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Interaction of nutrient supply and crop load of apple trees (Malus domestica Borkh.)
33-35.Views:148Long term fertilisation trials were combined with storage experiments with 'Jonathan' apple trees and fruits to study influence of tree nutrition on quantity and quality of crop. The site of experiments is a typical Carpathian-basin environment with loamy silt soil, high lime content and arid summers. Conclusions has been drown from six years' set of data. Augmented levels of soil fertilisation increased cropping capacity of apple trees, however, the fruit load has not met with cropping capacity in every year. More the def cit came into view in crop load, less the fruit quality resulted in. The deficit in cropping capacity, however, could not have been determined with simple rates as fruit weight per trunk circumference or similar. Better determination was obtained where foliar nutrient contents were correlated to crop per tree figures. In general terms, the N and Ca content in leaves increased with yields when K and P content formulated reciprocally. When storage quality of 'Jonathan' apple fruits were related to crop load (kg/tree), influence of crop deficit became visible. As the crop load and foliar nutrient levels interacted, the fruit quality (number of disordered apples after 6 month of storage) subjected of both physiological phenomena. Higher determination degree were obtained when crop load was assessed together with single or multiple foliar analysis data.
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Exploring and preserving old apple cultivars of the Carpathian basin
9-13.Views:170In a few scattered orchards of the Carpathian basin one can still find our most common historical apple cultivars and certain traces of traditional cultivation. We consider it an important part of the Department's breeding work to explore old apple cultivars which can be used as parent partners and sources of resistance, to identify them pomologically as well as to examine the production and marketing value of old cultivars recommended for cultivation in ecological production and in gardens. This paper documents the results of expedition and collecting work carried out in three regions of the Carpathian basin (foot of the Carpathian Mountains, Transylvania, Aggtelek karst area), and also the saving of old Hungarian apple cultivars preserved until present in the English National Fruit Collection. A total of more than 100 old apple cultivars and variations, as well as 13 valuable genotypes were collected during our explorations in the above mentioned four areas. A further aim of our work is to contribute to the protection of still savable archaic fruit production relict= areas and to the preservation of cultivars in the certain regions, and also to promote the recognition of the aesthetic landscape value of old apple trees and endemic orchards of old cultivars. Our good co-operating partners in this work are Aggtelek National Park, Farmer Club of Visk and the consultation centre of Hungarian horticulturist training beyond the border in Nyárádszereda.
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Sunburn incidence of apples is affected by rootstocks and fruit position within the canopy but not by fruit position on the cluster
45-51.Views:221Authors investigated sunburn incidence of apples on the combinations of three different growth inducing rootstocks (M.9,MM.106 and seedling) and five varieties (‘Smoothee’, ‘Golden Reinders’, ‘Granny Smith’, ‘Gloster’ and ‘Jonagold Jonica’). Symptoms were classified as sunburn browning, sunburn necrosis and photooxidative sunburn. The frequency of symptoms was recorded at various parts of the canopy (N, E,W, S, and lower canopy, upper canopy) and on the cluster (terminal, lateral). Cultivar susceptibility varied between 0.30 and 5.65% on M.9 rootstock, ‘Granny Smith’ seemed to be the most susceptible cultivar whereas relatively low percentage of damaged fruit was observed for ‘Gloster’. On MM.106 and seedling rootstocks, damage level was significantly lower than on M.9. Remarkable differences were not observed in the share of the three sunburn types between cultivars. The most common symptom observed was sunburn browning. Far less fruit was affected by sunburn necrosis and photooxidative sunburn. Photooxidative sunburn symptoms were not found on ‘Granny Smith’ and ‘Gloster’ fruits on MM.106 rootstock. Latter cultivar did not show sunburn necrosis symptoms either. With increasing growing vigor of the rootstocks the share of sunburn browning increased. Fruits with sunburn symptoms were found in a great majority on theW quadrant of the trees. This was true for all cultivars. Remarkable differences in the location within the canopy of affected fruits between the three types of sunburn were not observed. Specific distribution of sunburned fruit was observed along the vertical axis of the canopy, too. Most of the damaged fruit were found in the upper canopy. This is particularly true for trees on vigorous stocks such as MM.106 and seedling. On M.9 rootstock, depending on cultivars 5.9 to 38.9% of sunburned fruit was located in the lower canopy. Most common symptom in the lower canopy was the sunburn browning, however symptoms of sunburn necrosis were not found at lower canopy level. Low rate of photooxidative sunburn was observed such lower canopy conditions. Sunburn incidence was very similar on king or side fruit. Significant differences were not found in the share of each sunburn types between fruit positions on the cluster. This was not influenced by rootstocks either.
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Effects of activated charcoal on rooting of in vitro apple (Malus domestics Borkh.) shoots
98-101.Views:134Rooting of in vitro 'Royal Gala' shoots was studied under different conditions of root induction and root elongation phase. The rooting capacity was affected by both rooting phases. Very high rooting percentage could be reached with both liquid and solid root induction media. Raising the temperature from 22 °C to 26 °C during root induction phase increased the rooting percentage. Presence of activated charcoal in root elongation media can affect the number of roots per rooted shoots and can increase the rooting percentage, the length of roots and the rate of survival depending also on other conditions during rooting. Presence of NAA in root elongation media reduced the number and the length of roots considerably. Favourable effect of activated charcoal on rooting was mainly due to adsorption of NAA.
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Anatomical study of the leaves and petioles of scab resistant and susceptible apple cultivars
53-57.Views:134Anatomic 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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Healthcare values and potential uses of the new Hungarian apple varieties on the basis on fruit analysis
25-28.Views:179Biological active compounds and valuable characteristics of some apple varieties and candidates were measured in our trials. Fruits of ’Rosmerta’, ’Hesztia’, ’Cordelia’ and ’Artemisz’ are recommended to enrich the Hungarian assortments for fresh consumption and choice of new tastes. Based on examined parameters it can be assumed that novel Hungarian resistant varieties are suitable for juice and fruit concentrate production, and due to high pectin content of their remaining pomace these varieties can be raw material of pectin production as well as they are also suitable for jam production mixed with other fruit species. Furthermore, functional food industrial product having high quality can be produced by using novel resistant varieties because of their high pectin and polyphenol content. Beside of their high market value their suitability for growing among orchard conditions is confi rmed by lower costs of production because of less plant protection treatments.
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First selections of the Hungarian apple breeding program for multiple resistance
9-13.Views:138The aim of the first Hungarian apple breeding program for multiple resistance started in the beginning of the nineties is to widen Hungarian apple assortment by good quality, resistant apple cultivars with excellent productivity and ecological capability to the most important fruit growing areas in Hungary. In the first years of seedling production we made early selection for susceptibility to apple scab in greenhouse. Alter this, field observation of susceptibility to powdery mildew, scab and canker and a yearly negative selection was carried on. From 1997, fruit quality was evaluated as well, and from 2001 the resistance of shoots to Erwinia ainylovora (Burrill/Winslow et al.) was examined using inoculations in greenhouse conditions. From the progenies of crosses in 1992 and 1993, six candidates were announced to national recognition out of hybrids examined for more than a decade. Descriptions of these selections from 'Prima' progenies and the most important data of their resistance, growing habit, morphological characteristics and fruit quality are shown in this article.
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The effect of nitrogen supply on specific yield and fruit quality of apple (Malus domestica Borkh.)
7-21.Views:168The aim of the present study was to determine the effect of nitrogen supply on yield and fruit quality of apple cultivars and to explore the relationships between canopy density and the different fruit quality parameters.
The experiments were carried out at Kálmánháza, in Eastern Hungary in a private orchard in 2003-2004. The response of four apple cultivars ('Elstar', 'Gala Prince', 'Granny Smith', 'Idared') to different nitrogen dosages was studied. The assessed and calculated indices were: yield, fruit diameter, fruit height, shape index, fruit mass, firmness, dry matter content and colouration. The results indicated that nitrogen fertilization has a significant effect on the yield and fruit quality of apple cultivars. The calculated specific yield values were reduced by the application of nitrogen via the increase in the volume of the canopy. An opposit trend was observed for fruit diameter, fruit height and fruit weight, which increased with increasing nitrogen supply. The reduced shape index caused flattening of fruits.
However, the improvement of fruit quality via increasing nitrogen dosage is only virtual, since these dosages increase the fruit size, but firmness, dry matter content and colouration are diminished, which decreases the value of the fruits on the market.
The authors also studied the relationships between canopy density responsible for assimilation and light supply of the fruits and the different fruit quality parameters. The closest linear inversely proportional relationship was found in the case of colouration. There was a negative linear relationship between canopy density and firmness or dry matter content. The relationship between canopy density and fruit mass could be described by a quadratic polinomial function.
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Fire blight (Erwinia amylovora) resistance in apple varieties associated with molecular markers
53-57.Views:223The invasive bacterial disease fire blight, caused by Erwinia amylovora has the potential to destroy fruit tree orchards all over Europe. Effective plant protection methods are lacking in many countries, highlighting the increasing importance placed on identification of germplasm with heritable disease resistance. Recent l y. a promising QTL (quantitative trait locus) was identified on linkage group 7 in the apple cultivar 'Fiesta· which is derived from ·cox's Orange Pippin' . I n the present study, 144 Swedish and foreign apple cultivars were analysed with the SCAR markers AE I 0-375 and GE-8019. which flank-. this QTL. Twenty-nine of the analysed cultivars had both markers. 78 had either AE I 0-375 or GE-8019, and 37 cultivars did not carry an) of the two markers. Seventeen cultivars. 7 with both markers and I 0 not having either of the two markers, were then inocoluted with the bacterium in a 4uaran1i ne greenhouse test. Cultivars carrying both DNA markers were significantly less susceptible than cultivars lacking the markers, P<0.001. Cultivars that were most resistant had both markers and had 'Cox· in their pedigree. Unrelated cultivars with the markers may still lack the QTL.
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Differences of pollen and pollenkitt attractiveness of some cultivated and ornamental apples for honeybees
145-150.Views:124Differences in the attractiveness of pollen according to plant families and species for the honeybees had been examined by researchers, but pollen samples of cultivars were not tested yet. This examination attempts to evalu2te the differences in attractiveness of pollen of some cultivated and ornamental apples to honeybees. We applied biotest with equal amounts of hand collected pollen samples and by a nucleus of bees with brood. The evaluation was based on the number of visitation by foraging honeybees on the samples during the time of the experiment which was determined. Pollenkitt samples were also tested in a separate experiment.
The data were analysed by variance analysis and significant differences were found according to the number of bee visitation in the attractiveness of the pollen and pollenkitt samples of apple cultivars.
The visualisation of pollenkitt was done by light microscope and SEM.
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Metaxenic pollen effect of scab resistant apple cultivars on the fruit of apple
47-52.Views:147As a part of an apple breeding program, we have examined the pollen effect on the fruit appearance and inner quality of different apple cultivars in the Corvinus University of Budapest Department of Fruit Science. Five apple cultivars ('Golden Reinders', 'Regal Prince', 'Rewena', 'Renora', 'Idared') have been crossed by the pollen of some new and some traditional cultivars in our experiment. The measurements were carried out in the analytic and fruit examining laboratory of the Department of Fruit Science. The diameter, height and stem length were measured by digital caliper. We have also examined the squash ratio, soluble solid- and acidic content. Sugar content was calculated by a schedule released by the International Sugar Committee (ISC). From the sugar- and acidic content, we could also count the Pomona-value.
We have observed interesting effects according to some attributes in some crossing combinations with the help of statistical analysis. Crossing 'Golden Delicious' with 'Freedom', 'Prima', and 'Baujade' have resulted in smaller fruit size than other combinations. No significant differences could be observed on `Golden Reinders' fruits according to metaxenic coloration in the year of the examination. On the other hand the color modifying effect of pollen donating cultivars have manifested on the red fruits of 'Regal Prince' (Gala Must). `Freedom' as a pollen donating cultivar has resulted outstanding value in our consistency measurements. Squash ratio was the highest in combinations pollinated by 'Prima' and `Reglindis'. We have noticed balanced values when measuring inner qualities, only `Reka' has caused lower acidic content. Significant differences have been found in combinations according to the number of frivolous seeds. No frivolous seeds were found in the combinations 'Golden Reinders' x 'Freedom' and 'Idared' x 'Prima'. Almost two frivolous seeds were found in the fruits of the combination 'Renora' x 'Sóvári' in average.
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Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology
19-23.Views:348Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle.
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Some structural characteristics of the flowers of apple cultivars with different susceptibilty to fire blight
21-23.Views:113Several morphological characters of the hypanthium (size and form of the surface, the shape of the hypanthium) and anatomical traits (number and pattern of stomata) of apple cultivars (Malus domestica L.) with different susceptibility to fire blight were studied. The size of hypantium surface was calculated by modelling the hypanthium with a truncated cone. Three types of hypanthium surface form have been revealed: straight, convex and a complex "shouldered" one. The angle between the style and the wall of the hypanthium was narrow or wide. The stomata on the hypanthium surface can be arranged in a zone in the middle third of the hypanthium or dispersed more or less evenly. The number of stomata/flower substantially differed among the cultivars examined. The highest stomata number was detected in the flowers of the tolerant cultivar (Freedom)
No single characteristics of the hypanthium could convincingly be correlated with susceptibility to fire blight. We suggest, however, that combination of morphological properties that sustain moist environment in the hypanthium contribute to susceptibility.
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Recent findings of the tree fruit self-incompatibility studies
7-15.Views:184This review endeavours to collect all recent and substantial contributions to the quickly deepening fields of tree fruit self-incompatibility studies and hence updating previously published reviews. Studies carried out to discover the molecular basis of gametophytic self-incompatibility are summarized and a newly described model for the solanaceous plants is also outlined. We describe recent findings in all economically important fruit tree crops involving apple, European pear, sweet and sour cherries, almond, Japanese plum, sloe, Japanese apricot, European apricot and peach. Additional DNA sequences are now available for both the pistil and pollen component genes in several species and their molecular, evolutionary or economic implications are discussed in the light of the fruit setting behaviour.
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Effect of pruning on disease incidence of apple scab and powdery mildew in integrated and organic apple production
57-61.Views:230In a three-year study, the effect of two winter pruning treatments (strong and weak) on apple scab (Venturia inaequalis) and powdery mildew (Podosphaera leucotricha) was evaluated on six apple cultivars (`Rewena', `Elstar', 'Liberty', 'Gala', 'Pilot' and `Jonica') in two environmentally-benign apple production systems (integrated and organic). Results on apple scab showed that compared to the integrated production system, the pathogen caused significantly more infection on the leaves of cvs. `Elstar', 'Gala' and `Jonica' in the organic production system. The effect of pruning treatments on apple scab was mainly detectable on the cultivars susceptible to the disease such as cvs. 'Gala' and `Jonica'. The weak pruning correlated with a higher level of apple scab infection than the strong pruning, especially in the organic production system. Primary mildew infection was very low in both protection systems (below 2 %), therefore, effect of pruning on primary mildew infection could not be analysed. Low secondary mildew incidence was detected in the organically treated orchard part; however, incidence of powdery mildew was significantly higher (P> 0.05) on cvs. 'Elstar', 'Pilot' and `Jonica' in the integrated orchard part compared to cvs. 'Gala', 'Rewena' and 'Liberty'. The highest incidence of mildew was on cv. 'Elstar'. Pruning had very low effect on incidence of secondary mildew infection on leaves.
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Studies on the drought responses of apple trees (Malus domestica Borkh.) grafted on different rootstocks
29-36.Views:369The 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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The inheritance and durability of scab resistance in apple progenies
39-46.Views:128In order to select the appropriate parent cultivars and maintain the durability of resistance, it is important to clarify the mechanisms of inheritance of scab resistance depending on the parents. It has been known that the progeny segregation ratios based on scab-resistance do not depend only on the genotype of the resistance locus but also on the genetical makeup of the donor and recipient parents as well as on the susceptible parent.
The aim of this study has been to demonstrate what factors in the Vf, Vr and VA scab-resistant cultivars — combined with susceptible and resistant parents — affect the inheritance and durability of resistance in seedlings in their first 4 year's growing four years' growth. After inoculating apple seedlings sown in 2001 with the suspension of Venturia inaequalis (Cke.) Wint. in the greenhouse, we studied the segregation ratios of the progenies into reaction classes. Seedlings showing resistance in the greenhouse were also evaluated for scab-resistance after they had been moved to the field and had naturally been infected with the pathogen in 2002 and 2004.
The majority of our results obtained in the greenhouse test, similarly to earlier experiences, have not justified monogenic inheritance at the phenotypic level. The effect of susceptible parent cultivars on the segregation ratio of progenies have become apparent again. The high infection rate of seedlings in the field trials, which had previously exhibited varying degrees of resistance in the greenhouse test, has raised concern. Our data has raised further doubts, concerning the durability of Vf resistance in Hungary. It is assumed that the composition of natural field populations of Venturia inaequalis in Szigetcsép has changed. The complexity of Vf resistance has been confirmed. The high infection rate in the progenies derived from Vf resistant cultivars draws the attention to the importance of utilizing additional sources of resistance.
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Farm-scale evaluation of two widely used sanitation practices for reducing primary inoculums of apple scab in organic apple production
15-18.Views:176Effects of two widely used sanitation practices were evaluated at farm-scale level on leaf degradation and primary infection by Venturia inaequalis in an organic apple orchard (Eperjeske) on two apple cultivars (Jonathan and Prima) from 2011 to 2013. The tested sanitation practices were eradication of fallen leaves by collection and disc cultivation. Treatments of eradication of fallen leaves by collection and disc cultivation reduced signifi cantly (P< 0.001) leaf litter density with 70–85 and 40–55%, respectively, compared to untreated plots in both years. Above treatments in the same order reduced spring scab incidence with 40–50, and 10–20%, respectively, compared to untreated plots. Incidence of leaf scab in autumn was not signifi cantly lower (P< 0.05) in the treatments in the years.
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Effects of crop load on tree water use in apple (Malus x domestica Borkh.)
29-31.Views:117Sap flow rate measurements were carried out during two consecutive ('on' and 'off') years in an apple orchard cv. 'Florina' M.26 to analyse the effects of various crop load on tree water use. Sap flow rate was measured by thermal dissipation method in trunks of nine trees from June to the harvest. Crop load was between 0.2-9.0 fruits • cm -2 of trunk cross section area (equal to 0.5-35.0 fruits•m-2 of leaf area), trunk diameter varied between 4.7-8.7 cm.
Total leaf area was estimated by leaf counting or using shoot girth and leaf area relationship. In both years, fruit growth rate was determined by measuring diameter of 280 marked fruits with 7 days frequency. Fruit volume calculated as a function of fruit diameter based on a previously determined relationship.
Total leaf area of trees ranged from 4.4 to 19.5 m2 and it was closely related to trunk cross section area. At high crop load the fruit growth rate peaked in August with 0.51.tree-l.day-1 and the leaf area specific total fruit volume reached 61 m2 before the harvest.
There was a linear relationship between total leaf area and daily water use, while the leaf area specific water use was influenced by crop load rate. The relationship was described by piecewise linear regression with the breakpoint at crop load rate of 12 fruits•m2 of leaf area. At low crop load the slope of the fitted regression line was less than at high crop load rate.