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Variability of the data indicating the fertility of different plum varieties
51-55.Views:1060Self-fertility and fertility at conditions of open pollination in plum varieties is strictly determined by genetic factors. However, rates of fruit set are highly variable according to growing sites as well as to seasons, which may result from a couple of inner and outer conditions, but mainly from the method applied in seizing the facts of fertility in the experiments planned including the number of replications of treatments. During three successive years, 4-16 trees of each of the four plum varieties have been selected and 16-64 branches were tagged either for checking their fertility as pollinated freely or isolated excluding the access of foreign pollen. The data of fruit set have been processed in order to determine the variability of the data, subsequently, the number of replications necessary to make reliable decisions. Both autogamy and open pollination displayed multiple differences between branches and trees studied.
A number of 20 branches are needed yearly for each variety, the branches should be distributed on 5 trees at least for checking the autogamy, whereas on 10 trees for the results of open pollination. Each variety and treatment should be represented in three seasons, at least because of the different weather conditions.
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Investigation of flowering dynamics of the basil (Ocimum basilicum L.) and its consequences in production
74-80.Views:474The flowering dynamics of Ocimum basilicum L., (a common population maintained at the UHFI) was studied with the aim to create an exact and practically applicable method for definition of phenological phases.
According to our observation the development of individual flowers of the basil can be characterized by 8 distinguishable phases, which must be considered for description of the actual phenological stage of a spike.
An accurate model was created for the unambiguous description of flowering process of different flowers within the spike and for the individual plant as a whole. The new flowering index formula is calculated from the number of flowers weighed by their phenological phases.
The time dependence of flowering is presented by functions fitted to values of the flowering index. The results reflected different patterns of the main inflorescence, the inflorescences formed on the side shoots in the first or in the second half of the flowering period. However, for description of the flowering process of the whole plant, a sigmoid function proved to be the appropriate model.
The accumulation process of the essential oil could be characterized by the flowering index values. They showed close correlation (r=0.964) at high probability.
The new method assures an exact definition of phenological phases in basil. Its application seems to be optimal during breeding procedures, seed production and even in production of high quality drugs, according to the requirements of the Good Agricultural Practice (Guidelines for GAP, 1998).
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The effect of storage to optical properties in case of two apple fruit varieties
33-36.Views:924The keeping quality of fruits is a very important factor in storage point of view, since it could be elongated the consumption time of fruits. In many cases the storage may be necessary, e.g. in short time it is not able to market due to the rich harvest, or all fruits could sell in markets throughout the year. The keeping quality of various fruit species is greatly different; moreover it could be observed some differences between the varieties as well. In our research, we have investigated the spectral properties of the external surface and fl esh of two ripe apple varieties – Jonagored and Granny Smith – before and after storage (about 3°C and about three weeks). The hyperspectral investigation was carried out with AvaSpec-2048 Fiber Optic Spectrometer. The experimental results represented the differences between healthy and chilling injured apple fruits. Furthermore, some indices were created to given countenance to the spectral differences.
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Work quality assessment of a cherry sorting machine
57-62.Views:988The conditions of the cultivation of marketable cherries are diverse. Choosing the production site on the basis of the climatic conditions, selecting the most appropriate variety taking into account the region and the purpose of the production, utilization of the optimal production method, to ensure the required water and nutrients supply, frost and hail protection techniques, modern technology in crop protection, and professional performance of harvesting and handling, to name just a few of the most important issues. The objective of present study is to determine the qualitative characteristics of the UNITEC cherry sorting machine.
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Studies on the drought responses of apple trees (Malus domestica Borkh.) grafted on different rootstocks
29-36.Views:1400The 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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Calculation of climatic probability of winter and spring frost damages in the main peach and apricot growing districts of Hungary
99-106.Views:921The probability of winter and spring frost damages experienced in peach and apricot plantations has been assessed in 5 growing regions of Hungary (Szeged-Szatymaz, around the lake Balaton, Mecsekalja, hills of Buda, Mátraalja) and (Mecsekalja, hills of Buda, PestGodo116, Duna-Tisza Mize, Matra-Bükkalja) during the period between 1951 and 2000.
Frost tolerance of flower buds on a given shoot sample is expressed by the mean value assessed after frost damage (LT50), and the meteorological records of the growing sites raised between 1951 and 2000 are used to calculate the probability of frost damage. In peach, the difference between growing sites and between varieties may become two fold as for the chance of repeated frost damage at a probability of 50 %. In apricot, the probability of frost damage may exhibit differences between growing sites up to 20 % as for susceptible varieties, and 16 % for frost tolerant varieties. Frost damage may vary between 4 and 18 % depending on the genuine frost tolerance of the varieties. Peach is afflicted by low temperature causing substantial losses of yield at the highest probability in the region Szeged-Szatymaz and at the lowest in Mátraalja. Apricot is, on the other hand, most endangered in the Duna-Tisza Mize region, while the lowest probability of frost damage is expected around Mecsek and Buda.
The critical period of frost damage in the mid of January in Szeged-Szatymaz region, in Mecsekalja the mid of February showed the highest probability of frost damage. All growing sites are frequented at high chances by frost damages occurring during and closely after the blooming period. Duna-Tisza köze is mainly afflicted in early March, whereas Mátra-Bükkalja in mid of January and each March.
The probability of temperatures below zero degree has been assessed in all the 5 regions observed. Around April 5-8 the probability of freezing temperatures diminishes steeply at all sites, whereas the risk of frost increases again around April 9— 11. That climatic peculiarity of should be taken into consideration in choosing growing sites or varieties.
Postulating the effects of a global warming up of the climate, the chances of avoiding frost damages at different growing sites by delaying the blooming dates are considered. According to our calculations, the delay of blooming by 5 days may diminish the risk of frost damage by 4-20 % at the growing sites examined, whereas a delay of 10 days reduces the risk by 37-85 % in both fruit species.
Calculations offered an answer on the question of climatic changes, whether the probability of winter and spring frosts damage changed during the 50 years. The long list of data shows the diminishing chances of winter frosts, while the probability of temperatures risking spring frost damages increased after the early 1970-es up to now.
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Nectar production of quince (Cydonia oblonga Mill.) cultivars
87-94.Views:1267Nectar 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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Variation between some apricot varieties in regard to flowering phenology in Boldogkôváralja, Hungary
7-9.Views:867The aim of this study was the estimation of blossoming of 14 apricot cultivars in Boldogkôváralja in 2009, 2010 and 2011 seasons. And this will help growers to select appropriate varieties to their weather conditions. For this target the blooming period of 19 apricot varieties of different origin was observed in three subsequent years. There was no large difference in the beginning of blooming in the different years, and the greatest variation between the start date of flowering was about 1 to 3 days as the place of experiment site near to northern border and also, length of flowering period of apricot trees is also inversely related to date when blooming started. The little differences in flowering dates and flowering periods due to the high temperature through the three seasons of study.
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Flower density and winter damage of apricot and peach varieties
53-56.Views:753Hungary is located on the northern boundary of economical apricot and peach production. The present assortment of varieties and the actual, not adequately selected growing sites cause a permanent risk of winter and spring frosts in their cultivation. The field observations are performed at Debrecen, the Experiment Station Pallag, on 20 apricot and 21 peach varieties. The flower density among the varieties attained 3-4-fold differences. Three categories have been suggested for both species. The density was inferior in Hungary established varieties compared with the new varieties of foreign origin. The minimum temperatures of January 9, 2009 was –17,6 °C , and of December 21, 2009 also –17,6 °C. In some varieties the damage of buds attained 100%. For estimating the yield security, we need to consider also the flower density and the frost damage together. For a mediocre yield, we need a flower density in both species of at least 0.2 living bud/cm. The results confirm the statement that in Hungary, the revision of growing sites is indispensable in order to develop a profitable and competitive apricot and peach growing industry.
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Microclimatic studies on different aged apple plantations
7-11.Views:996The purpose of measuring parallel canopy and out of canopy microclimates was to find out in what extent climatic parameters measured in different aged canopis differ from each other and from the values characteristic to out-of-canopi areas. The importance of phytoclimatic researches seems to lie in the fact that if the reactions of fruit trees towards meteorological elements are continuously followed, we have the possibility to provide growers with information. These pieces of information are like defining the optimum time of phitotechnical interventions (summer pruning, sorting sprouts, thinning fruits, etc.), the necessity of applying mulching, defining the method and time of irrigation and applying plant protection activities. By means of phytoclimatic researches, it is possible to react to unfavourable meteorological impacts within a certain extent. It is also possible to successfully reduce the risks of late spring and early autumn frost damage, as well as the risks, content and measure of experienced heat and water stress conditions by finding out about the physical characteristics of the canopis' internal area.
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Flavonoids, chalcones and phenyl-propanoids in apple and pear flowers
35-38.Views:290The presence of phloretin-glycosides in the hypanthium and pistil of apple and pear flowers can be verified. Thin layer chromatography is a reliable method for detecting phloretin, gained by acidic hydrolysis. The dominance of phloretin was equally characteristic for flowers in apple (`Sampion', 'Freedom') and pear (Tem-re Bosc', 'Conference') cultivars treated with various bioregulators (Biomit, Bion 50WG, Regalis), no significant difference could be found visually as compared to control samples. Chlorogenic acid and caffeic acid was detected in all apple and pear samples, rutin was present only in pear, and hyperoside was found only in a few apple samples.
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Agroclimatological properties of growing sites assigned to apple and pear production in Hungary
95-97.Views:847Apple and pear growing sites in Hungary are classified into four regions according to the Hydro-thermic Coefficient: dry, moderately dry. moderately humid and humid. Most of the plantations of apple and pear are located in regions considered as moderately dry and moderately humid. Within that category, the two respective species have different preferences, i.e. the ecological features of Hungary give different opportunities for apple and pear growing. Apple is grown almost everywhere in the country, successfully. The selection of cultivar-regions is needed mainly for increasing competitiveness on the market. Main apple growing regions are listed in 3 large groups. For the definition of cultivar-regions, mainly the configurations of soil and precipitation, i.e. conditions of the soil and opportunities of gaining water were decisive. Market factors are also considered. The area assigned to pear is much less than that of apple, in Hungary. Some well known and popular varieties would require high air humidity which cannot be presented in most of Hungary. Therefore, the possibility to establish regions for pear varieties is restricted, we have to create a particular micro-environment. Two groups are potential. The first one comprises sites where the annual precipitation is 700 mm, at least. There, apple and pear production would compete each other. In more dry habitats (less than 700 mm annual precipitation), micro-environments should be found and only drought-resistant, mainly summer-ripe cultivars should be chosen with, preferably, low tendency of sclereid formation. In that case, neither irrigation could help to produce adequate quality in varieties sensitive to low air humidity.
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Temporal changes of the frequency of spring frost damages in the main fruit growing regions in Western Hungary and in East Hungary
81-87.Views:1079Most of the risk in Hungarian fruit growing is the damage caused by late spring frosts. The frequency of late frosts seems to increase nowadays. The aim of the study was to check this contention: what is the real probability of the damages. Based on earlier experiences, the physiological LT50 function has been elaborated for new fruit varieties, which are eligible to moderate the danger when being threatened by frost. By means of this technique, the probability of freezing is distinguished between frost susceptible, frost resistant and medium frost resistant fruit species and varieties around their blooming time. The degree of frost damage depends on the duration and severity of the low temperature and not at least on the frost tolerance of the plant. For that purpose, the frequencies of frost damages were studied at two Transdanubian and two Trans-Tisza fruit growing sites by means of a meteorological database for the 60-year-long period 1951–2010. Being aware of the LT50 values changing during the phonological phases of the fruit trees from budding, bloom, fruit set and fruit growth, the number and date of critical (frosty) days could be settled. An important role is attributed to the orographic relief and the height above the sea level of the site, as 20–30 m differences and expositions may become decisive within the same plantation. The spatial distribution of damages is also dependent on the air circulations within the Carpathian basin. At the southern and northern borders of the country, especially valley bottoms represent additional risks of frost. Most spring frost damages are experienced in April 20–22, and cause heavy damages by temperature minima between – 3°C and – 6°C. The severity of damage depends largely on the temperature of the preceding few days. The earlier bloom the heavier damage is expected. The study is emphasising the importance of the varieties. Frost tolerance of some varieties may lower the risk of spring frosts by 40–50%, as experienced on the plantations. The quantifi cation of the risks based on data raised during the last years will be suitable to defi ne the security of yields of each growing site successfully.
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Colour and water content detection of sweet cherry by portable spectrometer
23-26.Views:35495Based on the most recent data, the average amount of sweet cherry produced in Hungary is around 10-12 thousand tons. Therefore fast and effective method is important for sweet cherry fruit quality analyses. The aim of the study was to examine the applicability of reflectance measurements for sweet cherry fruit quality analyses. In our experiment five cherry species (Vera, Cristalina, Germersdorfi, Noir de Mechet, Canada Giant) were examined in order to measure the spectral differences between species. Further more, spectral alteration was examined between different health and maturity status of the fruits in the case of a specified, the Germesdorfi species. The four new indices are appropriate tools for cherry quality analysis. Thus reflectance measurements can also support more precise and automated fruit selections. The methods for the differentiation of species could also be viable at a concerned habitat; however, the climate, habitat and soil conditions strongly affect the yield quality. Concerning the fast determination of water content, WBI could be a reliable method for the assessment
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Nutritional aspects of producing fruits organically
69-74.Views:799Recent interest to avoid use of agrochemicals in fruit growing to safeguard environmental and human health has stimulated interest in organic fruit production (OFP) all over the world. Organic production requires a holistic approach to agricultural ecosystem management. Because of the perennial nature of orchards, this is not a great departure from conventional orchard management, except that corrective techniques are limited primarily to naturally derived materials. Organic mineral nutrition management hinges on two principles: 1) practices that lead to the build up and maintenance of soil that is biologically active and high in organic matter; 2) supplementing the mineral nutrients provided by the soil with fertilizers from approved sources. Organic orchards should be sited on land with superior soils and preplant soil preparation to increase organic matter and correct any sub-optimal soil characteristics. For successful organic fruit growing the following statement should be considered:Weed management is critical to reduce competition for nutrients and water. Soil and leaf analysis provide the basis for correcting mineral nutrient deficiencies or imbalances in organic production. It may be necessary to use a number of strategies to supply mineral nutrients over the life of the orchard. The slower, natural methods applied require a management approach that is simultaneously patient and dynamic.
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Fruit drop: II. Biological background of flower and fruit drop
103-108.Views:975The most important components of fruit drop are: the rootstock, the combination of polliniser varieties, the conditions depending of nutrition, the extent and timing of the administration of fertilisers, the moments of water stress and the timing of agrotechnical interventions. Further adversities may appear as flushes of heat and drought, the rainy spring weather during the blooming period as well as the excessive hot, cool or windy weather impairing pollination, moreover, the appearance of diseases and pests all influence the fate of flowers of growing and become ripe fruits. As generally maintained, dry springs are causing severe fruit drop.
In analysing the endogenous and environmental causes of drop of the generative organs (flowers and fruits), the model of leaf abscission has been used, as a study of the excised, well defined abscission zone (AZ) seemed to be an adequate approach to the question. Comparing the effects active in the abscission of fruit with those of the excised leaf stem differences are observed as well as analogies between the anatomy and the accumulation of ethylene in the respective abscission tissues.
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Flower visiting activity of honeybees on fruit species blooming subsequently
12-16.Views:1107In the small demonstration orchard of the College Faculty of Horticulture at Kecskemét the blooming time, the flower density and the honeybee activity was observed at a number of cultivars of 20 flower species during four consecutive years.
Fruit crop species were in flower during 3-4 months altogether. The blooming period of them was classified into five groups as early (almond, apricot, gooseberry), middle early (sweet cherry, red currant, currant-gooseberry, black currant, white currant, peach, plum, sour cherry), middle late (pear, strawberry, apple), late (black elder, quince, medlar, raspberry, blackberry-raspberry) and very late blooming period (blackberry). The blooming period of the members of the groups of early and medium early blooming often coincided partly and the same happened between the medium and the medium late as well as between fruits of late and very late flowering.
The flower density of some fruit species is extremely variable (currant-gooseberry, medlar), while at others it is fairly stable and evenly dense in consecutive years (sour cherry, sweet cherry, strawberry). At other fruit species it is moderately changeable. Some fruit species tended to attract more honeybees than others (plum, apple, quince, medlar) and some of them tended to attract much less (black elder, pear) but most species can be regarded as of medium attractivity.
On the flowers of some fruit species (pear, strawberry, quince) honeybees gathered pollen predominantly. At most fruit species however pollen and nectar gathering behaviour seemed to be gradually changing during the season. Namely most honeybees tended to gather pollen at the flowers of the early blooming fruit species, but on the other hand typical foraging behaviour gradually shifted to nectar gathering at the flowers of fruit species of moderate and late blooming periods.
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Effect of foliar spraying with algae suspension on leaf and fruit quality parameters of apple varieties
35-38.Views:1318Foliar nutrition experiment was made to investigate the effect of algae products on fruit quality of apples (Malus domestica Borkh.). The study was conducted in 2011 at Siófok inWest-Hungary on cv. ‘Jonagored’ and ‘Idared’grafted on M9 rootstock. In our trial leaf diagnostic and fruit quality measurements were made to study the effectiveness of applied products. Relative leaf chlorophyll content was determined by a portable chlorophyll meter. Fruit weight and shape index were measured. Fruit inner qualifying parameters like titratable acid content and Brix value were also determined. It can be stated that the used products had traceable effect on investigated fruit parameters. Although, leaf N content was not effected by treatments significantly, relative leaf chlorophyll content significantly increased by both treatments. Used products significantly increased the fruit weight and shape index. Applied treatments significantly decreased the pH of pulp. Treatments increased the acid contents (fumaric, citric, malic) of apples and decreased the amount of monosaccharides. It means that the applied treatments pushed out the ratio of acid/sugar.
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Applied spatial analytic tools in orchards with special regard to agro-ecology
17-19.Views:1003Our investigation was carried out in several orchards in Hungary. This study reviews applicability of the different spatial analytical techniques in orchard especially models based on surface relief, such as digital elevation model, digital terrain model, slope and aspect maps. In recent time, the generation of digital elevation model has become a popular examination method. However, the elevation models generated from contour lines or elevation points could be applied to evaluate agro- ecological potential of fruit orchards to some extent. The highest deficiency of these models is the fact that these show the altitude of soil surface only and do not demonstrate landmarks on the surface. Consequently, the calculation of the radiation value results data relating to soil surface. The terrain model generated and applied by our team demonstrates fine surface texture and the landmarks in the orchard, so it is suitable for further examination.
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Training systems of fruit trees in Hungary
123-127.Views:1114Growing sites and soil conditions of Hungary warrant profitable production of several temperate fruits at elevated levels of quality. The climate of the Carpathian basin is a mixtures of three main climatic zones the prevalence of which may change seasonally: Atlantic, continental and Mediterranean, therefore, growing sites are rather various. Temperature minima of the winter and late spring frosts are the main elements of risk. In choice of the system of cultivation, regularity of yields and intensity are to be observed equally. Regular yields are particularly aimed in stone fruit cultures.
For apple and pear plantations of high density required for intense production are promoted favourably. Accessories of intense orchards (irrigation, supporting system, rootstocks, phytotechniques, etc.) are important. In peach and plum trees are trained to funnel-shape crowns, in general, intense-types are possible in plum, only. In apricots, a Hungarian speciality, the "umbrella" type of crown is applied, almost exclusively, according to Papp. In sweet and sour cherry, the harvest technique, manual or mechanised, according to the intended utilisation, are determining the form of training.
Red and black currants as small fruits are grown mostly as bushes or hedgerows without any supporting system designed to facilitate mechanical harvest. Raspberries and blackberries are grown as hedges on trellis. Gooseberry is a special case, being a low, thorny bush difficult to be picked. Thus grafted small trees are attached to a wire-trellis which helps to solve problems of plant protection too.
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A short introduction of new apple varieties obtained
135-137.Views:619A short introduction of new apple varieties obtained
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Effect of hail protecting nets on the quality of apples
77-80.Views:1055Today, successful fruit growing depends largely on the security of production. Among the technological elements of a secure growing system, the use of hail protection nets serves special attention. Components of security are the regularity, conspicuous large yields with excellent quality, which determine the prices and profitability as well (Szabó et al., 2010). In the European Union, most of the apple growing countries produce higher yields by 10-20% than Hungary. The conditions of better yields are partly due to a more favourable ecological milieu, partly to more developed technologies and serious discipline of the operations. Our own competitiveness could be developed first of all in those moments. As a consequence of global climatic changes, excesses of weather, i.e. hail-storms became more frequent. Different methods of protection against hail are developed abroad but also in Hungary. The examination of effects of the hail protection nets compared with the check without nets has been the purpose of our experiments. The growing system was the intensive one with high planting densities. Fruits of the two subsequent years have been compared as grown with and without hail protective nets. It turned out that in one season when shoot growth was stimulated, the shadowing effect of the net increased in addition the growth and at the same time braked the differentiation of flower buds, which exerted negative effects on yield of the next year. Let alone this phenomenon, the quality of fruits was not influenced by the hail protection net.
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Incidence of virus fungal diseases on three stone fruits cultivars in Hungary
107-109.Views:793In this two-year study, incidence of Polystigma rubrum on plum, and Apiognomonia erytrostoma on apricot were evaluated on several stone fruit cultivars in Hungary. Results showed that most apricot cultivars expressed symptoms caused by A. erytrostoma, graded between 2 and 3 (10-50%) by the end of the summer in 2005 and 2006. The most tolerant apricot cultivars were Budapest and Mandulakajszi while the most susceptible ones were ’Magyar kajszi’ and ’Piroska’.Assessments made on plum showed that most of the plum cultivars were tolerant or lowly susceptible to P. rubrum such as ’Ageni’, ’Althann ringló’, ’Bluefre’, ’Cacanska najbolja’, ’Silvia’, ’Ruth Gerstetter’, ’Tuleu gras’ and ’Utility’. The most susceptible plum cultivars to P. rubrum were ’Besztercei clones’ and ’Debreceni Muskotály’.
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Organic versus integrated apple growing: I. differences in soil and leaf parameters
57-60.Views:1630The 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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Fruit drop: The role of inner agents and environmental factors in the drop of flowers and fruits
13-23.Views:1340The basic conditions of fruit set (synchronic bloom, transfer of pollen, etc.) still do decide definitely the fate of the flower (Cano-Medrano & Darnell, 1998) in spite of the best weather conditions (Stösser, 2002). Beyond a set quantity of fruits, the tree is unable to bring up larger load. A system of autoregulation works in the background and causes the drop of a fraction of fruits in spite of the accomplished fertilisation and the equality of physiological precedents (Soltész, 1997). There are also basically genetic agents in action. The further development of fruits maintained on the tree depends mainly on the growing conditions (e.g. water, supply of nutrients, weather adversities, pruning, fruit thinning, biotic damages, etc.), which may cause on their own turn fruit drop especially at the time of approaching maturity.
