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Pruning of plum trees and maintenance of balanced yielding
131-138.Views:254In this review, we give an overview of the pruning techniques that should be applied in commercial plum orchards. First, a detailed description of pruning for shaping the different crown types for the first, second, third, fourth and fifth years and the phytotechnical works is given for crowns with a circular projection area. Then, pruning for open crowns forms, such as the vase form is discussed. Following the shaping of the crown, it should be maintained by pruning. Detailed information is given on pruning for maintenance with special emphasis on the comparison of winter and summer pruning. In the following part of the manuscript, pruning experience is described separately for the major commercial plum cultivars in Hungary such as Cacanska lepotica, President, Bluefre, Stanley. Recommendations for cultivation systems under non-irrigated conditions are also included. Finally, light requirements, growth characteristics and suggested crown forms of the different cultivars are described for cvs. Ageni, Althan Tingle), Besztercei szilva Nm. 122, Bluefre, Cacanska lepotica, Cacanska rodna, Debreceni muskotály, Montfort, President, Ruth Gerstetter, Sermina, Stanley, Tuleu gras and Zöld ringló).
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Technologies developed to avoid frost damages caused by late frost during bloom in the fruit growing regions of Siófok and Debrecen
99-105.Views:406The aim of the study was to fi nd out which of the methods used to avoid damages of late frosts would be the most effective for the fruit growing practice. Three technologies have been tested in the regions of Siófok and Debrecen-Pallag. The antifrost irrigation proved to be the most advantageous. For that purpose microjet sprayers are used, which are thrifty and do not need for that purpose large containers. With the aim to secure an even distribution of water, the sprayers are distributed on three levels: above and inside of the crown as well as on the level of trunks. On a large scale, a single microjet above the crown level would be suffi cient. By means of a detailed analysis served to set the optimum intervals between spraying phases: with each 15, 10, 5 and 3 minutes during half a minute. The synchronous presence of water and ice below the freezing point, the released freezing heat plus the water used much above the freezing point (9–10 °C) altogether maintains the temperature above around 0°C near the fl owers or growing fruitlets, meanwhile, the surrounding air cools down to –8 °C. The effectiveness of the generally used anti-frost would be increased substantially by the former application of cooling irrigation, which delays the blooming date. The Frostbuster represents a new technology developed for the same purpose of frost defence. It uses butane burning and produces high (80-90°C) temperature with a strong blast of air. On the protected area sensors have been distributed for measuring temperature and relative humidity. The means of the measurements proved a rise of temperature, which was suffi cient to save the fruit trees until the difference is less than –3–3.5 °C. Our analyses stated that paraffi n candles avert the frost until –4 °C. Its success depends largely on the intensity of air movements. A small wind would be enough to frustrate the effect. The results show clearly the utility of Frostbuster and paraffi n candle combined is approved.
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Effect of pruning intensity on performance of apple cultivars in environmentally friendly production systems
65-67.Views:271The two worldwide accepted environmentally freindly production systems are integrated and organic. The two systems shows considerably differences in several practical production technology elements. These effects come forward in generative processes (e.g. flowering, fruit setting) and vegetative features (e.g. growth). The aim of our study was to study the effect of pruning intensity on growth features of cultivars in integrated and organic apple production. In early spring of 2009, we determined two pruning intensities (strong and week) on six scab resistant and tolerant cultivars. Strong pruning resulted in stronger shoot growth for all cultivars compared to weak pruning. It is obvious that pruning intensity had more effect on vegetative performance than conditional differences originates from integrated and organic production.
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Partial and total rejuvenation pruning of sour cherry trees
11-15.Views:324Sour cherry can be considered as a special fruit species regarding the growing characteristics, as most of the cultivars are characterized by strong balding. With the aging of the tree the inactive (passive) parts of the canopy are increasing steadily, so the productive cropping surface and the yielding capacity decrease significantly. In our experiments partial rejuvenation pruning was carried out in a 12 years old orchard, and total rejuvenation pruning was performed in a 21 years old plantation to regenerate the cropping surface of the trees. Thanks to the latter one the canopy of the sour cherry trees were regenerated during only two years. The yields of the rejuvenated trees in cv. ‘Debreceni bőtermő’ exceeded the yields of the control trees, as in the case of the cvs. ‘Érdi bőtermő’ and ‘Újfehértói fürtös’ approached it. At the same time the total rejuvenation pruning has a positive effect on the fruit size.
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Study on the micronutrient content of soil and leaf of an organic apple orchard in Eastern Hungary
7-11.Views:239The aim of our study was to investigate the relationship between micronutrient content of soil and leaf in an organic apple orchard. The experiment was carried out at the Experimental Site of the University of Debrecen, Centre of Agricultural Sciences at Pallag in an apple cultivar collection in Eastern Hungary in 2002-2004. The soil sampling was carried out twice per year, at the beginning and the end of the vegetation period in 2002, 2003 and 2004, respectively. The micronutrient content of leaf of seven apple cultivars (Jonagold, Mutsu, Idared, Red Elstar, Egri piros, Reka, Remo) was studied according to phenological phases of apple (April — September) to investigate the dynamism of plant nutrient uptake.
It was found that results of leaf analysis correlated with the obtained results of soil. According to the data of July, manganese and copper content of leaf is in the 'favourable' but zinc is the 'low' range of nutrient supply category. Moreover, there were significant differences in the micronutrient content of leaf among cultivars. From our results it is evident that more reliable data were obtained for fruit nutrition by determining of micronutrient content of soil and plant and calculate their ratios as well.
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The effect of the intensity and method of pruning on the growth and yield of the apple variety ’Idared’ under conditions of ecological and integrated growing systems
35-39.Views:454Summary: On the Experimental Farm of the Debrecen University at Pallag, a factorial experiment has been started at springtime of 2008 on an orchard of 12 year old apple trees ’Idared’ grafts on M 26 understocks. The first factor was the growing system (integrated versus ecological), the second was the intensity of pruning (strong versus moderate thinning of the crown), whereas the third was the method of pruning (shortening versus thinning of individual shoots). Measurements have been concentrated on shoot growth, flower initiation, fruit set and accumulated yield of two successive seasons. The following conclusions are made.
– In the ecological growing system, strong thinning proved to be beneficial for growth as well as for fruit bearing. – Strong thinning combined with shortening of shoots diminished yield in the first year, whereas
moderate thinning combined with shortening of shoots caused favourable growth and fruit bearing.
– In the ecological growing system, the moderate shoot growth was associated with better flower initiation, which increases the chances of alternate yielding.
– According to our results, the flower initiation of the ‘Idared’ was stimulated univocally by the thinning of shoots regardless of the intensity of pruning.
The right choice of the intensity and method of pruning is a decisive moment of a successful yield in the ecological apple growing system -
Branching features of apple cultivars in integrated and organic production technology
11-14.Views:304In our study, vegetative characteristics of 39 apple cultivars were evaluated in environmentally friendly production systems. Numbers of the branches of the central leader in different high zones were shown. According to our results, number of the branches of the axis was probably larger in the integrated production system, compared to the organic one, which is related to the conditional status of the trees. Based on our experiences training and maintaining canopies in integrated system was easier, as relative more extensive canopies were needed in organic farming.
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Cultivation systems in plum orchards
125-129.Views:299In this review, we give an overview of recent cultivation systems in commercial plum orchards. The aspects of selecting the shape of the crown and the spacing of trees are discussed first and then growth characteristics and the structure of the crow are described in detail. Finally, the wound healing and regeneration characteritics of plum trees are detailed which have an influence on the applied pruning technique.
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Integration of terrestrial laser scanning and spectral canopy scanner in horticulture applications
15-18.Views:289One of the most difficult challenge in the everyday practice to describe the canopy growing of fruit trees in an orchard. The photosynthetic activity is the basic of the primer production of plants. The measurement of leaf area and determination of the photosynthetic activity could be occurred with some elaborated methods between experimental conditions. In this article we present such an integrated methodology, which is ideal to determine the geometric and spectral characteristic of fruit trees between field conditions.We have carried out laser scanning technology to investigate the geometric-topological characteristics and parallel the active infra-red sensor to collect spectral data about an apple orchard. The surveys were worked out in an intensive apple orchard with drip irrigation system, protected by hail net in Study and Regional Research Farm of the University of Debrecen near Pallag. This study shows the filtering and interpretation methods of created data. The produced high accuracy data can be directly used in the precision horticulture. It could serve as a guiding data to implementation a future “virtual horticulture”. Higher spatial and temporal resolution could help for a better recognition of water balance of orchards.
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Organic versus integrated apple growing: II. differences in fruit quality parameters
61-63.Views:309The aim our study was to establish whether significant differences in nutrients uptake and quality of fruit exist
between organic and integrated grown apples. The study was performed at the orchard Fruit Research Station, University of Debrecen, at Debrecen-Pallag during 2002–2004. Diameter (mm), weight (g), firmness (N/cm2), dry matter (%) and Vitamin C in fruit were determined. Diameter data showed that the size of apples strongly depended on cultivars and organic apples were larger than integrated ones. Moreover, the effect of year and species strongly affected the apple diameter, size and weight. Measured data of firmness were good agreement in data of diameter and weight. Larger fruits have lower values of firmness due to the structure of fruit flesh. Dry matter content of apples varied between 14.66 and 18.07 in integrated, and 12.87 and 17.29 in organic apples according to cultivars. Values were affected by years and cultivars. From results it was evident that the dry matter content of apples affected by production system. It was lower in organic samples than integrated ones.Vitamin C content of apples was stronger affected by species and years than production system. -
Growing characteristics of apple cultivars in environmentally friendly growing systems
7-10.Views:255Nowadays the condition of the good saleability of the fruit is the application of controlled environmentally friendly technologies. Success of the growing is basically influenced by the production value of the cultivars, and their flexibility to the different technologies. In our examinations the effect of the integrated and organic farming system has been evaluated on the growing characteristics of the apple cultivars. According to our results the trunk thickness of the trees both in the initial and both in the later bearing period is higher in the integratedproduction compared to the organic farming system. This differences most likely caused by the variance of the crop load.
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Production technology and fruit tree nutrition
39-42.Views:153Fruit yield quality and quantity are effectively enhanced if healthy vegetative conditions are ensured. These optimal conditions — i.e. the balance between shoot development and yield — can be achieved by the rationalization of the production technologies, such as:
- reduction of the size of the crown
- adaptation of the severity and method of pruning to the conditions of the actual year
- removal of the shoot tips
- timely fruit thinning
By establishing an improved level of plant nutrient uptake, this will ensure a healthy balance between shoot growth and yield.
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Cooling irrigation as a powerful method for microclimate modification in apple plantation
33-37.Views:286Irrigation in some countries is a horticultural practice mainly used only to supply water. At the same time the use of microsprinklers have a powerful influence on the changes of temperature in orchards. When the air’s temperature is high (about 20 °C or higher) the evaporative cooling irrigation significantly decreases the plants’ surface temperature and air temperature. The cooling effect is stronger when the air is dryer. By using cooling irrigation regularly, canopy temperature can be decreased so that the beginning of blooming can be delayed. Also if the blooming is early and frost probability is high, serious damages can happen in orchards. The beneficial effect of cooling irrigation is the temperature reduction and frost protection. InMarch 2010, one month earlier than the expected blooming an irrigation system was established to produce anti-frost treatment and regulate the micro-climate of a Gala apple orchard which belongs to the University of Debrecen (Hungary). The objective of sprinklers was to cool the air by increasing water evaporation and relative humidity. The position of the micro-sprinklers was planned in three levels (around the tree trunks, a few cm near to the soil surface, in the crown region and above the crown, a half meter higher). The results showed that the water sprayed in the orchard by micro-jets influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect. When water was applied at intervals of 15 minutes for ten times a day from 8 am to 18 pm, the air, flowers and bud’s surface temperature could be kept low.At certain days when the temperature was higher than 10 °C, irrigation was used at night time in similar 15 minutes intervals, from 18 pm and 6 am. The beginning of bloom could be delayed for more than ten days. The Gala apple variety blooming dynamics was characterized by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control one in spite of the equal temperatures measured in the plots. Under Hungarian climatic conditions, the method was successfully used to delay blooming dates. The main result was the diminution of the frost damage in the spring that assured apple yields.
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Performance of sweet cherry cultivars grafted on Colt rootstock
7-10.Views:657In this paper growing characteristics and fruit bearing parameters of ‘Lapins’, ‘Kordia’, ‘Sweetheart’ and ‘Regina’ sweet cherry cultivars grafted on vigorous Colt rootstock were evaluated at the University of Debrecen, Pallag Experimental Station. Based on our data five years old trees can be described with homogenous strong growing, but very week yielding (2.1-3.1 kg/tree), as while fruit size varies between 26.2 and 27.2 mm. Producing the examined cultivars on Colt rootstock with high plant density requires higher attention and more interventions (root pruning, sawing the trunk) during the technology.
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A review of the orchard management in organic fruit production
43-49.Views:238The elements of orchard management have a determining role in the success of organic fruit production, therefore, it is essential that they are applied properly. The present review gives describes some aspects of the orchard management such as site selection, orchard soil, rootstocks and cultivars, planting materials and plant density, crown shape. Then, one of the most important elements, pruning is discussed with special emphasis on winter pruning, condition and apical dominance, degree and method of pruning, summer pruning. After pruning, an overview of fruit thinning, irrigation, soil cultivation, soil protection (cover plants and mulching) and fertilization is given.
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Economic figures of plum production at national level of Hungary
111-113.Views:270In Hungary, natural conditions are optimal for growing plums. In spite of that, plum production was not a successful business in the past years. The reasons of it are, first of all, the utter fluctuation of yields and of the producer’s prices, increment of direct costs of production, dwindling incomes and uncertainties on the market. Serious problems are caused by the high rate of aged plantations, which are not counterbalanced by new plantings. Decisive is the “loose” ranging of the branch by the Union regarding plum production, which is expected for the sake of enlarging production and markets. Our aims are to analyse the management of the eight-year-long period, 2002-2009, and the fate of components of husbandry. The results presented are means of an utterly heterogeneous population of enterprises, being hardly suitable to make actual decisions, but they may enlighten upon challenges and recognise tendencies within the branch.
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Organic versus integrated apple growing: I. differences in soil and leaf parameters
57-60.Views:241The aim our study was to establish whether significant differences in nutrients uptake and quality of soil and leaf exist between organic and integrated grown apples. The study was performed at the orchard Fruit Research Station, University of Debrecen, at Debrecen-Pallag during 2002–2004. Macro and micro elements were measured in soil and plant samples. Analyses of variance of soil nitrogen data indicated highly significant differences between the two management systems (P < 0.001) for each examined nitrogen fraction. Analyses of variance of soil phosphate data indicated significant differences (P < 0.05) between the two management systems for orto-PO4 3– contents. Our data indicated that highly significant differences between the two management systems (P < 0.001) for magnesium, copper, and zinc; while significant differences between the two management systems was at P = 0.007 for calcium. Three year’s data of leaf phosphorus, sulphur and zinc were not shown significant differences between production systems. Nevertheless manganese and copper contents of leaves were higher in the organic orchard compared to the integrated one.
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Evaluation of generative accomplishment of new apple cultivars in Hungary
11-15Views:345In a two year study, 14 new apple cultivars (cvs ’Gala Venus Fengal’, ’Gala Decarli-Fendeca’, ’Galaval’, ’Jugala’, ’Gala Schnitzer (S) Schniga’, ’Red Cap Valtod (S)’, ’Early Red One’, ’Jeromine’, ’Crimson Crisp (Co-op 39)’, ’Red Topaz’, ’Wilton’s Red Jonaprince’, ’Red Idared’, ’Fuji September Wonder’ and club cultivar) were studied in Eastern Hungary at Nyírbátor. The following parameters were measured: trunk cross sectional area (cm2), harvest time with yield (date, kg/tree, number/tree), fruit size (mm), fruit surface color (%), and color intensity of the fruit surface (1-5). According to our two year assessments regarding, the best generative accomplishment was achieved for the cvs ‘Gala’ sorts trained to slender spindle and the cv ‘Red Jonaprince’ trained to super spindle. According to the trunk cross sectional area the ‘Gala’ sport trained to slender spindle showed the strongest growth among the 4 years old trees, while the cv ‘Fuji SW’ and the cv ‘Jeromine’ presented lower vegetative accomplishment. The ripening time of the cultivars started at the end of August and finished at the beginning of October. ‘Gala’ mutants trained to slender spindle provided the highest yields. Fruit size of all cultivars reached the market required standard, however, cvs ‘Red Jonaprince’ and ‘Red Idared’ produced large fruits over 90 mm. The fruit size of the ‘Gala’ sort was 72–75 mm. Most of the cultivars showed high fruit surface color and color intensity.
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Pruning and incidences of diseases and pests in environmentally oriented apple growing systems: some aspects
24-29.Views:275In Hungary, fruit growers are increasingly interested in environmentally oriented growing methods, such as organic and integrated systems. The main factor in creating such systems is the establishment of a system of cultivar-pruning-plant protection based on production technology. Therefore, our aim was to examine the susceptibility of apple cultivars to diseases and pests and the effect of pruning technique on diseases and pests in organic and integrated growing systems.
Two pathogens (Venturia inaequalis, Podosphaera leucotricha) and two pests (Leueoptera malifoliella, Pannonychus ulmi) were observed in organic and integrated systems under "strong" and "weak" pruning techniques. Our results showed that, compared to integrated production, the pathogens and pests infected the trees more in the organic system. The pruning technique affected mainly the cultivars susceptible to diseases and pests. In general, the "weak" pruning technique correlated with a higher level of damage caused by diseases and pests than the "strong" pruning technique, especially in the organic growing system. The reason that techniques should be carefully chosen is that shoots grow faster and more vigorously after employing the "strong" pruning technique. This supports a better preservation of the trees, as a result of reduced susceptibility of plant tissues to diseases and pests.
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The effect of cooling irrigation on the blooming dynamic of plum
57-59.Views:325The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.
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Evaluation of the growing and fruit bearing characteristics of the ‘Lapins’ sweet cherry cultivar grafted on rootstocks with different vigor
15-18.Views:419Sweet cherry is currently considered as a fruit with high interests. The amount of the produced yield is well saleable in the world and also in Hungary year by year, moreover often there is a shortage with the high quality fruits. Researches with the sweet cherry production focus on the intensity growing all over the world, namely the realization of producing with small trees ensuring high quality and quantity. In our examinations ’Lapins’ sweet cherry cultivar was evaluated grafted on rootstocks with different vigor (Gisela 5, Gisela 6, Colt) at the University of Debrecen, Pallag Experimental Station. According to our results trees grafted on Colt rootstock can be described with very low yields due to the excessive high vigor. Trees with Gisela 5 and Gisela 6 rootstocks showed excessive high productivity, as size of the fruits did not reach the required values.
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Evaluation of crop yield and fruit quality in organic apple production
7-10.Views:233In 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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Effects of excessive weather on the micro-climate of apple plantations under the hail protection nets
81-85.Views:348The general utilisation of hail nets is spreading all over the world and in Hungary too. Hail nets are at present the only tool, which
is able to prevent heavy hail damage in agricultural crops. Besides its numerous advantages, there are also deleterious side effects, e.g. it
changes the microclimate of the crop stand. Our study aimed to observe the differences, which characterise the physical status of crop stands
under the protection of hail nets compared with the stands in open air under various meteorological conditions: high or low temperature, calm
or windy atmosphere and their possible combinations. The results indicated that on hot and calm days the difference may attain 3–4° C. On
cool summer days, the difference was only 1.5 ºC. The hail net influences the relative humidity of the air, which means on ho summer days
often 7-8% differences. Conditions of radiation may also differ conspicuously. Measurements prove the reduced global radiation on sunny
summer days to 70%. This impairs as a rule the development of fruits reducing their quality and also its quantitative traits. Sunburn is, on the
other hand, significantly prevented by shadow. -
Specialities of the vegetation start and level of primary fruit set affect fruit quality
17-22.Views:197Thinning 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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Growing characteristics of apple cultivars and canopies
7-10.Views:332In our study we aimed to evaluate the growing characteristics of new prospective apple cultivars and their canopies. The following parameters were measured: I) thickness of the trunk and the central leader, II) ratio of the trunk thickness and the basic branches (Zahn indexes), III) number of the branches of the central leader, and iv) thickness of the branches of the central leader. The main branches of the trunk and the central leader tend to over thickening in the case of cvs ‘Red Idared’, ‘Wilton’s Red Jonaprince’ and ‘Jeromine’. The density of the branches of certain parts of the canopy was too low for cvs ‘Crimson Crisp’, ‘Wilton’s Red Jonaprince’, ‘Fuji September Wonder’ and ‘Red Idared’. The density of the branches of certain parts of the canopy was too high for cvs ‘Gala Venus Fengal’, ‘Wilton’s Red Jonaprince’ and ‘Red Cap Valtod’. Relationship was found between the tapering dynamics of the central axis and the thickness of the main branches, which was stronger in super spindle canopies than in slender spindle crown forms.