchards and the relationship between brown rot and injury types was determined. Results showed that brown rot reached an almost 20% incidence level in both years. Total injury incidence reached up to 5.3 and 19.8% in the two years. In all cases, insect injury incidence was the highest among injury types in most assessment dates. Incidence levels of other injury types (bird injury, mechanical injury and other injury) began to increase, but none of those reached levels >4%. Pearson’s correlation coefficients showed that brown rot incidence correlated significantly with the incidence of insect injury. In addition, brown rot incidence and the incidence levels of bird injuries was also significantly correlated. High injury and brown rot incidence levels suggest further improvements on organic fruit protection.
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The expression of the primigenic dominance in the flowering and fruit set of selected apple cultivars on different growth inducing rootstocks
27-31.Views:267Authors investigated the expression of the primigenic dominance in the flowering and fruit from open and self pollination of four apple cultivars ('Gala Royal', 'Golden Smoothee', Pink Lady' and 'Vista Bella') during two consecutive years in Western Hungary on three different growth inducing rootstocks (M. 9, MM. 106 and seedling). There were not significant differences in the effect of the rootstocks on the flowering order in a flower cluster. Significant difference in the fruit set in open pollination was found among individual flowers in a cluster, mostly between the king bloom and the second flower. The rate of the fruit set from self-pollination was very low without any significant difference among individual flowers in the cluster.
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Preliminary results of fruit quality of resistant sour cherry clones in 2014
31-34.Views:167The 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.
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Damages caused by winter frosts, their temporal variation and frequencies in the main fruit growing region of Transdanubia and of the East Tisza regions of Hungary
89-97.Views:251The aim of the study was the study of winter frost damages, especially their changes expressed in temporal frequencies on the main fruit growing regions of the country. In our earlier paper, we introduced the calculation with the term LT50 as the quantitative expression of temperature threshold, when the lethality halves the survival of plant organs, buds or cells causing 50% death rate. The damage is highly dependent on the temperature and on its duration (length of time), but not at least on the frost tolerance of the fruit trees. The incidence and severity of damage is analysed according to the apricot and peach varieties of their different susceptibility or tolerance too. Four fruit growing regions, two of the in Transdanubia and two belonging to the regions east of the Tisza river have been selected to trace the incidence and severity of frost damages. For that purpose, we analysed the history of the past 60 year period, 1951–2010, utilising the database of the network of 16 meteorological stations of the countrywide service. Being aware of the values of LT50 during the rest period and afterward, the compulsory dormancy caused by low temperature, the number of days, the probability of frost damage could be predicted. The role of the orographical profi le, the height above sea level and the exposition of plantations are also decisive. Within the same plantation, 20–30 m difference of level may cause large diversity in temperature and frost damage. Air circulation and regular incidence of winds within the Carpathian basin modify the occurrence and severity of damages. Lowlands near the southern and northern country borders are particularly exposed to winter frosts. Most damages are reported in February, as temperatures below –20 °C especially if the fi rst part of the winter was mild, or in January was a warm period. With the end of the physiological rest period of the trees, the frost-susceptibility increases signifi cantly, and a cold period of –15 °C may cause heavy damage. This study proves that tolerance of varieties infl uence the damages substantially. By planting frost tolerant varieties, winter frost damages could be diminished by 40–50% at the same growing sites. Present results may also offer a tool to estimate the risk of frost damages and express the security of yields at a given site based on the data accumulated in the database over many years.
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The application of A HEAT SUM MODEL for the budburst of sour cherry varieties grown at Újfehértó
105-112.Views:320Experiences of the last decades showed univocally that the climatic changes, especially the warming up, influenced clearly the phenology, i.e. speed of growth and development of plants. To check the effects, the phenological studies became a topic of special interest. Our research has been performed at Újfehértó, the Research Institute of Fruit Growing and Extension, where the respective database accumulated observations during the period 1984–2005, where the meteorological data as well as the parallel phenological diary referring to the varieties ’Újfehértói fürtös’, ’Kántorjánosi’ and ’Debreceni bôtermô’ during the period 1984–1991 have been utilised. The method of calculating the sum of daily mean temperatures, “degree days”, is based on the observation that the plants are able to utilise cumulatively – in growth and development – the temperature above a set basic temperature. Our phenology model examined the correlation between the sum of degree days and the date of sprouting (budburst). The basic temperature has been determined by optimization, above which (threshold temperature) the accumulation of daily means was most active, or alternatively, below which the daily means are most sensitively expressed in the phenology. The model has been extended to the calculation of the end of rest period (endodormancy) – by optimization as well. Our phenology model will be suitable for two main purposes: for estimating the time of budburst for the Hungarian region during the next decades calculated on the basis of regionally downscaled climate models; on the other hand, by applying our model, the risk of damage caused by spring frosts could be estimated more exactly than earlier.
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Abnormalities of the stigma of sour cherry cultivar
31-33.Views:297The 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.
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Variety specific integrated fruit production development in order to optimize inner content values
27-31.Views:193In this paper we introduce our results of three years (2007-2009) investigatio ns carried out in the framework of "Research and development in foodstaff chain" - project of Regional University Knowledge Center by the members of Corvi nus U niversity of Budapest - Department of Pomology and. Research Institute for Fru it growing and Ornamentals. Budapest-Erd. The main objectives of the project were the followings: submi ssion of sour cherry candidate suitable for industrial process for state approval; determination of physica l parameter and inner content value changes of sour cherry varieties duri ng ripening; evaluation of health care attributes of sour cherry fruit; ripen ing process description by the colour and the force required to pick fruits of sour cherry. We stated that the optimal begi nning and period of the harvest can be determined wi th the fruit removal force. In this period the fruit growth stops. ju iciness rat io does not change. refractions are approximately equal.acidic content turns to decreasing trend.However the proportion of anthocyan in and polypheno l can still increase. Fruits harvested in this period fulfil a wide range of industrial process opportunities. 'Erdi jubileum ·and candidate IV-3/48 according to their inner content values arc suitable for high quality products (containing real fruit material in high proportion).
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Flower characters and self-fertilization capacity in relation to the bee pollination at sour cherry cultivars
121-132.Views:210Detailed studies and comparisons were carried out on those flower characters of sour cherry cultivars that may affect bee pollination of flowers. Flower characters of sour cherry are fairly similar to other temperate zone fruit tree species. Their relatively small flowers distinguish the Cigánymeggy-types of cultivars from the flowers of tart cherries cultivars that are conspicuously larger, almost as large as the sweet cherry flowers. The relative position of flower organs was much more variable according to the season than according to the cultivars. So the differences were rather the consequences of seasonal effects than of variety features of sour cherry cultivars. As far as individual cultivars are concerned differences in the nectar production and the sugar concentration are revealed rather between groups of cultivars than between individual cultivars. The pollen production of flowers was extremely changeable in consecutive years. Most honeybees collected nectar at sour cherry flowers; pure pollen gatherers and mixed behaviour bees were half as frequent but differences among the behaviour of honeybees according to cultivars cannot be stated. The fidelity of honeybees to sour cherry is less expressed than to some other fruit tree species. Accordingly, it is very strongly suggested to take the competitive effect other plant species (weeds) flowering in and around the orchard carefully into account when organizing additional bee pollination in sour cherry plantations. Several sour cherry cultivars possess more or less self-fertilization capacity but this is greatly changeable according to the season. It has been proved that self-sterile sour cherry cultivars are sensitive even on the partial restriction of the effective time of bee pollination and it is to be stressed too that even in the case of partly self-fruitful cultivars bee pollination is also vital in yield formation because medium or strong restriction of the effective bee pollination period is of a definite negative effect on their fruit set and yield. In years with unfavourable weather the yield can dramatically be reduced sometimes down to nil. However, very high fruit set is also unfavourable because a negative correlation was detected between the final set and the mean mass of fruits.
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Susceptibility of European pear cultivars to Venturia pirina Aderh. infection at a variety collection in Hungary
41-47.Views:293Field sensitivity of 271 European pear genotypes were evaluated in a large variety collection of pear in Hungary during a nine years survey. Substantial differences were detected in the rate of pear scab infection of leaves and fruits. Some 18 per cent of the inspected genotypes remained completely free of infection even in the years with weather favouring to the disease. On the other hand, 78 % of the inspected genotypes were infected in some or more extent. The rate of infection was generally higher on leaves than on fruits. 18.6 % of the genotypes inspected were tolerant to leaf infection and their majority (81.1 %) were tolerant to fruit infection. Some one fi fth of the genotypes (19.7 %) were highly susceptible to leaf infection but only minor rate of them (2.2 %) were highly susceptible to fruit infection. There were 44 genotypes that could be regarded as tolerant to pear scab leaf and fruit infection under fi eld conditions. Some of these genotypes may be suitable to commercial pear growing with highly reduced chemical control against pear but their yield capacity and fruit quality should be evaluated.
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Influence of pesticide use on flower formation and fertility of some fruit species
103-106Views:269This review evaluated previous studies on the effect of pesticide use on flower formation and fertility of some fruit species. The study was divided into two parts. First part of the overview will evaluate the most commonly used fungicides on pollen toxicity and their germination ability under fungicide exposure on different fruit species. Effect of fungicides on fruit set was also critically reviewed. Second part of the study summarised those few studies which determined the effect of some insecticides and acaricides on flower formation and fertility.
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Fire blight (Erwinia amylovora) susceptibility of old Hungarian apple cultivars
35-38.Views:177The aim of the Hungarian apple breeding program started in the Department of Fruit Science was to find resistant apple cultivars against major diseases (scab, powdery mildew, fire blight). The outbreak of fire blight (Erwinia amylovora) in 1996 motivated us to search new resistant sources principally from old traditional apple cultivars. First of all, cultivars have been gathered since 1997 from Carpathia (Visk) and evaluated between 2001 and 2003. In this recent study evaluation of resistance of old Hungarian genotypes to fire blight collected from the English National Fruit Collection (Brogdale, Faversham) is presented.
13 old Hungarian apple cultivars in 2002, and 38 genotypes in 2005 have been evaluated. We used `Idared' and 'Jonathan M41' as susceptible controls and 'Liberty' and 'Remo' as resistant ones. Shoots of two-year-old potted plants were inoculated with a mixture of virulent E. amylovora isolates (Ea2, Ea60, Ea67) at a concentration of 5 x 108 cells/ml. Resistance of apple cultivars was evaluated weekly, four times after inoculation by disease severity of symptoms. Numbers of bacterial colonies in 1 cm length shoot were determined in the fourth week after infection.
8 cultivars in 2002 and 9 cultivars in 2005 displayed notable resistance to fire blight based on one-year data. Based on the coincident data of both years, out of the cultivars collected also from Carpathia ‘Pónyik', and `Sikulai' were found to be resistant and gene sources additional old Hungarian valuable apple genotypes could be selected: `Szabadkai szercsika' and `Tordai piros !davit'. The cultivar `Szemes alma' originated from Visk has proved to be recurrently resistant.
The number of bacterial cells in shoots of the investigated cultivars correlated with the severity of symptoms. With this method, which was introduced by us earlier, we can screen cultivars displaying weak visible symptoms, which cannot be proposed as a source of resistance because of their latent infection.
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Evaluation of crop yield and fruit quality in organic apple production
7-10.Views:224In this study, crop yield and fruit quality parameters (soluble solid concentration, sugar, total acid, and vitamin C content) of 15 apple cultivars including old, resistant and currently grown cultivars. The highest fruit yield among all 15 cultivars was obtained on CV. Jonagold with 15.5 kg/tree, while the lowest yield was measured on the resistant cultivar Reanda with 8.1 kg/tree. There were no significant differences among the cultivars in fruit diameter ranging from 70 mm in the case of cv. Húsvéti rozmaring to 82 mm for cv. Mutsu. Values of soluble solids concentration of the cultivars varied between 15.5% for cv. Téli Banán and 19.2% for cv. Renora. Sugar content values showed a similar tendency to soluble solids content. The highest and lowest total sugar content was observed on cvs. Jonagold and Renora and cv. Retina with 17% and 12.4%, respectively. Total acid content values ranged between 0.18% and 0.53% for cvs. Jonagold and Remo, respectively. Values of vitamin C content for the 15 apple cultivars varied between 2 mg% and 4 mg% for cv. Retina and cv. Mutsu, respectively.
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Anatomical relations of the leaves in strawberry
81-84.Views:225In the present study histology of the leaves of strawberry (Fragaria ananassa Duch.) variety Elsanta was the objective, which has been performed with the beginning of seedling stage, cotyledons, primary leaves and later true leaves, first cataphyll of the runner shoot as well as the bracteoles of the inflorescence. Structures of the leaf blade, the upper and lower epidermis, the petiole have been also observed. The leaf blade of cotyledons already contains a typical palisade as well as spongy parenchyma tissues, i.e. being bifacial showing a structure similar to that of the true leaf. However, the petiole displays differences from the true leaf. There are a narrow (4-5 layer) primary cortex and a tiny central cylinder. Primary leaves bear already hairs on the adaxial surface and the transporting tissue-bundles are recognised in cross sections having a "V" shape. The first true leaf composed by three leaflets is of a simple structure showing characters reminding of cotyledons and primary leaves. Leaves of intermediate size continue to grow, whereas their inner anatomy changes dramatically. In the central region of the leaflets, near to the main vein, a second palisade parenchyma appears, further on, transporting tissue bundles are branching in the petiole. Collenchyma tissues enhance the stiffness and elasticity of the petiole. Older true leaves develop thick collenchyma tissues around the transporting bundles being represented by increasing numbers. The doubled palisade parenchyma layers of the leaf blades are generally observed. The cataphylls of the runners have a more simple structure, their mesophyll is homogenous, no palisade parenchyma appears. It is evident that leaves grown at successive developmental stages are different not only in their morphological but also anatomical structure. There is a gradual change according to the developmental stage of the leaves.
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Cultivars, marketing and integrated Production of apples in the Czech Republic
87-92.Views:131Development in apple production in the Czech Republic has been adversely effected during a few recent years by escape of capital investment from the agrifood industry (due to privatisation, restitution and transformation). On the other way round the competition on the domestic market is much higher than it was before because of unlimited import of subtropical and tropical fruit and some import of traditional fruit species as well. Therefore fruit growers are very much concerned in any possible means (which are not economically feasible) to be more competitive. One of the most common approach is the use of new cultivars bred in the country which are resistant or tolerant to diseases and offer better quality both for fresh market and processing. Another way for increasing competition ability for fruit growers is the join and mastering of integrated production which also considerably improve the quality of fruit as far as aspects of health are meant.
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Evaluation of the quality of Sorbus fruits belonging to different species
37-41.Views:171The interest in wild growing fruits was increased considerably by the pharmaceutical industry, the cosmetics as well as by the food industry. (Stefanovits-Bányai et al., 2004). Elderberry (Sambucus nigra L), sand thorn (Hippophae rhamnoides L.), cornet (Cornus mas L.), dog rose (Rosa canina L. bearing hips) and the Sorbus species (Sorhus ssp.) have been well known medicinal and/or ornamental plants since long. Recently, precious substances have been detected in their fruits, which are indispensable in healthy foods. Several species and micro-species of the genus Sorbus are components of the native flora of Hungary, and the fruit of some of them have been consumed traditionally, however, they are preferably considered as ornamentals. The nursery of Alsótekeres (Balatonvilágos) maintained some 16 clones of Sorbus species, which are mainly apomictic "micro species" of. the collection. In 2003, a comprehensive analysis of sorb fruits born on apomictic micro species was initiated in order to find those, which will be suitable to establish plantations. It turned out that considerable differences exist between the fruits of individual taxa, however, it is largely influenced by seasonal effects. According to physical measurements, a scale of mean fruit masses could be established. As for chemical ingredients of the fruits, those are of special interest, which are involved mainly in anti-oxidant activities of the organisms (calcium, potash, phosphorus, copper, magnesium).
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Characteristics of fruit producing enterprises according to the data of farms taking part in the test farm system
41-45.Views:132Fruit farming plays an important role within the Hungarian agriculture. The climatic conditions of the country make it possible to produce 20 temperate-zone fruit species, 14-15 of which are economically significant. The weight of the sector is high relative to the immobilised land, it is important in the field of employment and holding of rural population.
I examined the enterprise form, production size, revenues and profit of farms dealing with fruit production relying on the data of the agricultural test farm system of 1999. The proportion of croppers and entrepreneurs is significant among fruit producers. Their revenue realising ability is low, which depends on the production size too. But the polarisation of these farmers has started and a new level is being formed that is considerable from the viewpoint of value production.
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Incidence of postharvest decays on cultivars of pear, apricot, sour cherry and peach under two storage conditions
63-65.Views:347In this two-year study, postharvest decays of pear, apricot, sour cherry and peach cultivars under two storage methods (TC and CA) were determined after four monthes storage periods; and then causal agents of postharvest decays of two pear cultvars were idenfified under traditional cold storage conditions. Results showed that postharvest decay was lower under controlled atmosphere compared to traditional cold one. Decay was lower on pear and the largest deacy occured on peach and apricot cultivars. Cultivars of fruit species also showed differences in incidence of fruit decays. Incidence of decays was independent on year effect. Under controlled atmosphere, postharvest decay ranged between 0 an 8% for pear, and between 5 and 12% for apricot, and between 6 and 11% for sour cherry, and between 5 and 15% for peach. Under traditional cold storage, postharvest decay ranged between 16 an 21% for pear, and between 15 and 39% for apricot, and between 10 and 22% for sour cherry, and between 19 and 33% for peach. Incidence of pear fruit damage ranged between 7.5 and 12.3%. Most damage started from injured fruit or wounded fruit. Five types of damage occurred ont he pear fruits in both years: Penicillium spp., Monilinia spp., Chondrostereum spp., other pathogens and mechanical injury. The most common damage was caused by Penicillium spp., Monilina spp. and Chondrostereum spp. On both pear cultivars in both years.
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Micro area based spatial distribution of apple scab in an organic apple orchard
21-23.Views:268In this study, the objective was to report a two-year investigation on micro area based spatial distribution of apple scab in an organic apple orchard. Results showed that number of symptomatic plant part ranged between 587 and 623 on leaf and between 46 and 78 on fruit for an individual tree. Number of asymptomatic plant part ranged between 1034 and 1321 on leaf and between 119 and 193 on fruit. Disease incidence ranged between 35 and 40% on leaf and between 27 and 33% on fruit. Disease aggregation index ranged between 0.115 and 0.298 on leaf and between 0.117 and 0.221 on fruit. Three of the four trees showed significant within canopy aggregation of disease for leaf apple scab symptoms in both years. For fruit apple scab, two of the four trees showed significant random patterns in both years.
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Identification of ripening-related genes in strawberry fruit by cDNA-AFLP
33-41.Views:165An RNA fingerprinting study of strawberry receptacle and achene tissue was performed to identify candidate genes involved in fruit ripening. Quantitative cDNA-AFLP was used to detect differential gene expression in green, white, pink and red stages of fruit ripening. Based on hierarchical average linkage clustering the differentially expressed genes formed three major groups, genes expressed only in green receptacle, genes expressed mainly in white, pink and red receptacle, and in achene. 130 transcript-derived fragments (TDFs) were isolated and sequenced. Most TDFs did not show any homology to sequences with known functions, others were homologous to genes involved in oxidative stress response, signal transduction, regulation of development and cell-wall metabolism. Novel genes, so far not associated with strawberry ripening and ripening in general, were identified, such as genes encoding a bHLH protein, putative nitrilase-related protein, putative HD-zip protein. The differential pattern of gene expression draws the attention to the significance of ripening induced-or repressed promoters in strawberry fruit, whose isolation and characterization can be useful tool for functional genomics. For this purpose nine cDNA-AFLP fragments related either to ontogeny or senescing were completed with 5'UTR aiming at more precise annotation and future promoter isolation. Although tens of potentially important transcriptome changes were identified, the function of many ripening induced genes remain unknown.
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Studies on the drought responses of apple trees (Malus domestica Borkh.) grafted on different rootstocks
29-36.Views:598The morphological and chemical changes in the leaves of eight apple varieties grafted on M4, M26 and MM 106 rootstocks were examined during fruit development in non-irrigated plantation. The aim of the experiment was to examine the defensive mechanisms in apple trees under the mild and serious dryness occurring during fruit development. The content of a relative chlorophyll (SPA D value) of the apple leaves on eastern side of the trees was lower than western and southern sides under drought occurring du ring fruit devclop111ent Under sustained drought from first of July to August the SPAD value, the weight of leaves were larger and the stomata density was significantly larger than in the previous periods. There was a close positive significant correlations bet ween SPAD and stoma density both in the group with less sensitive to drought (r=0,8429) and in the large water demanded group (r=0,9209) equally. The rate of increase in SPAD values and the stoma density was slower in the group with drought tolerant, than in the group required good water supply. The varieties being sensitive to water deficite such as Akane. Pink Lady and Red Rome van Well have a l ready responded intensively to short time of drought by the increasing of carbohydrate and antioxidants product ions. At 42 days of sustained drought as soon as the level of carbohydrate in the leaves decreased, the antioxidant s contents of the leaves rised suddenly in the apple varieties with moderate water requirement s as Greensleeves and ldared. Gala apple variety seemed to be able to defend the drought for longer time because there was no change in relatively high level of carbohydrates and antioxidants of their leaves under severe drought during fruit development.
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Inter-incompatibility of self- incompatible apricots and their varietal properties
79-81.Views:342There are four apricot varieties grown in Hungary derived from local selections known to bear fruits of giant (60 - 100 g) size: Ceglédi óriás, Nagykőrösi óriás, Szegedi mammut and Ligeti óriás. Being morphologically similar, they seem to be closely related to each other. The detailed study of the morphology (of leaves and fruits) and phenology (of blooming and ripening dates) as well as the fertility relations was aimed to find out the degree of kinship between the varieties in question.
It was stated that the value of morphological traits is variable from the taxonomic point of view. The most important signs of common origin were the time of blooming and the leaf size. Less valuable are the date of m:iurity and the size of fruit because of their variability. In the literature Satin') & Nyeki (1991) published the first proof of inter-incompatible relation between apricot varieties. This should be considered as an argument of close genetic relation between those "giant" varieties of apricots.
The first three varieties. Ceglédi óriás, Nagykőrösi óriás and Szegedi mammut are closer related in blooming and ripening date, as well as in size of fruit to each other than the variety Ligeti óriás.