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Variability and differences of growth vigour in the set of 36 genotypes of apricot (Prunus armeniaca L.).
30-34.Views:129Growth vigour of 36 apricot cultivars and new hybrids grafted on apricot seedling rootstock (Prunus armeniaca L.) was evaluated on the base of measurements of stem girth from the 411' to the 10th year after planting. There were differences in growth vigour of genotypes under study. In the evaluated set of genotypes the control cultivar 'Veecor may be classified as a genotype with below-average growth vigour. Only four genotypes (-Reale d'Imola-, Sanagian -Moldavskii krupnoplodnyl and 'LE-2385') were found with significantly higher growth vigour than that of control cultivar 'Veecot' in years of the end of experimental period. Two genotypes (Farmingdale', -LE-SE0-24') were found with significantly higher growth vigour only at the beginning of experimental period and one cultivar ('Vivagold-) with significantly lower growth vigour in the first four years. Genotypes with different growth vigour can be used in further breeding programmes and/or as components inhibiting or supporting the growth in indirect vegetative propagation. Within the whole experimental period, the rank of growth vigour of genotypes practically did not change. This was demonstrated by highly significant or significant coefficients of correlation existing between individual pairs of years (r=0.32+ to r=0.96++). As far as the time difference between years in individual pairs of years was higher, the correlation coefficients were lower. In individual years, variability of growth vigour was relatively low and ranged from 9.83 to 13.64%.
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Climate change effect on sour cherry production in Central Hungary
61-66.Views:177Consideration of the soil and climatic conditions and their expected changes is very important in planning of new orchards. This research focuses on the expected climatic conditions and opportunities of sour cherry production in Central Hungary in the periods of 2021–2050 and 2071–2100, compared to the base period of 1961–1990. Results show that in the near future the expected changes are mostly favourable for sour cherry production, the utility values are increasing in most of the subregions. By the end of the century the utility values show further increase in the formerly colder subregions. However, in some subregions the utility values slightly decrease because of the appearance of the extreme dry and warm year types, though their values remain at the level of the base period or even higher.
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Organoleptic evaluation of sweet cherry varieties
7-13.Views:586The extraordinary abundance of precipitation in 2010 (somewhere around 1000 mm) influenced highly the development of taste and flavour in cherry fruits. As stated, only a few varieties out of 27 were acceptable as for commercial quality. Under the given climatic conditions, actually ‘Bigarreau Burlat’ earned 965.11 points and proved to be the best in the early ripening group. In the mid season group, three varieties earned more than 1000 points (‘Giant Red’, ‘Carmen’ and ‘Vera’ grown at Nagykutas and Pallag), whereas in the late ripening group ‘Germesdorfi’ sent from Csenger (1084), ‘Linda’ (1070.07) and ‘Lapins’ (1052) received recognition. Correlation has been tested on the basis of 27 varieties between the individual properties. We sated that the most important attributes, which influenced the general impression of decision makers are the following: form and size of the fruit (r=0.835 and 0.797), furthermore juiciness (r=0.776), taste (r=0.876) and sweetness (0.875). Crispness was considered to be typical to cherry (r=0.743). Relation between acidity and sweetness was also essential to determine the acceptance of the cherry character.
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Evaluation of sour cherry varieties grown with environmental technology
39-41.Views:460The evaluation of a produce is an important moment of predicting its success on the market. The general impression, which is decisive, when a consumer chooses to purchase the commodity, should be interpreted in more objective, measurable terms. Primary data have been collected on fresh fruits derived from different growing technologies by organoleptic tests and the data filled up in the forms are processed with correlation analysis. The components were: taste, aroma, flesh firmness. The coefficients of correlation showed that the rest of characters as the appearance, juiciness, and the sugar/acid ratio.
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Anatomical study of the leaves and petioles of scab resistant and susceptible apple cultivars
53-57.Views:149Anatomic 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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Researches concerning the selection of some nectarine varieties as genitors for the breeding program in Romania
44-46.Views:107Researches concerning the selection of some nectarine varieties as genitors for the breeding program in Romania
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Economic figures of apple production at national level of Hungary
Views:178After the change of the political system the main looser was in Hungary the fruit-growing branch. The yields varied at high amplitudes, and the production increased slowly in spite of multiple planting activities. The European Union ranked fruit production “loosely” to the products, which allows the extension of its markets. Thus I decided to analyse the economic relations of the period between 2002 and 2008 in order to reveal the main effects of movements. The pictures are the resultants of a heterogeneous population, which cannot be influenced on the level of enterprises. But they are utilised for the recognition of challenges and trends on the level of branches of economy. The immediate costs increased the production monotonously, which cannot be compensated by a thrifty management of the general costs. Thus costs of production increased dramatically, whereas the marketing of products could not realise the values.
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Self-incompatibility in pears (Pyrus communis L., Pyrus serotina Rehd. and Pyrus ussuriensis) Review
87-91.Views:190Self-incompatibility system and allele pool of three different pear species, European pear (Pyrus communis), Japanese pear (P. serotina) and Chinese pear (P ussuriensis) are displayed. Several inconsistencies and the absence of the harmonization of three different allele series are revealed in the European pears. By collecting data from several reports eight incompatibility groups of Japanese pear cultivars could be established. A self-compatible genotype is analysed in details and shown to be a stylar-part mutant. As Japanese pear was the first fruit tree species from which S-ribonucleases were identified, the history of S-genotyping from the beginning to the latest achievements and technical developments can be also monitored from the experiments enumerated. In Chinese pears, seven S-alleles and one incompatibility group could be identified.
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The effect of Regalis® (prohexadione calcium) on the reduction of fire blight (Erwinia amylovora) severity in apple trees
61-66.Views:174Due to the lack of effective and non-phytotoxic materials for control of the blossom and shoot blight phase of fire blight in pome fruit trees, two novel control strategies have emerged: shoot growth retardation by bioregulators and applying resistance inducer compounds. Prohexadione calcium (ProCa) is the active ingredient of the bioregulator Regalis® registered in several European countries. The reduction of shoot growth elongation is the most obvious effect of ProCa. Furthermore, it causes significant changes in the spectrum of flavonoids and their phenolic precursors, leading to the considerable reduction of susceptibility to fire blight.
In Poland, potted one-year-old apple trees of cvs. Gala Must grafted on M.26 and Sampion on M.9 (in 2001) as well as Gala Must on P.60 (in 2002) were treated with Regalis® at a range of concentration of 250, 150 or 150 + 100 ppm, respectively. The inoculation of shoots was made with the strain No.691 of E. amylovora (107 cfu/ml), on the 7th and 21st'day after treatments with Regalis. In Hungary, during the years of 2002 and 2003 one-year-old container grown apple trees of the cvs. Idared/M.9 and Freedom/M.9 were treated with the prohexadione-Ca, the active ingredient of Regalis® 100, 150 or 200 ppm, two weeks before inoculation with the Ea 1 strain of E. amylovora (107 cfu/m1).
In Poland, the suppression of fire blight in shoots reached up to 80%, depending on concentration and application time of Regalis®. In Hungary, the effect of prohexadione-Ca treatments, determined by the length of necrotic lesion developed, proved to be better than that of streptomycin used for comparison.
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Post-effects of cytokinins and auxin levels of proliferation media on rooting ability of in vitro apple shoots (Malus domestica Borkh.) 'Red Fuji'
26-29.Views:231Rooting ability of in vitro apple shoots of 'Red Fuji' grown on proliferation media with different hormone content were tested at three IBA levels in root induction media. Rooting percentage could be slightly increased with an increase in IBA concentration in proliferation media. The highest IBA concentration (3.0 mg 1-1) in root induction media showed strong inhibitory effect on rooting capacity of in vitro shoots. The highest rooting percentage (95%) could be achieved by shoots grown on proliferation media containing TOP or BA+KIN as cytokinins before rooting.
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Legal harmonization of the Hungarian horticulture conditioned by the accession
23-28.Views:154In the EU-horticulture is treated with special care. As far as its regulation is concerned, different orders are in force to single branches. The regulation of the branch of medicinal plants is related chiefly to the processing, because the overwhelming part of the basic material is to be imported. More preoccupation falls to the ornamental plant branch, although both the production and the turnover are controlled by the market. Irrespective of this fact, the quality standards are high. Also the production and the sale relations are carefully circumscribed, with special regard to the processing procedures. In the control of the quality an important role devolves on the producers' organizations, likely in our country on the so-called TESZ-es (Cooperatives for production and sale). In this regard the domestic prescriptions took much over of the EU practices.
The structure of sales in vegetable and fruit branches is continously changing, the demands of the consumers are more and more satisfied by the super- and hypermarkets. Their marketing organizations offer almost the half of the total of quantity commodities. In consent with the processing industry they raise quite severe requirements to producers. These requirements are to be taken into account also among our circumstances. There is a similar situation valid in the viticulture and winery. Within these branches we are able to compete on good chances of adapting our regulations to those of the EU. In this area there falls also responsibility to our vine-growing communities. Particulary a watch must be kept over the reputation of our renown quality wines and the results already achieved must be protected.
The competent ministries — at first the Ministry of Agriculture and Rural Development — has already shown great flexibility to the desires in regard to the expectable legal harmonization. The legislative, registrative and controlling activities are to be continued in this mentality.
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Evaluation of the vegetative and generative performance of new apple cultivars in the Nyírség region
39-44.Views:231In this paper we examine apple varieties, which are planted expansively in the development apple orchards of the Western- European countries, but about its production characteristics we don’t have or just few practical experiences in Hungary. These varieties can be described with regular and high yields, aesthetic and alluring appearance in their origin places, what ensure profitable producing for the growers. Under the Hungarian climate which tends to be often extreme (hard cold winters, late spring frosts, summer drought, heat stress) these varieties may behave differently, so before the substantial planting it is expedient to carry out variety evaluations to avoid the later failures. The place of our experiments is located in the Nyírség representing adequately the ecological conditions of the surrounding areas, so the gained results can be adapted easily in the biggest apple production site of Hungary. Regarding the vegetative and the generative parameters of the 14 examined varieties (’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’, club cultivar) we found significant differences. The ratio of the thickness of trunk and the main branches showed that the trees have an optimal canopy structure in accordance with the Zahn principles, so they are in harmonious growing balance. The ‘Gala’ sport trained to slender spindle produced the highest yields, while the ‘Fuji’ and the ‘Red Delicious’ sport trained to super spindle can be described with the lowest values. All the cultivars reached the eating quality (65-70 mm), from which the ’Red Idared’, the ’Red Jonaprince’ and the ’Red Cap’ produced outstanding fruit size (81-85 mm).
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Spatial and temporal variation of extremely abundant maxima of precipitation in Hungary during the period between 1951 and 2010
107-114.Views:343The study deals with the accumulated database of 16 meteorological stations in Hungary during a period of 60 years. The purpose was to reveal the spatial and temporal structure of the appearance of extreme values in the daily distribution of data concerning precipitation. We strived to answer the question whether the frequency of incidences of daily maxima did they change or not during the 60 year-long period in the main growing regions of the country. It is demonstrated on geographical maps how the size and frequency of precipitation episodes ensued, and what are the typical traits of changes in intensity as well as in frequency of happenings projected according to their spatial and temporal distribution. From the point of view of fruit and vegetable growing, it is of prime interest what kind of frequency and intensity of changes occurred in precipitation. The temporal distribution of extremities though did not seem to change signifi cantly in some areas, but the recognition of changes may help conspicuously the planning and the choice between alternatives of species and varieties as well as technologies of horticultural managements for the long run. Extremely intense rains during a short time may cause erosion and stagnant water, thus we have to know what are the odds of risk. The temporary distribution of changes helps us to judge upon the reality of anxieties, which are expected according to the existence of trends. Seasonal or monthly distribution is visualised by maps, what is expected and what is accidental as for a decision in planning. The spatial distribution of coeffi cients of variation help us to decide what is the local chance of extreme happenings at different parts of the country and what is its coeffi cient of uncertainty. The risk of any undertaking dependent on conditions of weather could be expressed numerically by a coeffi cient of risk.
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The role of meteorological variables of blossoming and ripening within the tendency of qualitative indexes of sour cherry
7-10.Views:244We analyzed the relationship to sour cherry quality parameters of average temperature, maximum temperature, minimum
temperature, night and day-time temperature, precipitation and climatic water balance variables. Three cultivars of sour cherry were included
in the selection: “Debreceni bôtermô”, “Kántorjánosi”, and “Újfehértói fürtös”.We conducted regression analyzes on the three varieties, but
present only those that proved to be the best fit.We couldn’t find any significant differences in the weather tolerance of the varieties. The data
base of sour cherry quality parameters covers the 1998 to 2008 intervals. The researched parameters were the following: dry matter content
(%), sugar content (%), C-vitamin (mg), total acid content (%). Maximum temperature, the difference of night and day-time temperature and
minimum temperature all have a significant correlation with the investigated quality parameters of sour cherry. Minimum temperature shows
a quadratic relationship with sugar content, while night and day-time temperature differences show the same with dry matter content. The
other weather parameters had a linear correlation with the quality parameters of sour cherry. The research results show that an increasing
amount of precipitation causes decreasing tendency in total acid content of sour cherry, so that increasing temperature has a positive influence
on total acid content. Big differences in night and day-time temperature also has positive effects on the dry matter and sugar content of sour
cherry while the amount of precipitation has a negative effect. High minimum temperatures cause decreasing sugar content respiratory energy
losses are significant if dawn temperatures do not drop considerably.A more favourable climatic water balance has a positive effect on vitamin
C content in cases of a large negative water balance, vitamin C content is generally low. -
Examination of valuable ingredients of some wild fruits
71-74.Views:169A possible way of the development of Hungarian agriculture is the selection and growing of new fruit species and varieties featuring special qualities, with high biological nutritive and health protecting properties due to their natural composition. A reserve for such new fruits is the native dendroflora, e.g. those wild-growing trees and shrubs of Hungary, which bear edible fruits. The publication is giving a summary of chemical analyses done on the fruits of the plants listed below. The research team on the project started the work in 2001 with
woody species (genera) as follows:
- common elder (Sambucus nigra) clone named Szcs-1, Szcs-2, Szcs-3, Szcs-4, Szcs-5, SzcsK-1, SzcsK-2
- dog rose (Rosa canina) types: clones named Sz-1, Sz-2, Sz-3, Sz-4 and Sz-5 .
- native rowans: Sorbus dacica, S.rotundifolia, S. degenu, S.bakonyensis cv. Fánivölgy
- hawthorns: Crataegus monogyna, C. orientalis,C..v lavallei.
- cornel cherry: Cornus mas cv. Császló.
The present paper is reporting on the content of the following compounds in the fruits: dry matter (refractometric values), total acid content, ascorbic acid, 13-carotene, pectin, minerals and carbohydrates. The results have shown that these wild fruits have excellent composition. Besides their curative effects, their content of minerals, ascorbic acid and 13-carotene has surpassed that of the traditional fruits. These fruits are rich in ascorbic acid, 13-carotene and pectin. The high content of the above-listed, biologically active compounds makes the new wild fruits studied suitable for the preparation (and later: mass-production) of special curative and exclusive products.
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Sex expression of flowers in cultivated sweet and sour cherries
50-52.Views:157During the period of 1968-1972 nine sweet cherry varieties were investigated by the author on mazzard seedling rootstock, moreover cv. Germersdorfi óriás and cv. Münchebergi korai sweet cherry cultivars grafted on mahaleb, cv. Korponai and cv. Sukorói cherries were observed on rootstocks of cv. Cigánymeggy sour cherry seedling, too.
Yet, there are other relations between the different parts of sweet cherry flowers too, which perhaps indicate the effect of rootstocks in Cerasus scions. The flower structure shows feminine character on mahaleb, the effect is intermediate on mazzard, however, the sour cherry rootstock strengthens the male character.
Four sour cherry varieties as cv. Cigánymeggy C. 404. cv. Érdi nagygyümölcsű, cv. Meteor korai and cv. Pándy C. 101 were studied on three rootstocks: mazzard, mahaleb and Cigánymeggy C. 215 seedling rootstocks between 1976 and 1980.
The pistil length, stamen number and relative stamen number diverged significantly on different rootstocks. The results revealed a close negative correlation between the pistil length and stamen number, furthermore noticing that, in the self-fertile cv. Meteor korai and cv. Újfehértói fürtös presented increasing of the relative stamen number, so the fertility decreased, while in the case of self-sterile varieties the change was favourable.
Summing up the results, it is obvious, that the fertility of flowers can be modified by rootstocks and the ecological factors cause sex reversions on different combinations.
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Growing experiments with a medicinal mushroom Agaricus blazei (MURRILL)
45-48.Views:221The demand of natural and medicinal products has been increased for the past years. These products are often made from herbal and medicinal plants, and recently the mushroom products are much called. Nearby some well known species (like Lentinula edodes or Ganoderma lucidum) some not respected biomedicines are available in Hungary. Agaricus blazei (Murrill) is a Basidiomycota fungus, with almond-like taste and nice texture. This medicinal mushroom proved to be useful in cancer therapy and against some bacterial and viral diseases. In our experiment we tested 8 Agaricus blazei strains on fermented mushroom compost. The yields, average mushroom size, productivity and biological efficiency of the species were measured. Our data demonstrate that it is possible to get fruit bodies less than 2 months, and strain "837", "2603" and "MaHe" are suggested for further experiments. These strains gave the highest yield and efficiency in the cultivation.
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Phenological and fl ower morphological studies on different plum and prune cultivars
43-52.Views:24120–22 and 5–7 years of kind collection of 100 cultivars studied phenology and fl oral morphological basis of characteristics in 1994–1998 and 2009–2011. The varieties were collected 3–5 trees in the gene garden, all were on C. 359 myrobalan seedling. Detecting differences between the test cultivars are suitable for stamps, and also show that relatively short-term observations are useful for describing the comparison, to distinguish varieties. The taxonomic ordination of cultivars and groups of fruits suitable to distinguish colors shown that the fl owering and ripening time, the nature of the reproductive organs and even Sharka-rate sensitivity is associated with those groups. Differences between the age of trees mainly sexual organs and fertility were shown. Affecting rate of climatic effects was not as large as the first line of erratic rainfall, air temperature spikes or possible values would be expected. The results of the breed, a gene bank of perception, in particular, the localization of hybrids, clone-type variants are useful in the analysis. Among other things – this is due to late-maturing, relatively well-stored temporarily, and not-blue plums, Sharka-infected tolerant or resistant varieties selection (cf. SURÁNYI 2013a-c) and will be disseminate in Hungary.
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Applied spatial analytic tools in orchards with special regard to agro-ecology
17-19.Views:324Our 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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Powdery mildew infection dependent on weather factors in vineyards near Keszthely in 2008
55-59.Views:212Weather conditions are extremely influential on grapevine productivity and quality. High temperature and humidity makes favorable conditions for powdery mildew infection respectively. The meteorological data around Keszthely, Hungary show the vegetative period is dryer and warmer than it was closely hundred years ago. We examined the development of powdery mildew infection on two variet ies Vitis vinifera L. cv Italian Riesling and cv Merlot in relation with meteorological data. No primer infections were appeared in the vineyard. The year of 2008 was quite ideal for the accumulation of Erysiphe necator in the experimental vineyard. Although the dry summer can lower the infection, but if the high temperature is coupling with rainfall, the possibilities of powdery mildew infection is going to grow higher during the upcoming years.
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Relation of sour cherry blooming dynamics and meteorological variables
17-23.Views:250The aim of our research was to identify the role of weather parameters in the development of the start date and length of blooming. In order to achieve this, we examined how meteorological conditions of a particular year influence the start date and length of blooming in different years (dry, wet, cool, hot, sunny, cloudy). The meteorological parameters were the following: maximum temperature, minimum temperature, average temperature, precipitation, length of sunlight, difference of daytime and nightime temperatures, potential evaporation-PET, Huglin-index,Winkler-index, climatic water balance which can be calculated as a difference of precipitation and potential evaporation. In this study we wanted to find out whether early start of blooming results in a longer blooming period or if there is a generally faster blooming period when blooming starts later. Based on the results we can say that early start of blooming resulted in extended blooming period for three sour cherry varieties at the examined production sites. The start of blooming showed the closest relation with the difference of average daytime and nightime temperatures of the 30-day period prior to blooming. Significant relation was also detected with the thermic indexes as well as with maximum temperatures, climatic water balance and the degree of potential evaporation.We examined how weather 30 days prior and during blooming influenced the length of phases. Results showed that precipitation prior and during blooming is in significant relation with the length of blooming. We detected significant relation between daytime and nightime temperature differences and the length of blooming. The nature of the relation indicates that blooming periods were shorter in case of increasing temperature differences.We found that shorter blooming lengths occurred when maximum temperatures averaged between 13.5–14.5 ºC 30 days prior to blooming when examining the relation between blooming length and maximum temperature. If the average of maximum temperatures was below 13 ºC or exceeded 15 ºC during this period, then we could calculate with a blooming period longer than ten days. We proved that little precipitation and high temperature accelerates physiological processes, therefore we could calculate with an accelerated blooming and shorter blooming period.
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New sour cherry cultivars selected from local sources
79-80.Views:286New sour cherry cultivars selected from local sources
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Effects of different pollination treatments in genotypes of Prunus salicina Lindl.
141-146.Views:123The low productivity in the Japanese plum (Prunus salicina Lindl) is related with self-incompatibility characteristics, so other species or varieties that act as pollinators need to be present to improve fruit production. The objective of this work was to study the efficiency of pollination in different genotypes of P. salicina using treatments of natural self-pollination, cross-pollination with P. armeniaca cv. Giada and open pollination. These treatments were evaluated through viability techniques and in vitro and in vivo germination of pollen grains; the growth of pollen tubes along the pistil was also observed. Genotypes used in this study showed differences for each one of the pollination treatments. Some genotypes showed signs of self-sterility and interincompatibility with P. armeniaca cv. Giada, while others showed partial self-fertility characteristics or pseudocompatibility. Moreover, some genotypes showed a higher affinity coefficient with cv. Giada and these will be indicating a possible intercompatibility. These studies will be an important contribution breeding and selection of intra and intercompatible genotypes to be used in commercial orchards.
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Influence of irrigation and row spacing on the growth, seed yield and active substance of milk thistle (Silybum marianum)
78-81.Views:203Milk thistle (Silybum marianum (L.) Gaertn) has been used in medicine since ancient times, but it has been cultivated as a medicinal plant only in recent decades. The ripe fruit of milk thistle contains flavonoids, which are used to prepare anti-hepatotoxic drugs. The main purpose of this study was to substantiate the effects of irrigation and row spacing on growth, seed yield and the content of active substances (silybin and silymarin) in milk thistle. The results showed that the suitable amount of irrigation was 20 mm and the appropriate row spacing was 25 cm.
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Nectar production of pear (Pyrus communis L.) cultivars
67-75.Views:278Detailed studies were made on the nectar production of 44, 16 and 18 pear cultivars, respectively, in a cultivar collection of pear during three consecutive years with highly different weather in the blooming. Results clearly show that pear does not necessarily produce small amount of nectar as stated in the world literature. In fact, pear can produce extremely high amount of nectar sometimes much higher than other temperate zone fruit trees species but its nectar production is highly subjected to weather, first of all to air temperature. Low nectar production seems to be more frequent than high one and cold weather can prevent its nectar production at all. On the other hand, results corroborate to the earlier statements on the low sugar concentration of pear nectar. There is a highly significant negative correlation between the amount of nectar produced by pear flowers and its sugar concentration (r = -0.52, n = 291, p< 0.001 for 1996, r = -0.34, n = 197, p< 0.001 for 1998). Sugar concentration in individual flowers may be up, to 40% in exceptional cases but generally it is well below 20%. Very high figures for sugar concentration in pear nectar at the literature seem to be incomprehensible. In contrast of some earlier statement in the literature no real difference could be established in the nectar production of pear cultivars, based on much more measurements than in earlier studies. Very low sugar concentration in pear nectar can explain the fact that the overwhelming majority of honeybees are pollen gatherers at pear trees even in the case of exceptionally high nectar production.