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Yield and fruit quality response to foliar application of biostimulants in an apple orchard
17-23.Views:424Nutrient supply plays an important role in fruit production technology. Among the methods of nutrient management, the application of foliar fertilization has become an essential tool to harmonize the vegetative and generative performance of fruit trees. This study was conducted to determine the effect of four foliar fertilizers (Bistep, brown juice, Trichoderma harzianum, Clonostachys rosea) on yield and fruit quality in an apple orchard with the cultivar ‘Pinova’, at the University of Debrecen in Hungary. Trees were trained to a slender spindle canopy with a spacing of 4 × 1 m. Treatments were applied five times during different phenological phases in 2021 and 2022. Based on our results, biostimulants had a positive effect on fruit yield and fruit quality, but extreme weather events also influenced the data. In 2021, the effect of the treatments on yield data could not be observed (10.1–13.5 kg/tree; 0.16–0.24 kg/cm²). However, in 2022, plants sprayed with Bistep, T. harzianum, and C. rosea reached 28.7–31.2 kg/tree (0.33–0.46 kg/cm²), while control trees produced only 19.8 kg/tree (0.20 kg/cm²). Fruit size development improved with an increase of 2–6 mm over the two years. Among the treatments, Bistep was able to enhance fruit surface coloration to a greater extent in 2021, as red skin color reached 44% for this foliar fertilizer, while control trees presented only 27%.
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Effects of DMI and strobilurin fungicide combinations on scab and powdery mildew incidence in apple production: a preliminary study
37-39.Views:574The aim of our study was to evaulate the effectiveness of four DMI and strobilurion fungicide combinations in a season-long disease management programme against apple scab and powdery mildew in two integrated apple orchards on cultivar Jonagold. The four spray programmes were: i) standard, ii) DMI dominant iii) strobilurin dominant, and iv) DMI and strobilurin dominant. Apple scab incidence as generally high in both orchards in the standard fungicide treatment plots ranged between 21.8 and 26.4%. Leaf scab incidence was higher in all treatments compared to fruit incidence. Scab incidence was generally higher at Mándok compared to Ófehértó. In both locations the lowest scab incidence was assessed in DMI dominant treatment ranged between 5 to 10.7%, which was not signifi cantly different from the DMI and strobilurin dominant treatment. Powdery mildew incidence was generally low in both orchards in all fungicide treatments ranged between 0.002 and 0.5%. Although there were no signifi cant differences among treatments, the lowest powdery mildew incidence was assessed in the DMI and strobilurin dominant treatment in Mándok and in the strobilurin dominant treatment in Ófehértó.
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Molecular characterization of apricot (Prunus armeniaca L.) cultivars using cross species SSR amplification with peach primers
53-57.Views:337Apricot takes an important place in Hungarian fruit production. Considering morphological characteristics of apricots it was concluded that the genetics background of European cultivars is very limited. Molecular markers and their use for genotyping have revolutionized the identification of cultivars. In a classic apricot breeding program, it is important to be able to establish unique DNA profiles of selections to identify them unambiguously and to determine their genetic relationship. Presently SSR is far the most frequently performed technique for genetic diversity studies. In this study there were used peach and apricot primer pairs from four different sources in order to examine microsatellite polymorphism among cultivars and investigate relationships among them. The possibility of cross species amplification among different Prunus species using SSR primers allowed us to use primers developed in peach to study genetic diversity in apricot. In this work, 90% of the primers used were able to amplify SSRs in apricot and more than half of them were polymorphic. With the 10 primer pairs utilized were proven to be sufficient to set unique fingerprint for several cultivars studied. The obtained dendrogram classified of the 45 cultivars included in this study into two major groups and several subgroups.
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The effect of rootstock on the tree size of apricot cultivars
57-58.Views:212The apricot is propagated on several kinds of rootstocks in Hungary. The main aspects of selecting rootstocks are as follows: adaptability to environmental circumstances, primarily soil conditions, ensuring the tree size that complies with the cultivation method, and compatibility with the grafted cultivar. At advanced, intensive orchards rootstocks ensuring smaller tree size are privileged. For the establishment of the appropriate cultivation system, it is important to be aware of the expected growing vigour and tree size of certain cultivarrootstock combinations when the orchard is designed. In the course of our experiment the size of 15-year-old trees of 4 apricot cultivars were examined on several rootstocks at an orchard in Siófok. On the basis of the data measured for each cultivar-rootstock combination, it can be stated that trees on wild apricot (P. armeniaca) rootstocks are the largest in size. Trees on prune (P. domestica) rootstock have 10-15% smaller crown volume than the previous combination. Trees on bullace (P. insititia) rootstock have the smallest tree size and their crown volume is 30-50% smaller than that of the trees on P. armeniaca rootstock. Thus, the application of prune and bullace rootstocks is beneficial at intensive apricot orchards as the size of trees can be reduced by their usage. However, their compatibility with the cultivars and their adaptability to the ecological conditions of the production site have to be tested before applying them widely. In the course of our research incompatibility was not experienced for any of the cultivar-rootstock combinations examined. Nevertheless, the drought tolerance of the rootstocks examined showed significant differences. Trees on P. domestica or P. insititia rootstock requires more water than those on P. armeniaca rootstock, therefore, they have to be irrigated.
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The uses of wolfberry (Lycium barbarum L.) as a fruit in an international breadth of view
7-13.Views:446Lycium barbarum is known exclusively as an ornamental plant in Hungary, and is planted so, as popular belief deem it a toxic plant. The plant’s fruit receives great respect in countries abroad, thus, due to its favourable content values the Lycium has achieved the title of ‘biological gold mine’. The last couple of years has seen the import of Lycium shrubs and its corresponding products, dried goods or in the form of various processed products which have been marketed and sold at extreme prices (under name of Goji, Wolfberry, Lifeberry). Our goal was to examine the similarities of the content values of wolfberry found in Hungary and those cultivated abroad. Along with Miklós Józsa the domestic Lycium population was surveyed based on foreign examples, between the years 2009 and 2011. Those defined sweet and largefruited were selected for further investigations to be set into a clone repository. This clone repository– which contains 67 different clones from a number of regions of Hungary – was established in the nursery of Dr. Miklós Józsa, located in the city of Szombathely. The phenological and morphological characteristics and the fruit ripening and quality indicators of plants in the clone repository were investigated. Six ‘best’ clones – selected based on flavour, disease-resistance and vegetative characteristics (plant size, fruit set, yield and fruit size) were analysed based on their content values. The control plant was a cultivar imported by a delivery service, found also in growing. In addition to the results of the selection, the results of the content values of the six selected ‘best’ clones (total soluble sugar content, glucose-fructose ratio, carotene content, FRAP value) is documented in this paper. Further, based on the resulting information the possibilities of the fruit’s utilization are suggested. Significant differences were measured in the vegetative characteristics of the clones (plant size, fruit set, yield and fruit size) and of those of
its inner content values. The resulting properties are considerable in regards of the plant’s introduction into cultivation and also utilization. Based on growing characteristics, more favourable clones were selected than the foreign varieties already in growing. Those clones selected by us have had similar or better content values than foreign breeds. The investigation of these content values is still in progress. -
Specialities of the vegetation start and level of primary fruit set affect fruit quality
17-22.Views:511Thinning is a h ighly crucial point of the apple production technology. According to results of numerous studies the earliest thinning is deemed to have the best amending effects. There can be considerable difference between trees of the same cul tivar and age in a plantation in respect to their flowering, in the numbers of fruits set and also in their canopy volume. Thus it can be crucial -just l ike in the case of pruning- to establish a fruit thinni ng su i ted for specif ic characteristics of actual trees. This experiment was established to examine how does primary fruit set (fruit load before thinning) and further on specific (fruit/TCS cm2) and absolute (fruit/tree) fruit-load of the trees affect quality attri butes at harvest. Our experiment was establ ished in a plantation on medium-tight loamy soil in north-east of Hungary. Harvest date was determined w ith the joint observation of the calendar date, starch-index, flesh firmness, background colour and fruit weight. Three fruit-load levels were established based on local experience and on data of several years, I Ot/ha lower and higher besides the advised optimum yield in the same orchard with slender-spindle shaped 'Gala must' cultivar standing on M9 rootstock in 1m x 3,8 m spacing. In the establishment of the 15, 25 and 35t/ha fruit-load levels on 20-20 apple trees total number of fruits set was counted at each tree. After this number of apples due to be removed was defined using an objective index on the basis of trunk cross sections (fruit/TCScm2) (Lafer, 1999). The following attributes were measured: weight (g), flesh firmness (lb/cm2) total soluble solid content (Brix %) and total titrate-able acid content (g/J).From the data on sugar and acid content quality index (Pomona value) was determined (Thialult, 1970). We could ascertain, that in an orchard, of the same aged but in concern to trunk cross sections somewhat different trees besides the specific index (apple/TCS cm2 the absolute fruit load (fruit/tree) can also be an important data, that has considerable effect on the internal quality. Secondly we could observe, that higher level of fruit load before thinning (primary fruit set) negatively affects quality index of the apples irrespective of the specific fruit load level (fruit/cm2 TCS) set later. Results underlines necessity of the earliest chemical thinn ing.
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Postharvest methyl jasmonic acid and hot water can reduce the internal breakdown and quality loss of apricot fruit at shelf life
31-34.Views:337The aim of this study was to investigate the postharvest effect of methyl jasmonic acid (MJ) and hot water on internal break-down and quality loss of apricot fruit under shelf life conditions. Cultivar Flavor cot apricot fruit were used to treat with water as control treatment, with 0.2 mmol/L MJ and with hot water 35 oC for 5 min. Fruit were stored at room temperature and were examined every 2 days for internal break-down and quality loss. Results showed that treated fruits with MJ and hot water showed the lowest weight loss and the highest firmness during all assessment times. Control fruits showed losing of customer acceptance from the day 2 of shelf life and then decreased dramatically to approximately loss all the acceptance at day 8. The SSC showed sever reduction in untreated fruit after day 6 at shelf life. Total phenol content reduced and polyphenol oxidase (PPO) increased in all assessment times for all treatments. Meanwhile MJ showed the best values for phenol content and lowest PPO activity. The results supported the idea of using some elicitors like methyl jasmonic and hot water treatments to enhance shelf life of apricot fruit.
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Possibilities of blossom and twig blight management in organic stone fruit production
103-105.Views:431In 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).
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Impact of potassium fertilizers with different active ingredients and dosages on potato yield in experiments in the Nyírség region
71-74.Views:232A five-year experiment was carried out in the Nyírség on its characteristic soil type, brown forest soil to investigate the impact of three types of potassium fertilizers (potassium chloride, potassium sulfate and Patentkali) in three different dosages (80, 160, 240 kg/ha K20), under non-irrigated conditions applying the same dosages of N, P in all treatments (the applied amount was different between years) in 10 treatments including the control on 50 m2-parcels with 3 or 4 replicates. The test plant was cultivar Desiree, Kondor, Agria and Pannonia in 1998 and 2000, 2001, 2002 and 2003, respectively. The obtained yields were analyzed by an analysis of variance. Based on the five-year results, the highest yields on the acidic sandy and sandy loam soils were obtained in the treatments with 530-800 kg/ha Patentkali containing 30% of K and 10% of magnesium active ingredients in addition to the same amounts of N and P applications. The dosage of 530 kg/ha Patentkali contains 160 kg/ha K+ 53 kg/ha Mg active ingredients, while the dosage of 800 kg/ha Patentkali contains 240 kg/ha K+ 80 kg/ha Mg active ingredients. It can be concluded that the potassium chloride fertilizer (KCI) was the least effective as regards yields and Patentkali proved to be the most effective fertilizer, it had higher yields than even those of potassium sulfate, the difference in the 160 kg/ha treatments was 17.7%, which was a significant difference. Based on the results of the multi-year experiment, we recommend to apply 530 kg/ha Patentkali fertilizer (160 kg/ha K+ 53 kg/ha Mg active ingredients) for the fertilization in potato under non-irrigated conditions on the acidic sandy and sandy loam forest soils of the Nyírség, which proved to be the most effective treatment and with which we could obtain 30 t/ha yield in the average of the years (with the simultaneous application of N and P).
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Application of DNA markers for detection of scab resistant apple cultivars and selections
59-63.Views:194A DNA marker-based study was undertaken to identify the occurrence of major scab resistance genes in some apple cultivars and selections of importance for apple breeding. Unfortunately none of the RAPD-based markers previously reported to detect the Va, Vb, Vr and Vx genes produced unambiguous results. By contrast, the CAPS marker MI8 produced the expected three bands in all cultivars and selections already known or suspected to have the Vf gene, as well as in the Russian cultivar 'Antonovka Polotora Funtovaja' suspected to have Va resistance which however may be allelic to Vf. Vf-carrying selections and newly named cultivars 'Frida' and 'Fredrik' are grown successfully in Sweden without fungicides, suggesting that the Vr resistance breaking scab races 6 and 7 have not yet become a problem. The SCAR marker B12 detected the Vm gene in 'Prairifire', 'Rouville', clones 'OR45T132' and 'OR48T70', and selection '16-36-193'. The SSR locus 0102b10 detected one band at 118 by in 'Reka'. This is presumed to be identical to the Vr gene marker previously reported.
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The effect of cluster thinning, cluster tipping, cluster shredding and defoliation at the flowering on the vegetative and generative vine performance from Kékfrankos Cv.
63-68.Views:414The cluster thinning is a method of the yield regulation.With the removal one part of the clusters, the yield pro leaf area will be lower, hereby the grape and wine quality will be improved. The regulation of the yield can lead to further advantages: the ratio of the vegetative and generative performance of the vines will improve, the condition of the plants will better, the number of the physiological diseases can be reduced and the growth of the shoots and roots can be promoted. The grape growers make the cluster thinning almost exclusive by creating one cluster shoots. Usually the upper clusters are removed, because the sugar content of these second or third clusters will be lower. The cluster thinning is an easy task, can be done without special skills. It is an effective method improving wine quality, but its use can lead to other problems. The grapes try to compensate the removed clusters. Therefore the clusters will be bigger and thicker, but more sensitive to bunch rot. Moreover the treatment is expensive, because it needs manual work. It is worth to get acquainted and try the new yield regulation methods, which can help to avoid the occurring problems. Our aim is to show the results of our experiment, which was carried out in Eger, examining the red grape cultivar Kékfrankos. During our 4 years long experiment we compared the effects of cluster thinning, cluster shredding, cluster tipping and defoliation at the flowering, on the vegetative and generative vine performance.
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Effect of different flower thinning techniques on annual fluctuation of macro and micronutrients in sweet cherries
87-90.Views:640The seasonal dynamic of macro- and micronutrients uptake of a sweet cherry cultivar cv. 'Katalin' (Prunus avium L.) was studied according to apply different flower thinning techniques. Beside control treatment, three thinning treatments were performed: (I) thinning for I flower/inflorescence, (2) thinning for 2 flower/inflorescence, (3) thinning for 3 flower/inflorescence. Soil examination was carried out to establish the growing conditions of orchard site. Moreover, for studying the temporal dynamic of nutrient uptake plant analytical examination was performed four times per year based on leaf collecting according to the phenological phases. It was found that the macro- and micronutrients contents of leaves were showed significant differences between treatments before ripening, at ripening and after ripening stage. It was found that thinning has influence on mineral composition of leaf. Flower removal unbalanced the equilibrium of generative and vegetative processes. The applied manual flower thinning treatment resulted improving vegetative processes like nutrient uptake and storage.
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Model experiments for establishment of in vitro culture by micrografting in apple
47-49.Views:399Micrografting was used in our experiments for establishment of in vitro culture from one rootstock (`JTE-F') and three scion cultivars (`Remo', 'Rewena' and `Reanda') of apple. Shoot tips of these cultivars were harvested from field and grafted onto in vitro rootstock cultivars. Their survival and development were studied. 42-93% of shoot tips survived and developed further depending on cultivar. Impermanent browning of sticking agar-agar could be observed in 21-25% of the micrografts depending on cultivars but discolouration of agar-agar ceased within one week and did not cause any death of shoot tips. We used micrografting successfully for establishment of in vitro culture from cultivars, from which earlier with conventional methods the culture establishment was not possible because of hard tissue browning. However, further studies are necessary to ensure the survival and development of shoots after removing them from micrografts.
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Nectar production of quince (Cydonia oblonga Mill.) cultivars
87-94.Views:1005Nectar production of six quince cultivars were measured during three consecutive years. The nectar production of quince can be regarded to be small compared to other temperate zone fruit tree species since quince flowers contained 1.07 ± 0.06 mg of nectar in average. The extreme values, however, ranged between 0.1 and 7.3 mg/flower and this indicated that the nectar production was highly variable. The distribution of the nectar production was definitely skew because low values were definitely much more frequent than the highest ones. Our findings do not corroborate the earlier statements on the high sugar concentration of quince nectar. We found some 21-27% sugar in average, only. The normal distribution of the sugar concentration also indicates that the typical sugar concentration may be between 20-30%. Accordingly, the sugar concentration of quince nectar is rather low compared to other temperate zone fruit tree species (except pear). There was a significant negative correlation between the amount of nectar and its sugar concentration in quince flowers in all of the three years of the study (r= -0.51, n=37, p<0.02 in 1996, r= -0.57, n=28, p<0.1 in 1997, r= -0.35, n=9 I, p<0.001 in 1998). No definite difference was established between the nectar production of quince cultivars. Nevertheless, one cultivar tended to produce less and two other ones produced somewhat more nectar in average than the rest of the 6 cvs investigated but the extreme values of nectar production of cultivars overlapped in most cages.
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Goals and results in improvement of biological background of medicinal plant production
20-27.Views:316The choice of varieties among medicinal plant species is relatively small, compared to other horticultural crops. In Hungary, only poppy (Papaver somniferum) and mustard (Sinapis alba) have several cultivars. Recognising the problem, in the recent years breeding activity has been intensified all over the world, in spite of financial, technical and legal difficulties. The article reports on the results of breeding at the Department of Medicinal and Aromatic Plants of the Szent István University, 11 varieties of which has been officially registered till 2000. Main goals of genetic improvement are: increasing of the production capacity of utilised plant organs, enhancement of active material accumulation capacity, improvement of sensory quality and technological properties. The most often applied methods are selection, and recently, cross breeding, the results of which can be measured on new materials of caraway (Carum carvi), hyssop (Hyssopus officinalis), marjoram (Majorana hortensis), poppy (Papaver somniferum), etc. Efficacy of breeding work is established by additional, regular research on the genetics, physiology, floral and reproductive biology, chemosyndromes of medicinal plant species.
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Epiphytic microbiota of apple in integrated and organic growing
85-89.Views:623The surface microbial contamination is of great interest in case of fruits, since they are they potential sources of spoilage or foodborne diseases. The aim of this work was to compare the epiphytic microbiota of food safety concern of different apple cultivars as a function of cultivation methods (organic versus integrated), production year and place. Investigating 47 samples it was found that the average microbial contamination of the apple surfaces was within a certain range,, practically independent of cultivar, growing area and year. The frequency distribution of the surface bacterial, mould and yeast counts did not show significant differences between growing technologies or varieties. The principal component analysis the samples ranked the apple samples into seven groups on the basis of their microbial contamination level, and the discriminant analysis proved the goodness of grouping. The grouping was independent from cultivars and growing methods. No foodborne pathogen Salmonella spp. and Listeria spp. were found on the surfaces of apples.
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Influence of strawberry and raspberry consumption on the antioxidant status of human body
109-113.Views:365Several parameters influencing the antioxidant capacity were measured in our experiments to compare strawberry and raspberry cultivars. The analysed cultivars were: 'Honeoye', 'Elsanta', 'Onebor (strawberries) and 'Glen Ample', Fertődi zamatos', 'Mailing Expoit' (raspberries). Besides the determination of dry matter content the content of glucose, fructose, total phenol and anthocyanine, the reducing power, H-donating activity and total scavenger capacity were measured as well as the compound of mineral nutrients. Among the species and the cultivars, differences were obtained. These results call the attention to the features of cultivars and to count on the antioxidant-capacity describing values in case of consuming these fruits. In early spring and summer the consumption of strawberry and raspberry has a beneficial contribution to the antioxidant status of our body. In this respect these are more valuable than the year-long consumable apple. Accordingly, our measurements showed higher amount of sucrose, phenolic compounds and anthocyanine in raspberries, but strawberries contained more glucose and fructose and had stronger H-donating activity. It is worth to keep in mind that e.g. which cultivar contains more of certain compounds because of the strictly determined allowable dose in some diseases (e.g. diabetes).
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Biochemical changes in pear (Pyrus communis L. depending on different phases of the dormancy
47-50.Views:321Pear cultivars of variable frost tolerance were tested as for frost injuries suffered as a consequence of artificial freezing temperatures during the endodormancy as well as the ecodormancy. Damages were registered according to a visually defined scale, then peroxidase and polyphenol-oxidase activity was checked in buds, spurs and limbs. According to our results, 'Packham's Triumph' was the most frost tolerant cultivar. Regarding enzyme activity of both enzymes, the performance of cultivars displaying different susceptibility was also different in spurs as well as in buds. Results referring to the endodormancy were especially instructive. During the ecodormancy, data obtained at the same time indicated the differences existing between the developmental stages of dormancy in the respective cultivars.
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Response of sour cherry cultivar `Érdi jubileum' fruits to modified atmosphere packaging after ethephon spraying
81-85.Views:280Sour cherries are not adapted to long storage. The largest percentage of sour cherries reaches the consumer either directly or indirectly through the tin can or the frozen pack. Different concentrations of ethephon usually are used commercially to facilitate harvesting sour cherry fruits that this hormone influences on fruit quality. The objective of this study was effect of ethephon preharvest application on sour cherry fruits quality during storage period at modified atmosphere packaging was investigated. Modified atmosphere packaging used with 10, 15 and 75 percent for 02, CO, and N2 respectively that those held at 0 °C. This gas compounds synchronous to 0 °C temperature caused to increase shelf life postharvest of fruits. Fruit samples were evaluated at harvest date and after 6 weeks in storage. Skin fruit colour, pH, total soluble solids, titrateable acidity, sugar/acid ratio, firmness were monitored. Ethephon concentration influenced on total soluble solid, titrateable acidity, sugar/acid ratio and L* value. In more case, 225 ppm ethephon's concentration has no observable different to control samples. Thus, the best ethephon's concentration was 225 ppm ethephon's concentration.
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Anatomical study of the leaves and petioles of scab resistant and susceptible apple cultivars
53-57.Views:301Anatomic studies have been performed on the leaf blade, petiole and annual shoot on six apple cultivars by means of scanning electron as well as light microscope. Four of the cultivars examined are resistant to scab (Florina, Freedom, MR-10, MR-11), whereas two of them are susceptible (Jonathan and Idared). Preliminary results suggest that differences in the width of cross sections of leaf blades, in hairyness, in the shape and size of epidermal cells, moreover, in the cross sections of petioles and shoots are considerable. Some of the anatomical properties seem to be correlated with scab resistance or susceptility of the respective cultivars. Therefore, further studies extending to other cultivars may corroborate our claims to find causal relations between anatomical traits of the leaves and disease, especially scab resistance of apple cultivars.
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Concentration of ‘Oblachinska’ sour cherry juice using osmotic distillation
31-34.Views:958Sour cherry is one of the most famous and characteristic Hungarian fruit what is also commonly used in food production as a colour additive. The sour cherry cultivar, ‘Oblachinska’ was shown to be a rich source of antioxidant compounds, including mainly anthocyanins. Valuable compounds in fruit juice – vitamins, polyphyenols etc. –are heat-sensitive molecules, which should be taken into account during the process of concentration to prevent degradation. Osmotic distillation seems a suitable option to product high quality sour cherry juice because this process does not require high temperature or pressure. Raw juice with approximately 15°Brix was used for the experiment and tried to concentrate up to 60° Brix where the water activity low enough to inhibit the microbiological deterioration. Before and after the process, TPC (total phenolic compounds) and FRAP (ferric reducing antioxidant power) was measured using spectrophotometric methods to determine the effect of the osmotic distillation. Our results point out that osmotic distillation is a promising method to concentrate sour cherry juice and prevent the loss of valuable compounds.
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Severely pollen-limited fruit set in a pear (Pyrus communis) orchard revealed by yield assessments and DNA-based paternity assignment of seedlings
67-74.Views:295In commercial fruit tree orchards, consistently high yields are necessary for a durable economy. The Swedish pear cultivar 'Carola' has been noted for low setting in some orchards, possibly due to insufficient pollination. In this study, fruit set was evaluated in a research orchard where `Carola' had been planted together with four potential pollinators. Total yield and number of fruits was noted during three and four years, respectively. In 2003, seeds were germinated from the harvested `Carola' fruits, and the paternity of three seedlings from 50 trees was determined with RAPD analysis. 'Clapp's Favourite' had sired 39.6% of the seedlings, closely followed by `Seigneur d'Esperen' (30.7%) and 'Clara Frijs' (26.7%) whereas 'Skanskt sockerparon' only sired 1.1% of the seedlings. The remaining 2.3% appeared to have been derived by selfing. Pollen-limited seed set was indicated at surprisingly short distances; accumulated number of fruits on the `Carola' trees was significantly higher when separated by only 2 m from one of the two most efficient pollinators, 'Clapp's Favourite' or 'Seigneur d'Esperen‘, compared to trees 4—l0 in away in the same row. Number of viable seeds per fruit was also higher in fruits from trees immediately adjacent to the pollinators, suggesting an effect of improved pollination success. The importance of very short inter-cultivar distances for efficient pollen transfer became even more clear when comparisons involved the true pollination distances as determined by RAPD; the accumulated yields decreased linearly from 55 kg at a 2 in distance to only 17 kg at 13 m.
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Effect of intensity of bee visitation and the foraging behaviour of honeybees on the fruit set and yield of apple (Malus domestica Borkh.)
31-39.Views:275Based on the results of our experiments, both the relative and the effective intensity of bee visitation were rather different depending on the cultivars as well as the time of the day. While it varied between relatively extreme values (40-80%) in the morning for the varieties examined, there were much smaller differences between the intensity of bee visitation at the afternoon, because the relative bee visitation attained 70-90% at each cultivar. These results showed that the differences arising from intensity of bee visitation of different cultivars should be taken into consideration more carefully in the morning in orchard planning and in estimating the number of honeybee colonies required.
The results showed that the greatest percentage of fruit set and the highest number of viable seeds per fruit were measured on branches of those cultivars that were most frequently visited by pure pollen gatherer bees as well as by bees collecting both nectar and pollen (mixed behaviour). The effect of pure pollen gatherers and of bees with mixed behaviour was highly significant from the statistical point of view on the fruit set and the number of viable seeds per fruit.
Those bees that were sucking nectar only from apple flowers did not proved to be effective pollinators at all. Relationship between their number and the fruit set as well as the number of viable seed per fruit were not significant because the coefficient of correlation was close to nil.
The ratio of side worker nectar gatherers was negatively correlated with the fruit set and the seed content of fruits of apple cultivars examined at both of our experimental sites, at Mosonmagyaróvár and Feketeerdő as well. The presence of side worker nectar gatherers resulted in higher decrease of fruit set and seed content of fruits at Feketeerd6 than at Mosonmagyaróvár, especially in the morning.
The effect of flower visiting intensity by other pollinating insects was found to be fairly variable according to the time of the day. In the morning they had no effect on the fruit set as well as on the seed content of fruits either at Mosonmagyaróvár or at Feketeerdo. However, at the afternoon, when their intensity was greater, the correlation was a bit stronger.
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Continuous and discontinuous nectar secretion in some pear cultivars
77-79.Views:195Hourly nectar secretion was studied in five pear cultivars between 1997-1999. Some cultivars (e.g. ‘Csákvári téli') secreted nectar continuously during the whole day, offering both nectar and pollen for pollinating insects. Discontinuous secretion (e.g. cvs. ‘Viki', `Nyárig tartó 6/19') is less advantageous from the viewpoint of insect attraction. In some cases, however, discontinuity or continuity of nectar secretion varied even within a cultivar (e.g. 'Solymári cukor', ’Jó szürke’) in different years.
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Effect of different cultivation methods on strawberry’s antioxidant value
7-10.Views:573The small fruit and strawberry production is economically important in Serbian agriculture. The fresh fruit is sold in domestic markets, but the frozen and processed is mainly sold in foreign markets. The growers find themselves in an ever-expanding selection of the varieties, but besides the nursery and breeder’s descriptions of new cultivars, there are only few exact results for the biological and economical ability of the varieties, which makes easier to choose the proper cultivar. The performance of the varieties in modern strawberry production is worth to investigate by adaptive cultivation methods and production technique. In the case of new strawberry varieties we know neither their needs in production nor their real capability, so they have to be compared with an older, standard control variety (‘Clery’). The breeder’s manuals give only references for the needs of the production technique, of the variety, so it is necessary to have facts, which are based on objective testing results. In this work, a new variety (‘Joly’) is being compared with the control variety. Comparative study of individual varieties are required covering the antioxidant content of the fruits (FRAP) and variability of these amounts in different years of breeding as well as the production techniques under similar circumstances.
