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Microsporogenesis of peach (Prunus persica L. Batsch) varieties
7-10.Views:281Bud dormancy during winter is a critical factor in peach production in Hungary. The yield is determined basically by the survival rate of flower buds during winter frosts and by their ability to develop normal floral organs. It is important to investigate the genetic basis of slow floral development during dormancy for the purpose of breeding peach varieties with better winter hardiness. The aim of the present research was to examine microsporogenesis in 14 peach varieties during three successive winters in a Hungarian germplasm collection and to study the effectiveness of this method in variety evaluation. There were significant differences in the dynamics of microsporogenesis both between the varieties and between the years. Of the varieties, ‘Mayfire', bred in California, possessed the quickest pollen development rate. The microsporogenesis of `Piroska', a Hungarian local variety, was the slowest. Rapid floral bud development was observed in `Aranycsillag', `Springcrest' and 'Venus'. A medium developmental rate was characteristic of `Babygold 6', Fairlane', `Michelini' and `Red June', while development was slow in 'Champion', 'Early Redhaven', `Redhaven', `Harko' and `Mariska'. Based on these results, the study of microsporogenesis represents a reliable method for the phenological description of peach varieties during dormancy. The application of this method makes it possible to identify varieties and landraces with slow flower bud development, suggesting better winter hardiness.
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Effect of Fertileader® Vital on green pea maturation
57-59.Views:232The changes of tenderness of three green pea varieties with different maturity were studied after Fertileader® Vital fertilizer treatment. The fertilizer treatment caused signifi cant differences in the tenderness of treated plants in every year. After the second measuring time; the treated plants showed better quality than the control ones. The treated varieties kept their tenderness longer due to this foliar fertilizer, the yield have better quality so even better suited to the requirement of canning industry. Use of Fertileader® Vital is of an economic importance because high economic benefi t can be realized in one hectare after Fertileader® Vital treatment. By using this foliar fertilizer 12,840 HUF extra profi ts can be realized by producing green peas of I. quality class instead of yield with II. quality category. This extra profit could increase to 447,840 HUF considering that green peas belong still to the II. quality class after fertilizer treatment when the quality of non-treated plants are no more suitable for the canning industry.
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Powdery mildew infection dependent on weather factors in vineyards near Keszthely in 2008
55-59.Views:229Weather 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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Morphological examination of Hungarian apricot rootstock varieties
59-63.Views:273Apricot seedlings are one of the most widely used rootstocks in apricot growing of Hungary. The National List of Hungary contains 7 apricot seedling rootstocks varieties. The production of apricot graft on seedling rootstock takes 3 years from the seed production to the complete graft and requires more space. It is important to provide the trueness to variety name during this process. In the genus Prunoideae not only the plant but also the stone should have typical characteristics. It seems to be useful to examine the morphology of stone. The observed varieties were 'Tengeribarack C.1300', 'Tengeribarack C.1301', 'Tengeribarack C.1650', 'Tengeribarack' C.1652', 'Tengeribarack C.145', 'Tengeribarack C.1426' and 'Tengeribarack C.2546`.1t seems to be the most suitable characteristic to make a distinction between these varieties by stone, the ratio height of stone to lateral width of stone, the ratio of height of stone to ventral width of stone, the ratio of lateral width of stone to ventral width of stone and the ratio of ventral zone to ventral width. From not measured characteristic seems to be most utilizable to make distinction: the fusion of dorsal groove margins, the shape of apex, the presence of a mucro of the apex, the shape of stalk end in lateral view and the texture of lateral surfaces.
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Fruit production and research in Hungary - An overview
7-11.Views:534Hungary is traditionally a food producer country. 63% of its total land area can be cultivated. Horticulture is one of the fundamental agricultural branches. The country has a moderate continental climate, with a mean temperature of 10 °C. The average hours of sunshine ranges 1,700 to 2,100 hours. Under the geographical condition in the Carpathian Basin the chemical composition of the fruits has a good harmony. The total fruit acreage is 97,000 ha with a crop of 800,000 to 900,000 tons yearly. In 1982 1,934,000 tons of fruit crop were produced since then it has decreased. The most important fruits are apple, European plum, sour cherry and raspberry. The percentage of apple reaches almost up to 60%. In the new plantings sour cherry, apple and black elderberry is popular. The most important fruit-producing region is situated at the North-eastern part of the country. More than 40% of Hungary's fruit production is concentrated there. In ranking the 2nd place is taken by fruit growing area in the middle of Hungary, where the production of stone fruits and small fruits has a considerable proportion.
In the 70s and 80s of last century there was a developed research structure and wide range of research activity in Hungary. From that time the research capacity has considerably decreased first of all in the field of technological development. The main research area is fruit breeding and variety evaluation.
Fruit scientists and fruit grower specialists are held together by the Hungarian. Society for Horticultural Sciences which has a membership in ISHS. Fruit researches and scientists having academic degree are belonged to the Horticultural Board of Hungarian Academy of Sciences.
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Farm economic evaluation of elderberry production
57-60.Views:269In this present study the efficiency as well as the farm economic advantages and disadvantages of elderberry production are examined. Our objective is to determine the fact that under what conditions the elderberry production may be profitable regarding the present economic and market situations. Our analysis was carried out by a simulation model based on a farm-level data gathering in production enterprises. The total investment cost of an up-to-date, elderberry orchard of traditionally cultivated without irrigation is between 1000 to 1700 thousand HUF per one hectare and turning to productivity is expected within 4-5th years. These orchards are able to produce yields of 8,0 to 9,0 tons per one hectare in the average of the productive years, which makes reaching a revenue of 800 to 1000 thousand HUF possible regarding a per kg average selling price of 80 to 110 HUF. By this a net profit of 200 to 400 thousand HUF may be realized in case of a per hectare production cost of 600 to 700 thousand HUF. At the end of the lifetime of the orchard (12-15th year) an internal rate of return of 10 to 4%, an NPV of 1500 to 2000 thousand HUF per one hectare are typical in an average case, and the payback may be expected in the 6th to 8th year. From the farm economic aspect the elderberry may be considered as an extensive sector, which advantages are low capital and labour need, early recovery, good-acceptable profit on capital and cost to profit ratios, but its disadvantage is low per hectare profit comparing to intensive fruit species and orchards. In this way in general farms of capital-extensive and avoiding risks choose elderberry production.
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Effects of different rootstocks on the morphologic parameters of watermelon grafts during transplant production
69-73.Views:181Before Hungary joined the EU watermelon production was a key sector of the Hungarian vegetable industry. Its production area shrank by nearly 60 % since 2004, it is only 5000 ha today. Stable and reliable market failed to evolve in the last years and extreme weather events occurred more frequently. An unfavourable growing season can notably affect the production volume of the next season. Information gathered in the last years support the assumption, that suitable stocks can help eliminate the issues caused by extreme weather or short-term crop rotation. Choosing the right grafted or non-grafted transplant is not enough any more, growers also have to select stock. In fruit and vine production choosing the stock, which is the most suitable for the technology is evident and this approach should be widely adapted by watermelon growers as well. In this research we investigated the growth parameters of different watermelon stocks and their effect on the scion during the transplant production. Measurements were carried out on seven different stock-scion combinations of the scion ’Topgun F1’ hybrid. Two of the stocks were interspecific (Cucurbita maxima × Cucurbita moschata) and five stocks were Lagenaria-type (Lagenaria siceraria) stocks. We made and recorded observations of the transplants’ length (cm), diameter of the stock and scion (mm), number of leaves (piece), root length (cm), root mass (g) and shoot mass (g). We concluded that early pricking out of transplants with interspecific stocks is successful due to their hardiness and vigorous growth. The effect of the ’Shintosa camelforce F1’ interspecific stock was outstanding. Furthermore, the results confirmed the practical observation that the root system of interspecific stocks grow vertically more allowing them to take up water and nutrients from lower soil layers in poor sandy soils. From the Lagenaria group the root system of the ’DG-01 F1’ was similar to the interspecific stocks’. It can be grown even in sandy soil, however other Lagenaria-type stocks are more suitable for production in hard soils with nutrient supply because of their compact root system. This study can serve as a basis for further research in the topic that can conduce to site- and technology-specific stock selection.
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Pál Maliga, founder of the research in floral biology of fruit species in Hungary
57-60.Views:266Pál Maliga founded the Hungarian research in floral biology of fruit species during his more than forty-year-long carrier. Almost all pome and stone fruit species have been covered by his activities, but he also dealt with the fertility of walnut and chestnut. Regularities have been revealed and the methodical studies opened the way to approach and elaborate alternatives for the association of varieties in planning high yielding commercial plantations. In his breeding activity the choice of crossing parental varieties was based on the knowledge in fertility relations. The obtained sour cherry varieties represent the world-wide maximum quality, reliability and security of yields. Hungarian renewed sour cherry cultivation owes its fame and prosperity to those varieties, nevertheless also to the radical knowledge of the biological bases of fertility.
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Mechanical and physical control in apple orchards as preventative fungal disease management
19-21.Views:297In this minreview, mechanical and physical control against apple fungal diseases among non-chemical control approaches were summarized. This overview listed five groups of mechanical and physical control methods: pruning, removal of inoculum sources, shredding of leaf litter, burying of inoculum sources and flaming of leaf litter. These methods were shown to reduce succesfully infection potential of inoculum sources in orchards and these non-chemical control measures are one of the most essential approaches for preventative fungal disease management. However, most of these methods are not widely spread in the apple-growing practice due to relatively low control efficacy, medium to high labour costs and/or time limits during the season.
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Cytokinins affect the stomatal conductance and CO2 exchange of in vitro apple leaves
25-28.Views:277Effects of different cytokinin supplies including two types of aromatic cytokinins, such as benzyl-adenine, and 3-hydroxybenzyladenine applied at two different concentrations (2.0 and 6.0 μM) were studied on water and gas exchange parameters in in vitro apple leaves of ‘Royal Gala’ and ‘Freedom’ scions after 3 weeks of culture. Cytokinin supply affected the stomatal conductance of water vapour, transpiration rate and the sub-stomatal CO2 concentration of leaves. Effect of cytokinin depended on its applied type and concentration, moreover on the apple scion. According to the results, the rate of CO2 exchange itself is not usable for characterization of function of photosynthetic apparatus of in vitro leaves. However, measurements of stomatal conductance of water vapour and transpiration rate seemed to be good indicators for stomatal behaviour of in vitro apple leaves.
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Conditions of rentability in the apricot industry of Hungary
127-129.Views:186Total investment costs of an up to date apricot plantation requires about 5000 thousand HUF/ha. Modern
plantations yield under normal conditions 15–20 t/ha with 80% quality for fresh consumption. Consequently, taking the life span of a plantation (15 years), the internal rate of return of 15–17% per year (IRR), that means that the costs of investment will be regained in the 9–10th year, which is considered to be satisfactory. However, weather hazards (frost, hail) may occur at a probability of 20–25%, therefore, maintaining the quality (80% for fresh consumption) and yields (15–20 t/ha) are badly needed to speak about rentability. This level of yields maintains the option of feasibility up to 20–25% losses. -
Yielding capacity and regeneration of different ages fruit-bearing shoots in sour cherry
55-57.Views:187The yielding potential and regeneration (i.e. germination of hidden buds) after pruning of the fruit-bearing shoots of different ages were compared in sour cherry cultivars pruned to spindle shape. The examinations were carried out in order to determine the optimal pruning strategy resulting in the highest long-term yielding of sour cherry cultivars with intensive crown shape (free and thin spindle shape). According to our results, there are great differences among the studied self-fertile sour cherry cultivars in yielding and regeneration, which are worthwhile to be considered in determining the method and degree of pruning.
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Analyses of temporal dynamics of brown rot development on fruit in organic apple production
97-100.Views:200In a two-year study, yield loss and temporal dynamics of brown rot development caused by Monilinia fructigena (Aderh. & Ruhl.) Honey were quantified and analysed in two organic apple orchards (Debrecen—Pallag and Debrecen—Józsa). The first infected fruits were observed at the beginning of August in both years and both locations, except for one occasion when the first infected fruit was found at the end of July. Temporal disease development was continuous up to harvest time in both years and locations. In the two years, pre-harvest yield loss on the trees amounted between 8.9% and 9.3% at Debrecen-Pallag and between 9.7% and 10.8% at Debrecen—Jozsa by fruit harvest. Incidence of infected fruits on the orchard floor ranged from 32.4% to 43.2% and from 53.3% to 61.9%, at Debrecen—Pallag and Debrecen—Józsa, respectively, by fruit harvest. Analyses of temporal disease progress showed that the best-fitted mathematical function was the power function in both orchards and years. Both parameters of the power function clearly demonstrated that incidence of brown rot on fruit increased faster on the orchard floor than on the tree. Moreover, the disease increase was faster at Debrecen—Józsa in most cases than at Debrecen—Pallag. Our results indicated that the strategy of disease management, the ripeness of the fruit and the presence of a wounding agent played an important role in the yield loss and in the temporal development of fruit disease incidence caused by M. fructigena in organic apple orchards. Biological and practical implications of the results are discussed.
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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:310The 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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Selection of the chance seedlings of `Mézes körte' (Pyrus communis L.) from the gene bank of Keszthely
21-27.Views:259We have concluded the selection tests of the `Mézes körte' seedlings planted in the spring of 2006, with special emphasis on the cotyledonary, foliage leaf and the height of plant. Out of the 75 seeds planted in rows, there were 40-45 pieces growing out, so during the first cotyledonary test we had to calculate with almost 40% decay. On 12th April 2006, we recorded some of the important characteristics of the seedlings in their cotyledonary stage which characteristics were important from the point of view of selection (cotyledonary form, cotyledonary length, cotyledonary thickness, cotyledonary colour, cotyledonary petiole length, cotyledonary petiole thickness, cotyledonary petiole colour). The above morphological characteristics are shown in Table No. 1-6. We have also tested the seedling in foliage leaf state, paying special attention on the development stage of the plants (colour of foliage leaf , height of plant). We have completed statistical calculations of the two above mentioned characteristics. The result of that is summarised in Table No. 8-9. The variation coefficient show smaller value in the case of the foliage leaf number (15-32%), while the wider range of spread of the data referring to the height of the plant is shown by the 33-61% CV values. On charts No 4-9. we present the relationship between the height of the plant and the number of foliage leaf, as well as the differences between the two graphs. Based on the above charts and graphs it can be defined that the 40% destruction of the developing seedlings during the period till the next measurement reached 70-80% level. In spite of this however some seedlings showed strong and balanced growth (A44, B42, C25, D16, E5, E39, F38), the further testing and selection of those is to be completed in the future.
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The size of the canopy of sour cherry trees depends on the time of pruning
49-52.Views:175The intensive culture of sour cherry is achieved by training of trees to form smaller canopies not by means of dwarfing rootstocks but by growth moderation techniques. The rootstocks traditionally used cause vigorous growth, and it is up to the technology to apply procedures less utilised earlier for that purpose. One of those techniques is the transfer of hibernal pruning to the estival period. The best term of the latter is the period of 1-3 weeks after fruit harvest.
The prolongation of the period of favourable illumination and the reduction of the canopy size facilitate higher densities of planting (number of trees per hectare) and a better exploitation of the crown (specific yield). The regular use of summer pruning resulted also in a better quality of fruit.
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Giant reed (Arundo donax L.) from ornamental plant to dedicated bioenergy species: review of economic prospects of biomass production and utilization
39-46.Views:530Giant reed (Arundo donax L.) is a perennial, herbaceous grass, it has been spread all over the world from continent to tropical conditions by human activities. In continental climate, especially Hungary, it has been considered as ornamental species, due to its decorative appearance, striped variants’ colour of leaves, long growing season and low maintenance requirements. It does not produced viable seeds, so it can be propagated vegetative ways by rhizomes or stem cuttings and by in vitro biotechnology methods. Because of its growth habits and good adaptation capability, it has been considered invasive weed primarily in coastal regions in warmer climate areas. In the previous century, giant reed produced for paper/cellulose/viscose production, woodwind musical instruments, stakes for plants or fishing rods etc. Over the last few decades, it has been produced for bioenergy purposes (bioethanol, biogas, direct combustion) or utilize as chemical basic compounds or construction materials. It has been considered a dedicated promising biomass crops thanks to high biomass production, high energy balance of cultivation and adaptability of different kind of soils and conditions. The objective of the present paper is to overview the most significance literature data on giant reed production and utilization, compare to own experimental data and economic calculations and to determine some critical factors, advantages and disadvantages of giant reed production compare to other biomass species.
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Farm economic evaluation of raspberry production
53-56.Views:289Hungary was considered as one of the most significant raspberry producers in the 1980’ies. The acreage and the produced quantity, however, reflected a decreasing tendency during the past two decades: the 7 000 hectares existing in the year of 1990 reduced to 1 500 hectares, the current territory does not reach the 500 hectares. The annual yield is only 1 to 3 thousand tons. The level of domestic fresh consumption is very low, due to the fact that it is a relatively expensive fruit for Hungarian consumers. The requirement of the processing industry is satisfied by raspberries from mainly Polish and Serbian import. These two countries belong to the biggest raspberry producing countries in the world by producing raspberries of more than 50 thousand tons. Comparing to the Hungarian production costs and yields they are able to transport their products here at a very low price, consequently they hold the prices at a low level. The profitability of the domestic raspberry production is rather unfavourable, production often shows a deficit even in orchards of good standard; furthermore the lack of labour causes an extremely great difficulty, which is an important component of the decline of the production independently from cost conditions.
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New evaluation method to detect physiological stress in fruit trees by airborne hyperspectral image spectroscopy
37-40.Views:204Nowadays airborne remote sensing data are increasingly used in precision agriculture. The fast space-time dependent localization of stresses in orchards, which allows for a more efficient application of horticultural technologies, could lead to improved sustainable precise management. The disadvantage of the near field multi and hyper spectroscopy is the spot sample taking, which can apply independently only for experimental survey in plantations. The traditional satellite images is optionally suitable for precision investigation because of the low spectral and ground resolution on field condition. The presented airborne hyperspectral image spectroscopy reduces above mentioned disadvantages and at the same time provides newer analyzing possibility to the user. In this paper we demonstrate the conditions of data base collection and some informative examination possibility. The estimating of the board band vegetation indices calculated from reflectance is well known in practice of the biomass stress examinations. In this method the N-dimension spectral data cube enables to calculate numerous special narrow band indexes and to evaluate maps. This paper aims at investigating the applied hyperspectral analysis for fruit tree stress detection. In our study, hyperspectral data were collected by an AISADUAL hyperspectral image spectroscopy system, with high (0,5-1,5 m) ground resolution. The research focused on determining of leaves condition in different fruit plantations in the peach orchard near Siófok. Moreover the spectral reflectance analyses could provide more information about plant condition due to changes in the absorption of incident light in the visible and near infrared range of the spectrum.
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Apple powdery mildew caused by Podosphaera leucotricha: some important features of biology and epidemiology
45-51.Views:435In this review, some important features of biology and epidemiology are summarised for apple powdery mildew (Podosphaera leucotricha). In the first part of the review, the geographical distribution or the pathogen are discussed, then the morphology and taxonomy of the causal organism are described. Disease symptoms or apple powdery mildew are also shown and then host susceptibility/resistance is discussed in relation to durability of resistance. In the second part of this review, the general disease cycle of powdery mildew on apple are demonstrated and some basic features of powdery mildew epidemiology (such response of the pathogen to temperature, relative humidity, and rain as well as spore production, spore dispersal, diurnal patterns and temporal dynamics of the pathogen/disease) are also given on apple host.
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Floral bud development, blooming time and fertility relations of some Romanian apricot varieties in Hungary
41-43.Views:302Due to the geographical situation of Hungary the introduction of late ripening apricot varieties holds great interest. In apricot production floral bud development during winter, blooming time, and the fertilisation properties are important factors. These characters were studied in six late ripening Romanian apricot varieties (Callatis, Comandor, Litoral, Selena, Sirena, Sulmona) in Szigetcsép representing the northern site of the lowland growing area. During the mild winter of 1997/98 the dynamics of floral bud development in the Romanian varieties was a few days slower during the whole examination period compared to Gönci magyar kajszi. Their meiotic divisions occurred between 1 and 5 February. Next winter the meiotic division started later at 28 February, due to the cold weather. In these conditions the dynamics of bud development was similar in all the varieties. Averaged over seven years blooming of the Romanian varieties started 1-3 days later than in Gönci magyar kajszi. All the Romanian varieties showed self-fertility to some extent, however, application of other pollen donor sources is necessary for the safety of production, with the exception of Callatis.
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Economic aspects of applying hail protection nets in apple plantations
99-101.Views:240The up to date intense apple growing in Hungary is capable to produce yearly about 500-1000 thousand Ft/ha income, which means that the investment of 4 000–5 000 thousand Ft is returned by producing 10-20% net income. The economic balance may, however, be upset by the damage caused by hail, quantitative and qualitative, with an apparently increasing frequency experienced in each third or fourth year. Estimates prove that each hail causing 50% damage may reduces the income proportionately to the capital by 1.5–2.0 percent points, which means a serious threat for the economy of apple production. According to calculations, a plantation producing 30–40 t/ha yields would not be able to raise incomes compensating the investment of 7.0–10.0 million Ft/ha, let alone the frequencies of hail damages. Consequently, 50–60 t/ha yields are needed to become successful, and in planning of new plantations those high yields are aimed with hail nets. An additional difficulty is represented by a lack of financial resources to install hail protection nets.
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Comparative study of cherry varieties used in intense culture
71-74.Views:191Research in sweet cherry production is intensely stimulated worldwide. The programs started also in Hungary to develop technologies and to find suitable varieties for the purpose of intense cultivation. It means that dimension of crowns should be smaller, with higher number of plants per hectare. Understocks, which let grow the trees slower, are scarce in this species. On the one hand, the braking effect of the respective stocks is insufficient, they get old pretty soon, loose ramification, yield too small fruits and do not comply with the aims of intense cultivation. Experiences prove the necessity of stocks for intense culture, which are vital, growing, easily regenerating, and freely branching. Mahaleb (Prunus mahaleb), a strong growing stock, is still suitable. Further improvement is expected from the contribution of technological elements and the choice of variety. In the present paper, a 9-year old plantation is shown with trees trained to (slender) spindle, and the yield and fruit quality of the year 2009 has been analysed with 6 varieties involved.
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Resistance gene Sw-5 of tomato confers resistance to TCSV in Solanum melongena
41-47.Views:152Eggplants transformed with Sw-5 gene, regenerated by organogenesis and somatic embryogenesis, were resistant to the Tomato chlorotic spot virus, while wild plants did present systemic infection. TO plants were selfed and the segregation analysis of T1 and T2 generation indicated the existence of one or more insertion sites. Southern blot analysis confirmed one or two independent insertions in T2 plants. Different lesions associated with the insertion number were observed in TI and T2 plants. T2 plants with two copies displayed faster hypersensitive reactions and characteristic necrotic lesions that contrasted with slower responses and necrotic ring lesions in plants with one copy. These results suggest that the Sw-5 confers resistance to tospovirus in transgenic eggplants and that the resistant phenotype depends on the number of transgene copies.
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Some biological properties of new sweet cherry cultivars in Bulgaria and their susceptibility to Blumeriella jaapii
95-97.Views:344Investigations were made on 12 sweet cherry cultivars (‘13-S-22-8’, 'Sunburst', `Kozerska'., 'NY 13791', 'Royalton', 'NY 13688', 'Hartland', `Sumerset', 'Pollax', 'Patriotka Krima', 'Castor', and `Lapins') in an experimental orchard of cherry cultivar collection in the Institute of Agriculture at Kyustendil, Bulgaria during the period of 1997-2003. The trees were planted in 1996. All cultivars were grafted on Prunus mahaleb. Four biological properties of the cultivars were assessed such as blooming time, resistance to late spring frost, fruit ripening and fruit mass. Among cultivars, a good resistance to late spring frost was observed on cultivar 'Sunburst'. The fruit mass varied between 4.2 g (cv. 'Patriotka Krima') and 8.5 g (cv. `Sunburst'). The susceptibility of the cherry cultivars to cherry leaf spot caused by Blumeriella jaapii was assessed in mid-September in each year. The estimation of the rate of attack was made according to the grade of Townsend and Neuberger. All cultivars showed symptoms of cherry leaf spot but the degree of susceptibility was different. Cultivar `Patriotka Krima' was the least susceptible, while cultivar `Somerset' was the most susceptible to Blumeriella jaapii.