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Susceptibility of some traditional pear cultivars of Hungarian and foreign origin to the pathogenic bacterium Erwinia amylovora
41-45.Views:292Fire blight, a disease caused by the bacterium Erwinia amylovora (Burrill) Winslow et al., has been causing serious damage in Hungarian pear plantations since 1996. A prospective control measure could be the use of resistant cultivars. For that purpose ten pear cultivars have been tested under laboratory and greenhouse conditions for resistance to Erwinia amylovora strains collected in Hungary. Six of these cultivars are Hungarian ones of unknown origin, while four are traditional old varieties. Resistant cultivars should serve as germplasm for future breeding. Inoculations were made with a mixture of different pear isolates of the bacteria collected from various growing regions of Hungary (Ea 21, 23), at a density of 5x108 cells/ml. Susceptibility/resistance has been assessed on the basis of intensity of blight symptoms observed on shoots, flower parts and fruits. Cultivars were assigned to three susceptibility groups (low, moderate and high). Complete resistance was not found among the cultivars tested. The highest level of resistance was found in cultivar 'Kieffer', while the other cultivars displayed either moderate or high susceptibility to infection.
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Extending the vase life of Solidago canadensis cut flowers by using different chemical treatments
83-86.Views:319In order to increase the vase life as well as quality of leaves of goldenrod (Solidago canadesis), the effect of 8-hydroxyquinoline sulphate (8-HQS), silver thiosulphate (STS) and l-methylcyclopropene (l-MCP) were investigated. 8-HQS was used as a continuous treatment at 400 ppm with or without sucrose at 50 g/l. The treatment of STS was used by putting the flower bases at 0.4 mM for 6h with or without sucrose at 50 g/l. l -MCP was used at 0.5 g/m3 for 6h dry or in water. Except the treatment of l -MCP in water, the chemical treatments, which were used, led to the increase vase of life of leaves as well as to the inflorescence of cut solidago spikes compared to the control. The best treatment in this concern was 8-HQS at 400 ppm without sucrose, which resulted in longest vase life of leaves as well as inflorescences and lowest percent loss of fresh weight of initial.
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Effect of Foliar Nutrition on Post-Harvest of Onion Seed under Sandy Soil and Saline Irrigation Water Conditions
85-92Views:420Foliar application has been determined to be an effective nutrients delivery strategy in vegetable and fruits. The enhancement of vegetable and fruit yields affected by foliar nutrients application has been recognized in previously conducted studies with perennial tree crops. The efficiency of foliar nutrition is dependent on soil, climate, fertilizer and the amount of nitrogen used. There is no sufficient information concerning cooperation of foliar nutrition with all nutrients form as well as the rates of these nutrients fertilization in vegetable
and fruit crops. Two successive winter seasons of 2008/2009 and 2009/2010 were conducted under sandy soil conditions to study the effect of spraying with 12 commercial compounds on inflorescences diameter, flower stalk length, number of seed stem /plant, weight of 1000 seed, germination percentage, seed yield, moisture content, catalase , peroxidase activity and malondialdehyde content of onion seeds. The plants
sprayed with union Zn, union Mn, union feer, shams k, elga 600, boron, and amino x had the highest vegetative growth parameter, germination percent and enzyme activity. The plants sprayed with union Zn, union feer, shams K, magnesium, caboron, hummer and amino X had the highest seed yield ha-1. The seeds were stored for one year to study the effect of different commercial compounds and storage temperatures on germination, moisture content and change in antioxidant enzymes activities of onion seeds during the storage period. Storage at cold temperature showed higher germination percent, moisture content and lower malondialdehyde content than storage at room temperature. The treatment with union Zn, union feer, union Mn, boron, elga 600, caboron, amica, hummer and amino x had the highest germination percent. -
Fruit drop: I. Specific characteristics and varietal properties of fruit drop
59-67.Views:15218The basic conditions of fruit set (synchronic bloom, transfer of pollen, etc.) still do decide definitely the fate of the flower in spite of the best weather conditions. 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. This study discuss this physiological process based on the international specific literature. 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.
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Sugar composition of floral nectar in sour cherry cultivars
109-113.Views:437The composition of floral nectar in sour cherry cultivars studied in 1997 at Újfehértó was in agreement with our previous data, the three most frequent sugar components being glucose, fructose and sucrose. Nectar secreted at night is generally more diluted than nectar produced during the day. None of the nectar samples produced at night reached the threshold value (100 mg/ml) of bee visitation. In the majority of cultivars the difference in concentration between night and day nectar is not too high, but in two cultivars, 'Korai pipacs' and ‘Újfehértói fürtös’ the difference is quite significant. Most sucrose was found in the nectar of cvs. 'Érdi jubileum' and ‘Újfehértói fürtös’, but a high amount of sucrose was measured also in the flowers of 'Korai pipacs' and 'Meteor USA'. Nectar concentration varies from opening of the flower to petal fall to a smaller or greater degree, depending on the given cultivar. From the 9 sour cherry cultivars studied ‘Újfehértói fürtös’ and Tandy 48' had the most attractive nectar for bees. There was no correlation between nectar composition and free fertilisation. On the basis of nectar composition the majority of the sour cherry cultivars studied can be classified into the sucrose-rich category; only one cultivar, 'Érdi jubileum' had a sucrose-dominant secretory product. The composition of nectar in the studied sour cherry cultivars is preferred by bees.
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Effect of life cycle on the production of mullein (Verbascum phlomoides L.)
123-125.Views:282Aim of the present investigations was the optimalization of the production of the annual cultivar `Napfény' of Verlxiscum phlomoides L. Quantitative data on morphology (growth, leaf and flower size, branching) yield and content of active materials (mucilages, flavonoids) were studied at six sowing times.
We established, that sowing time may be one basic factor in the production of the annual variety. The major yield was obtained by sowing either late autumn (end of October) or early spring (middle March). At these plots the fresh mass of the flowers was 257-288 g/plant, the drug mass 28-29 g/plant, by 45-70% more than that of the mean of other treatments.
It was established, that under optimal cultivation conditions the annual form of mullein may reach higher individual yields than the plants of the indigenous wild growing population.
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Comparative analysis of sweet cherry cultivars on their ecological and biological indicators
14-33.Views:335Sweet cherries are slightly more demanding than sour cherries. It is grown in warmer areas around the world. The relative ecological values obtained for the varieties obtained by extensive data collection differ slightly from the leading descriptions. Warm and demanding. The woody parts tolerate the cool of the winter quite well, the flower buds are damaged by the spring frosts. Its water demand is medium, in the case of 550 mm of annual rainfall, it adorns well on loose soils with good nutrient supply. Airy ground, neutral soil (pH 5.5-7.5) is optimal, but not suitable for areas with strongly calcareous, stagnant, stagnant groundwater. From the start of ripening, sudden rainfall, stormy winds and birds can cause great damage. Highlighting the world’s leading varieties in the study (Bing, Rainier, Chelan, Van and Burlat) (Iezzoni et al., 1991, Faust & Surányi, 1997) - according to relative ecological and biological values, the most popular cherries are mainly they differed from the other varieties based on TB and KB. Open pollination and with it, the productivity of the varieties exceeded the overall variety average precisely because of the breeding objectives. Certainly, the analysis of historical varieties, the oldest landscape and local varieties based on relative ecological and biological values can help further pomological-ecological research.
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Growing greenhouse cut flower in hydro-culture
37-39.Views:286The importance of hydro-cultural growing is significantly increasing.We have been dealing with the hydro-cultural growing of cut flowers at the Department of Ornamental Plant Growing and Maintenance of Gardens at the College Faculty of Horticulture at Kecskemét College since 1988.We started our experiments by growing carnation in growing establishment without soil then we introduced other species of cut flowers and potted ornamental plants into our research work.
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Scheduling of ornamental plant production
76-86.Views:281The production of ornamental plants represents an important branch of our horticulture. The growing area is relatively small (round 2800 ha), the production value, however, a rather large. Notwithstanding, its financial balance is inactive because the demand surpasses the supply copiously.
The most popular plants are as follows: carnation, gerbera, rose, bulbous flowers, chrysanthemum, other cutflowers, cutgreens and Gypsophyla — their total production value makes up to Ft 8-9 billion. The area of ornamental nurseries — about 800-900 ha — is to be found mostly on the western part of our country.
Our accession to the EU will have undoubtedly an impact on our ornamental plant production. We must take into account, that in greenhouse production the specialization extends all over the world, field production over a limited region. Our chances will not deteriorate by joining the EU. The buyer — chiefly because of ecological purposes — will prefer the domestic product to the foreign one. By the way, our products will be competitive, as far as quality or price is concerned, with those of western Europe. Last but not least, we may hope a greater saleability of home-bred, special varieties and cultivars, the so-called "hungaricums", both in the domestic as well as export markets. It is anticipated that we will have a good turnover with potted ornamental plants and flower seedlings. Our nursery products will become marketable too.
To exploit the opportunity, of course, the necessary conditions are to be created. First of all, we need development in research, with special regard to breeding, at the same time in education, in extension service, in the training of experts, on a high level. Some tasks can be solved, no doubt by improvement of the organisation within the branch. At the same time the state subsidy is indispensable in order to promote both the technical and the research activities. State subsidy is also necessary to build up more advantageous conditions of sales like in some foreign countries (e.g. the Netherlands).
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Nutrient demand of stone fruits
19-23.Views:258Effects of nitrogen, phosphorus and potassium fertilization were investigated on the change of nutrient content, vegetative and generative production of apricot, peach and sour cherry trees, as well as on frost hardiness in long term experiments. Nitrogen and phosphorus fertilization increased only the concentration of these elements in cherry leaves without effect on growth and yield. Consequent potassium effect was proved on these stone fruit species. Effect on yield appeared following the first higher crop load.
Potassium supply has positive effect on frost hardiness of apricot and sour cherry flowers and peach flower buds.
In peach, the lime content of soil decreased the yield but it could be compensated by potassium dressing to some extent. Favourable nutrient boundary values were determined for soil and foliage.
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Comparison of honeybee behaviour in blooming fruit plantations
147-151.Views:1064Field observations were made on the fl ower visiting behaviour of honeybee foragers in commercial fruit plantations of apricot, Japanese plums, sour cherry, apple and pear. The number of inspected cultivars was 18. The intensity of fl ower visiting by honey bees was markedly different when data of different fruit species are compared. Most intense bee activity was registered on the Japanese plums, somewhat less on apricots, the intensity diminished signifi cantly with apples and pears. Our data presented on the honeybee visitation of Japanese plums can be regarded as new fi nding because no information has been available so far on the relative attractiveness of this fruit species compared to European fruit tree species. Japanese plums were somewhat more attractive to honeybees than apricot and much more attractive than sour cherry, apple and pear. The behaviour of honeybees as visiting the blooming trees displayed specifi c differences according to the fruit species (apricot, sour cherry, pear), which coincide largely with earlier results. It is notable that the fl ower visiting behaviour of honeybees on Japanese plums has been found to be fairly similar to the same on European plums.
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The effect of the limitation of insect pollination period on the fruit set and yield of quince cultivars (Cydonia oblonga Mill.)
103-108.Views:756The effect of the partial and/or complete limitation of the insect (bee) pollination period was studied in three consecutive years at 6 quince cultivars. Quince is greatly sensitive to the limitation. Complete limitation of insect pollination resulted in no yield and also a partial limitation of the insect pollination period (exclusion of the bees at the first or at the second half of the blooming) depressed the final set and the yield by 60-70% at least or more, sometimes down to no yield. No real correlation was found between the mean mass of fruits and the fruit set. The mass of fruit seems to be rather a character of the cultivars. A loose but significant correlation was established between the intensity of honeybee visitation and the consequent yield of quince. As much as some 4-5 and 8-10 honeybee visits are needed a day on one flower to achieve the required optimal fruit set that has been declared to be 20-25% for quince in the literature. These are extremely high bee visitation figures, accordingly, no doubt the commercial quince plantations require much higher number of honeybee colonies than other temperate zone fruit tree species to supplementary pollination
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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:945We 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. -
Changes in Some Quality Criteria During Controlled Atmosphere (CA) Storage of Peaches
58-61.Views:221Intensive research has been implemented on different aspects of the bee pollination of pear in Hungary in the past decade, extending to the following topics: the effect of the opening sequence of the flowers within the inflorescence of pear cultivars on the effectiveness of bee pollination; the nectar production of flowers of pear cultivars; intensity of honeybee visitation and their foraging behaviour at the flowers of pear cultivars; flower constancy of honeybees to pear plantations; competition by weeds in bloom for bee pollination in flowering pear orchards; and some aspects to the bee pollination strategies of pear plantations (the effect of the limitation of bee pollination period on the set and the yield, possible compensation of frost damage of flowers by bee pollination in pear orchards, the optimal size of single cultivar block in pear plantations). The results of these studies are reviewed in this paper and some important aspects that need further studies are outlined.
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Inheritance of blooming time in walnut, with regard to the property of reproductional autoregulation of species
118-122.Views:225A great number of crosses have been made with Hungarian and foreign varieties as partners to breed improved varieties. This species shows a particular trait, namely the autoregulation of fruit set, which affects considerably the productivity of commercial orchards. Thus the inheritance of the blooming time of the male and female flowers has been explored for several years in the progenies.
It has been stated that
- the feature of the partners does not turn up predictably in the progeny,
- it is most important to take into consideration the blooming time class of both, male and female flowers in planning associations of varieties for commercial orchards.
- in years of irregular spring weather the stability of the blooming time of the variety or in other words the deviation of the actual blooming time of variety from its characteristic blooming-time class is also very important.
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Influence of foliar nutrition on apple production
15-18.Views:253On the basis of different experiments the technology of intensive foliar nutrition was studied in apple orchards in the period from 1996 until 2000. Yearly apple nutrition programs based on soil analyses. The foliar nutrition program was prepared in accordance with the soil, fruit analyses and climatic conditions. If needed, certain improvements were made according to the analyses of leaves and precipitation in the current year. The richness of the soil and ratios between individual nutrients gradually improved. The foliar nutrition influenced the yield quantity, quality and flower bud differentiation. The yield was doubled and the mean of five years reached 70 tons per hectare. In spite of high yields there were no problems with alternative bearing. The analyses of soluble solids, firmness, fructose, glucose, sucrose, malic acid, citric acid in the fruits and mineral soil composition indicated that the produced fruits were of high quality despite greater yields.
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Effect of hail protecting nets on the quality of apples
77-80.Views:1039Today, 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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Seasonality of weather and phenology of reproductive organs of flower of sour cherry cultivars in Hungarian climatic conditions
75-80.Views:820Sour cherry (Prunus cerasus L.) is one of the most important fruit crop grown in Hungary, The flowering phenology and pollen shedding/stigma viability ratio, in an effort to elucidate the reproductive phenology of nine economically important sour cherry cultivars (Érdi bőtermő, Debreceni bőtermő, Csengődi, Kántorjánosi 3. Pándy 279. Úfehértói fürtös, Petri, Éva, and Oblacsinszka) all widespread in the Hungary, was studied at Újfehertó climatic condition. The main aims were to investigate how possible environmental cues influence timing and development of phenophases and whether different cultivars have different seasonal responses to these cues. Likely effects of climatic changes on phenological development patterns were also considered. Our results revealed important aspects of the reproductive biology of sour cherry flowers. The amplitude of the phenophase "beginning of blossoming" between cultivars did not exceed 6 days. There is maximum 3 days difference in blooming length of different direction in each cultivar. Pándy 279 showed high variability when the position of flowers changed on the tree shoots. Újfehértói fürtös was stable in all four directions of tree. The pollen shedding period and stigma viability ratio was well synchronous. Pollen shedding phenomenon occurred in the range limitation of secretary activity of stigmas in all five cultivars. Distribution of pollen shedding over the secretary activity of stigmas is almost good. In all five cultivars maximum pollen shedding occurred about the high temperature part of the day.
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Incompatibility studies of Hungarian sweet cherry (Prunus avium L.) cultivars by traditional test crossings
43-47.Views:222Cross-incompatibility is a common phenomenon between various sweet cherry (Prunus avium L.) cultivars. Traditionally, choosing cross-compatible cultivar pairs is based on test crossings in the field.
There is a lack of information about fertility relations of novel Hungarian sweet cherry cultivars and selections. We have studied cross-incompatibility in 42 sweet cherry cultivar pairs by test-crossings in the field. Out of those, 3 combinations showed incompatibility and 15 pairs were compatible.
Test-crossing results proved that with the knowledge of S-allele constitution of Hungarian cultivars incompatible cultivar pairs are recognised in practice reliably. However, we assume that in sterility not only the S-gene system, but other factors (e.g. abnormal development of pollen or flower) also occur, therefore, their examination would be needed.
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Prolonging the vase life of cut Carnation 'GIOKO' by using different chemicals
65-68.Views:387Cut flowers of Dianthus caryophyllus L. cv. GIOKO were treated with different concentrations of sucrose and in combination with 1methylcyclopropene (1-MCP) to compare the effect of these treatments with floral preservative (`Spring') on the longevity of flowers. Distilled water was used for preparing all solutions. The control flowers were held in distilled water. Clorox at 2 mL- I was added to all treatments containing sucrose and it was also applied as a separate treatment. The vase life of cut carnations was significantly prolonged due to the use of chemical treatments, as compared to the untreated control. The longest vase life (18.33 days) was obtained by using 1-MCP 0.5 g m-3 for 6 h treatment. All concentrations of sucrose had a positive effect on flower diameter. The best treatment in this respect was 1 -MCP with 30 gL-I sucrose. 1-MCP treatment significantly increased the chlorophyll content, as compared to the control or the "Spring" treatment. The highest values in this respect were obtained by 1 -MCP treatment alone or with the lowest level of sucrose. The effect of these treatments on the pH of solutions is discussed.
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Detemination of the time of pruning regarding the ability of developing flower buds and their frost tolerance in sweet cherry varieties
45-48.Views:303In sweet cherry growing, intense technology is introduced as the up to date development. Among the elements of the technology are the choice of variety, planting design and pruning are the main elements. The methods, intensity and the timing of pruning are largely dependent from the growing habits of the varieties, the light demand of the parts of different age and their tendency of getting bald on the aging zones. One of the main limiting factors of production, the frost damages are outstanding. In choosing the site of plantation, we must avoid the places, where spring frosts used to occur, the next moment is the role of the variety and the technology applied. In Hungary, the late or spring frosts are considered, however, the winter frosts may also cause heavy losses, which depend also on the health and nutritional condition of the trees when being exposed to temperature minima. Our present study is based on a 9-year-old plantation trained to slender spindle as well as to free spindle crown. We observed the development of fruiting structures and their frost damage also in relation with the timing of the pruning operations during the winter or summer, and compared also the varieties with each other.
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Field trials with non-bactericide products to control fire blight in apple orchards
55-60.Views:252Recently, novel strategies and chemical agents for prophylactic protection against the bacterial (Erwinia amylovora) disease fire blight are being sought. Resistance-inducing compounds, such as prohexadione-Ca represent promising alternatives. Prohexadione-Ca is the active ingredient of the bioregulator Regalis, currently being introduced in several European countries and overseas. Another product used in this study was Biomit Plussz, a leaf fertiliser providing harmonic supply of nutrient elements, the complete supply is assumed to improve the tolerance against diseases.
Treatments' effects of both of these products were compared to the effectiveness of treatments with antibiotics repeated twice, three or four times a season.
In the years of 2001 and 2002, the effectiveness of both Regalis and Biomit Plussz in reduction of incidence of shoot blight was similar, or proved to be superior to the check treatments consisting of repeated sprayings of antibiotics. Last year (2003) treatments of streptomycin resulted — although within the same magnitude — in a somewhat better control of shoot blight than sprayings with the other compounds.
As regards severity of blossom blight, inconsistent results were recorded concerning both Regalis and Biomit Plussz.
In general, prohexadione-Ca is less efficient for controlling flower infection by E. amylovora as compared to shoot infections, since successful prophylactic treatments are difficult to carry out early in the season. The highest effectiveness in fire blight management can, therefore, be achieved by using prohexadione-Ca (as preventive protection) in combination with streptomycin or other suitable antibiotics (as curative protection).
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Floral attractivity of pear cultivar 'Cinderi'
102-109.Views:406The regularities of primary attractivity have been studied at the pear cultivar `Cinderi' for two years. Nectar quickly evaporates from the totally open nectary surface of pear flowers exposed to environmental effects, and the rhythmicity of nectar secretion can be determined with difficulty. Flowers do not function according to a unified endogenous rhythm, the whole tree becomes continuously attractive for insects, since it attracts insects on more occasions during the day with some of its flowers. During the warm afternoon hours there is usually no measurable nectar production. Pollen shedding is most intensive in the afternoon hours. Pear flowers produce little and diluted nectar, which often does not come up to apicultural expectations. The age of the flower does not significantly affect the quantity and refraction of nectar. The flowers of pear cv. ‘Cinderi' are delayed homogamous.
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Fruit drop: The role of inner agents and environmental factors in the drop of flowers and fruits
13-23.Views:1322The 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.
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Reactions of different plant organs of pear cultivars to Erwinia amylovora infection
17-21.Views:313Research project has been initiated in 1999 with the aim of evaluating the degree of susceptibility/resistance of pear cultivars grown in Hungary to fire blight disease caused by Erwinia amylovora. The recently selected promising cultivars were also examined. Inoculation experiments were conducted in controlled greenhouse conditions because of quarantine regulations in Hungary. Following the disease process, development of symptoms of plant organs (shoots, flower parts, fruits) was observed. Suspension of two E. amylovora strains (Ea 21, Ea 23) isolated from pear was used in a mixture (5x108 cells x m1-1) for the inoculation. Twenty-six pear cultivars were examined and grouped into four categories: low susceptibility, moderately susceptible, susceptible and very susceptible. Most of the cultivars were susceptible or very susceptible while some promising 'Eldorado', 'Harrow Delight' and `Hosui' showed low susceptibility.
