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• Researches concerning the selection of some nectarine varieties as genitors for the breeding program in Romania

  44-46.

  A. Ivascu

  Views:

  181

  Researches concerning the selection of some nectarine varieties as genitors for the breeding program in Romania

• Economic figures of sour cherry production at national level of Hungary

  107-109.

  J. Felföldi

  Views:

  372

  After the political changes of 1989, economical processes impaired heavily the Hungarian fruit growing branch, more particularly production of sour cherry. Paralleling with the increasing mass of production, producer’s prices dwindled drastically. At present, Hungarian growers cannot cover the costs of production, nay, hardly raise income. My purpose was to analyse the cost and income relations of the sour cherry branch during the period of 2002-2009 years in order to find out what are the decisive features, which reveal the trends to be considered. The data presented in the paper are means of a heterogeneous population of values, which cannot be utilised for immediate use in management, but they may reveal the challenges and tendencies of economics of the branch.

• The effect of cooling irrigation on the blooming dynamic of plum

  57-59.

  L. Lakatos

  I. Gonda

  M. Soltész

  Z. Szabó

  J. Nyéki

  Views:

  902

  The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.

• Selection of the chance seedlings of `Mézes körte' (Pyrus communis L.) from the gene bank of Keszthely

  21-27.

  J. Varga

  J. Iváncsics

  G. Kocsisné Molnár

  J. Nyéki

  Views:

  712

  We 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.

• Prediction infection risk on the basis of weather-related factors and Erwinia amylovora colonization in apple and pear flowers

  39-54.

  T. Bubán

  E. Rutkai

  L. Dorgai

  S. V. Thomson

  Views:

  305

  Current infection risk prediction models utilize environmental parameters and field records, but do not take into account the estimated inoculum potential within the orchard. The object of this study was to survey the accuracy of three simple prediction methods under Hungarian climatic conditions, which could easily be used by the farmers. We also tested whether the accuracy of infection risk predictions can be improved by taking into consideration the incidence and/or rate of flower colonization by Erwinia amylovora.

  After preliminary investigations in 1999-2001, data concerning the weather-related infection risk were recorded in 5 apple and 1 pear orchards in 2002, and in 12 apple and I pear orchards in 2003. The weather data were processed by the easy-to-use risk assessment models of the mean temperature prediction line (MTL), Smith's Cougarblight 98C and Billing's integrated system (BIS), and by the Maryblyt^TM 4.3 computer-assisted model for reference. The population size of E. amylovora in the flower samples was estimated within an order of magnitude by PCR.

  For all years and orchards tested, Maryblyt indicated 35 days on which there was an acute infection risk. The same days were indicated by all 3 methods in 23 cases (66%), 8 days were indicated by 2 methods (23%) and 4 days were indicated by 1 method only. A similarly good correlation was found for prediction of the date of the first massive infection risk: in 2003, for instance, there was a perfectly consistent prediction by all 4 models in 9 of the 13 participating orchards. A coincidental forecast was provided by 3 of the 4 models in the other 4 orchards.

  The results indicate that any of the risk assessment models could provide an increased accuracy of the actual infection risk prediction if combined with an estimation of the incidence of Erwinia amylovora colonization in the open flowers. We found no convincing differences in the size of the epiphytic population in flowers of cultivars possessing high or low susceptibility to Erwinia amylovora.

  We conclude that the easy-to-use methods tested could be used by the fanners to recognize weather-related risks, especially when coupled with an estimation of the proportion of the pathogen-infested flowers. This local prediction would provide rapid information (faster than the regional forecast systems) specifically for a given orchard.

• 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.

  K. Magyar-Tábori

  J. Dobránszky

  É. Jámbor-Benczúr

  T. Bubán

  J. Lazányi

  J. Szalai

  A. Ferenczy

  Views:

  544

  Rooting 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.

   

• Legal harmonization of the Hungarian horticulture conditioned by the accession

  23-28.

  S. Farkas

  Views:

  312

  In 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.

   

• Effect of reduced spray programmes on incidences of apple scab, powdery mildew and codling moth damage in environmentally freindly apple production systems

  75-78.

  I. J. Holb

  M. Fazekas

  F. Abonyi

  P. Lakatos

  S. Thurzó

  J. Nyéki

  Z. Szabó

  J. Kruppa

  B. Balla

  Views:

  1489

  Still a large amount of pesticides and spary applications are used in environmentally friendly fruit production systems; therefore, the aim of our study was first to test the in vitro effeicacy of some fungicides against a key apple disease (apple scab), and secondly to evaulate the effectiveness of reduced spray programmes against apple scab, powdery mildew and coding moth in integrated and organic apple orchards. In vitro efficacy of 7 fungicides (Champion 50 WP, Kocide 2000, Nordox 75 WG, Olajos rézkén, Kumulus S, Rézkén, Rézoxiklorid) and another 6 fungicides (Score 25 EC, Efuzin 500 SC, Systane, Folicur Solo, Zato Plusz, Rovral) approved in organic and integrated production systems, respectively, were tested against apple scab. Altogether four spray programmes were performed i) standard integrated: sprays followed by forecasting systems during the season, ii) reduced integrated: sprays followed by forecasting systems but only 75% of the spray numbers used during the season-long spray programme, iii) standard oragnic: sprays applied every 7–14 days during the season and iv) reduced organic: 60% of the spray numbers used during the season-long spray programme. In vitro results showed that fungicides (with active ingredients of copper and sulphur) applied in organic production showed relatively high percent growth capacity of the apple scab fungus. Rézkén showed the highest and Kumilus S the lowest efficacy against apple scab. Fungicides applied in integrated production showed relatively low percent growth capacity of the apple scab fungus. Score 25 EC showed the highest and Rovral the lowest efficacy against apple scab. Field study showed that reduced spray programmes did not increase significantly scab incidence in the integrated field. However, scab incidence increased significanly (above 30%) in the reduced spray programme for the organic orchard.Mildew incidence was low (below 5%) in both integrated and organic spray programmes. Mildew incidence on both shoots and fruits increased significanly in the reduced spray programme for the organic orchard. Incidence of codling moth damage was affected the most by standard vs. reduced spray programmes. Though incidence remained below 10% in the integrated plots, the incidence was significantly higher in the reduced spray programme compared to the standard programme. Similar results were obtained for organic spary programmes, but the incidence was 10 times higher and the differences among the two programmes were larger.,

• Examination of valuable ingredients of some wild fruits

  71-74.

  B. Z. Sipos

  N. Szabó

  M. Stéger-Máté

  G. Schmidt

  Views:

  369

  A 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.

• Sex expression of flowers in cultivated sweet and sour cherries

  50-52.

  D. Surányi

  Views:

  353

  During 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.

• Preliminary characterization of the self-incompatibility genotypes of European plum (Prunus domestica L.) cultivars

  23-26.

  J. Halász

  A. Kurilla

  A. Hegedűs

  Views:

  519

  European plum is an important fruit crop with complex, hexaploid genome of unknown origin. The characterization of the selfincompatibility (S) locus of 16 European plum cultivars was carried out using the PaConsI-F primer in combination with the EM-PC1consRD primer for the first intron and the EM-PC2consFD and EM-PC3consRD primers for the second intron amplification. Altogether, 18 different alleles were scored indicating high genetic diversity. These alleles were labelled using alphabetical codes from SA to SS. We  identified 5 different alleles in 9 cultivars, 4 alleles in 5 cultivars, while 3 alleles were shown in two of the assayed cultivars. A total of 16 different S-genotypes were assigned, and discrimination of all plum cultivars was successful based on their unique S-genotypes. However, further research is required to reliably identify the S-alleles based on their DNA sequence and clarify complete S-genotypes.

• Influence of environment in electro-chemical quality of tomato

  17-20.

  S. Kaciu

  V. Shala-Mayrhofer

  N. Mirecki

  S. Aliu

  K. Jezik

  Views:

  308

  The aim of the research was to investigate the impact of different cultivation environments of tomato cultivars, the electro-chemical and the qualitative traits of the tomato fruits. The quality of tomato fruit harvesting was evaluated at the Laboratory of Institute of Horticulture and Viticulture University of Natural Resources and Applied Life Sciences, Vienna. Two hybrids of tomatoes were tested Belle-F1 and AmaF1, in two locations and two different treatments (open field and plastic tunnels). Model of experimental fields was based on random method and included three replications. Following parameters were analyzed and tested: pH, Rh, P-Value, Nitrates and the content of vitamin C. The values of pH for treatment in the open field and indoor production system were not significant (4.47 to 5.05). For P-Value derived from the two treatments the maximal values were without significant differences, while minimal values were significant. Study has shown also that the highest values of nitrate content (16.34 mg, open field) compared to average value differences were + 0.384 mg or 43.83% higher. In indoor production the nitrate content was lower in compared with plants cultivated in open fields, so these differences were +3.81 mg or 26.4 0%, and highly significant for both levels. In relation to vitamin C content, the highest value was identified in the indoor systemof 298.6mg, with variations from the overall average of 16.43% or + 42.15 mg. The coefficient of variation values for both levels was of 29.96 respectively 27.31%.

• Nutritional values of traditional open-pollinated melon (Cucumis melo L.) and watermelon (Citrullus lanatus [Thumb]) varieties

  29-31.

  Cs. Szamosi

  H. Némethy-Uzoni

  G. Balázs

  É. Stefanovits-Bányai

  Views:

  537

  The aim of our experiments was to investigate the internal quality parameters of some old melon and watermelon landraces or varieties whether they have any desirable characteristics. Measurements were carried out using 8 different types of melon (Cucumis melo L.) and 8 accessions of watermelon (Citrullus lanatus [Thumb]), which were self pollinated under greenhouse conditions. Besides the determination of dry matter content; soluble solids, titratable acidity of the fruit juices, investigation of carbohydrates, total phenol content was measured by spectrophotometer. Total antioxidant capacities were determined spectrophotometrically using the FRAP method. We found some accesions both among melon and watermelon varieties, which could be characterized by outstanding inner content.

• Total anthocyanine content and antioxidant density of some Hungarian sour cherry varieties

  109-111.

  Zs. Veres

  I. J. Holb

  J. Nyéki

  Z. Szabó

  M. G. Fári

  Views:

  1341

  Evidence suggests that a diet high in fruits and vegetables may decrease the risk of chronic diseases, such as cardiovascular disease and cancer, and phytochemicals including phenolics, flavonoids and carotenoids from fruits and vegetables may play a key role in reducing chronic disease risk. Recent research has proven that sour cherry (Prunus cerasus L.) is a valuable natural source of some bioactive compounds important in human health preservation. In our work, we identified the total antioxidant activity, anthocyanine content and "antioxidant density" of sour cherry varieties named "Újfehértói fürtös", "Debreceni bőtermő", "Kántorjánosi" and "Érdi bőtermő" and those of the "Bosnyák" sour cherry clones. "Antioxidant density" is a biological value indicator obtained in a synthetic way, which indicates the antioxidant capacity of the particular food, e. g. fruit and vegetable, related to 1 Calorie.

• Influence of irrigation and row spacing on the growth, seed yield and active substance of milk thistle (Silybum marianum)

  78-81.

  G. Karimzedah

  R. Omidbaigi

  Bakhshai D.

  Views:

  287

  Milk 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.

   

• Nectar production of pear (Pyrus communis L.) cultivars

  67-75.

  P. Benedek

  G. Kocsisné Molnár

  J. Nyéki

  Views:

  978

  Detailed 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.

   

• Anatomical study of the bud union in „Chip" and „T" budded 'Jonagold' apple trees on MM 106 rootstock

  27-29.

  Gy. Végvári

  K. Hrotkó

  Views:

  695

  The traditional methods for vegetative propagation of apple and its varieties are the T-budding, and the winter grafting, but this latter way is a difficult and expensive procedure.

  In our experiment carried out in the Fruit Tree Nursery Soroksár, the healing process of chip- and T-budded apple trees 'Jonagold' on MM 106 rootstock was studied.

  The budding (T- and Chip-) was made in the first week of August, samples for microscope examination were taken monthly after this time until leaf fall.

  The investigated part of plants was made soft with 48 % HF (hydrogenfluoride), then cross and longitudinal section were made and examined by microscope.

  Based on analysis of microscope pictures in case of Chip-budding, it was established, that development had started quickly after budding on the rootstock and scion too. But the callus originated almost entirely from the rootstock tissue as new parenchyma cells fills the gap between the two components of graft (scion and stock), becoming interlocked and allowing for some passage of water and nutrients between the stock and the scion. This quantity of callus in case of T budding was under the scion buds larger, than the Chip-budded unions, where the thickness of callus mass is uniformly thick round the chip. The large mass of callus pushes the scion bud outwards from the shoot axis, which later results in a larger shoot-curvature above the bud union.

  Following this process on the Chip-budding it can be observed also, that a continuity of the cambium is established between bud and rootstock. Then the newly formed cambium started typical cambial activity, forming new xylem and phloem.

  Later the callus begins to lignify, and it is completed within about 3 months after budding.

   

• Hungarian apple growing and marketing on the doorstep of the European Union

  15-18.

  E. Kállay

  T. Kállay

  Views:

  233

  The scope of apple growing and marketing has been determined by the economic and political systems in the recent decades. One may follow the booms and collapses in the Hungarian apple industry. Re-establishment of the market economy gives new chances for recovery in the fruit section as well.

  Reconstruction of the apple industry has started with private ownership of lands. In the present work we characterise the still existing apple farms inherited from the previous system, present the newly established orchards in detail, deal with the present state of apple commerce and finally, we try to predict the near future of Hungarian apple industry.

• Farm economic evaluation of elderberry production

  57-60.

  F. Apáti

  Views:

  502

  In 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.

• Conditions of rentability in the apricot industry of Hungary

  127-129.

  F. Apáti

  Views:

  457

  Total 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.

• The inheritance and durability of scab resistance in apple progenies

  39-46.

  M. Tóth

  A. Pedryc

  Views:

  365

  In order to select the appropriate parent cultivars and maintain the durability of resistance, it is important to clarify the mechanisms of inheritance of scab resistance depending on the parents. It has been known that the progeny segregation ratios based on scab-resistance do not depend only on the genotype of the resistance locus but also on the genetical makeup of the donor and recipient parents as well as on the susceptible parent.

  The aim of this study has been to demonstrate what factors in the Vf, Vr and VA scab-resistant cultivars — combined with susceptible and resistant parents — affect the inheritance and durability of resistance in seedlings in their first 4 year's growing four years' growth. After inoculating apple seedlings sown in 2001 with the suspension of Venturia inaequalis (Cke.) Wint. in the greenhouse, we studied the segregation ratios of the progenies into reaction classes. Seedlings showing resistance in the greenhouse were also evaluated for scab-resistance after they had been moved to the field and had naturally been infected with the pathogen in 2002 and 2004.

  The majority of our results obtained in the greenhouse test, similarly to earlier experiences, have not justified monogenic inheritance at the phenotypic level. The effect of susceptible parent cultivars on the segregation ratio of progenies have become apparent again. The high infection rate of seedlings in the field trials, which had previously exhibited varying degrees of resistance in the greenhouse test, has raised concern. Our data has raised further doubts, concerning the durability of Vf resistance in Hungary. It is assumed that the composition of natural field populations of Venturia inaequalis in Szigetcsép has changed. The complexity of Vf resistance has been confirmed. The high infection rate in the progenies derived from Vf resistant cultivars draws the attention to the importance of utilizing additional sources of resistance.

• Investigation on the transmission of some Tobamoviruses by pollen and seed in pepper (Capsicum annuum L.)

  127-131.

  P. Salamon

  M. Kaszta

  Views:

  371

  Five pepper cultivars were mechanically inoculated with isolates of three Tobamovirus species, viz. the "Gelb" strain of tobacco mosaic virus (TMV-G), the XM-isolate of dulcamara yellow fleck virus (DYFV-XM) and the Nov/H isolate of pepper mild mottle virus (PMMV-Nov/H), respectively. Symptoms caused by the viruses were characterised. The viruses were sucessfully re-isolated from different organs (roots, leaves, fruit parts) of susceptible peppers to test plants. It was estabilished, that the pollen of diseased peppers carried infective virions at least on their surface. Washes of seeds were highly infective, but no infectivity was found after treatment of the seeds with 2% NaOH or 10% Na3PO4. No infectivity of inocula prepared from seed-coats of alkaline treated seeds was established. Infection of young seedlings grown from untreated seeds was demonstrated, while the seedlings came from alkaline treated seeds remained free of infective virus. The possible role of pollen and seed in the epidemiology of Tobamoviruses pathogenic to pepper as well as the importance of seed treatment is discussed.

• Knot formation by Pseudomonas syringae subsp. savastanoi on the in vitro shoots of Sorbus redliana

  59-62.

  M. Hevesi

  J. Papp

  E. Jámbor-Benczúr

  Gy. Gazdag

  Views:

  511

  Two strains of Pseudomonas syringae subsp. savastanoi were isolated from Forsythia sp. and Nerium oleander in Hungary in 1997. The effects of growth regulators produced by the bacteria were studied in different experiments. The strains were co-cultured with Sorbus redliana in vitro shoots without being in contact with the plant on solid media. Further culture filtrates in different concentrations were added to the culture medium. The growth regulators presented in the agar caused knot formation on the shoots and on the leaves in both kinds of culture. There were significant differences in the cultural and physiological characters, auxin and cytokinin activity of the strains of different origin.

   

• Burrowing nematode (Radopholus similis) abundance, distribution and agronomic impact on bananas in Kirinyaga County, Kenya

  7-14.

  P. Gatheru

  W. M. Thagana

  Nchore S. B.

  Views:

  82

  Burrowing nematodes (Radopholus spp.) are the most significant parasites of bananas (Musa spp.) world over. They feed on the root tissue of bananas resulting to toppling disease at the fruit bearing stage. This study assessed the impact of farmers selected agronomic practices that influenced distribution of burrowing nematodes. We also assessed the abundance of Radopholus spp. across four AEZs namely; UM 2, UM 3, LM 3 and LM 4 of Kirinyaga County, Kenya. Purposive sampling was done on April, 2024 targeting farmers that grew ‘dwarf Cavendish’ variety of bananas, those that grew an average of 25 banana stems and those whose farms that were 1km apart. A structured questionnaire was issued to ninety farmers to collect demographic information and to determine their awareness of burrowing nematodes and toppling disease. Soil and banana root samples were also collected to determine abundance and distribution of burrowing nematodes. Data from the questionnaire and samples was subjected to R -statistical software and analysed at p≤ 0.02. The study revealed that majority of banana farmers practised mixed cropping and were not aware of toppling disease associated with Radopholus spp. It also revealed that majority of banana farmers were male and of ˃ 50 years of age. The findings also showed Radopholus spp was rarely distributed in lower AEZs of LM 3 and LM 4 compared to Pratylenchus spp. which was pre- dominantly distributed in upper AEZs of UM 2 and UM 3 in both soil and root samples.

• Effects of DMI and strobilurin fungicide combinations on scab and powdery mildew incidence in apple production: a preliminary study

  37-39.

  I. J. Holb

  M. Kocsis

  J. Kruppa

  F. Abonyi

  Views:

  724

  The aim of our study was to evaulate the effectiveness of four DMI and strobilurion fungicide combinations in a season-long disease management programme against apple scab and powdery mildew in two integrated apple orchards on cultivar Jonagold. The four spray programmes were: i) standard, ii) DMI dominant iii) strobilurin dominant, and iv) DMI and strobilurin dominant. Apple scab incidence as generally high in both orchards in the standard fungicide treatment plots ranged between 21.8 and 26.4%. Leaf scab incidence was higher in all treatments compared to fruit incidence. Scab incidence was generally higher at Mándok compared to Ófehértó. In both locations the lowest scab incidence was assessed in DMI dominant treatment ranged between 5 to 10.7%, which was not signifi cantly different from the DMI and strobilurin dominant treatment. Powdery mildew incidence was generally low in both orchards in all fungicide treatments ranged between 0.002 and 0.5%. Although there were no signifi cant differences among treatments, the lowest powdery mildew incidence was assessed in the DMI and strobilurin dominant treatment in Mándok and in the strobilurin dominant treatment in Ófehértó.