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• Estimating of water consumption of cherry trees

  15-17.

  Á. Juhász

  L. Tőkei

  Z. Nagy

  K. Hrotkó

  Views:

  398

  Despite of its importance there is no exact information on water use of new scion/rootstock composite trees, which would be needed to optimized irrigation. Our research purpose is to define exact water-demand of different rootstock/scion composite trees, calculating seasonal weather changes and by using the results decrease irrigation costs. The investigations are carried out in Soroksár, at the Experimental Farm of Corvinus University of Budapest in May 2008. From among the investigated trees two are budded onto Prunus mahuleb `Érdi V' seedlings, two on "Korponay' seedlings. The sapflow measurements are carried out using Dynamax Flow 32 equipment with Dynagage trunk sensors. The first daily maximum of sapflow was around 10:00 a.m. (2.5 kghour I), the second maximum was always between 14:00-15:00 p.m. (2 kgday<sup>-</sup> I). Comparing to the very intensive morning water uptake by 20:00 p.m. the water flow slowly reached the minimal level. Significant differences can be seen on rootstocks: trees on `Korponay' rootstock always showed more intensive sapflow and a higher morning peak than trees on `Árdi V'. But later during the day they have the same run.Based on our results the water quantity transpired only by the trees reached in May 86-104 mm, while the precipitation was only 42.4 mm. This means a 40-60 mm deficit in the orchard, which should have been supplied by irrigation despite of the satisfying horticultural performance of the orchard. In the first half of the month beside the steady vapor pressure deficit the shoot and leaf surface growth could cause the increased sapflow.

• The effect of potassium fertilization on the inner values of spice pepper

  27-29.

  B. Irinyi

  J. Kapitány

  I. Terbe

  Views:

  329

  To reserve the fertility of soil is the basic condition of successful cultivation. The field specific nutrient supply, based on soil tests is very important in both economy and ecology aspects. Spice pepper plants have high nutrient demands. Proper nutrient supply has importance not only from the point of potential yield levels, but make a major contribution to quality. This is the reason which necessitates the rational development of nutrient supply as an the elements of the production technology. Our objective was to offer a contribution to this job through our nutrient trials. Experiments on the nutrient supply of spice pepper were set up in the 2005 growing season in order to decide whether yields and fruit composition parameters of pepper could be increased by means of increased K fertiliser closes with lower N:K ratios. Several forms of potassium were used, as well as applying microelement top dressings in the single treatments. It was found that higher K doses lead to increased yields, and the influence on dry matter and pigment content proved beneficial too. Potassium applied in the form of patentkali seemed to be better than in that of potassium-sulphate.

• 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.

• Microsporogenesis of peach (Prunus persica L. Batsch) varieties

  7-10.

  L. Szalay

  B. Timon

  Z. Szabó

  J. Papp

  Views:

  1068

  Bud 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.

• The estimation of pollen viability of snowdrop (Galanthus nivalis L.)

  141-144.

  G. Kovács

  Views:

  238

  In the present experiment pollen viability of snowdrop were tested using four vital dyes (TTC, Baker' procedure, MTT and FDA) to determine their potential to differentiate fresh living pollen from pollen heated for 12 hours at 80 °C (killed pollen). We found that two of the four dyes previously employed to determine viability also stained killed pollen in the case of snowdrop, while the FDA and MIT did not. We suggest that the two latter are probably the best method to test snowdrop pollen viability, since they do not normally stain either killed or aborted pollen.

   

• Nutritional quality, fruit shape and relationships among exotic and local Capsicum pepper genotypes in Uganda

  33-39.

  S. Asiimwe

  M. Ochwo-Ssemakula

  P. Ssekkadde

  C. Ribeiro

  J. Karungi-Tumutegyereize

  Views:

  529

  Twenty-one hot pepper genotypes comprising of local (15) and exotic (6) types (C. annuum, C. frutescens and C. chinense) were characterized for selected fruit traits after propagation in a glasshouse at the Makerere University Agricultural Research Institute Kabanyolo in Central Uganda using a completely randomized design with three replicates. Ripe fruits were harvested and analyzed; traits evaluated were all significantly different at P<0.05 with variations in quality attributes. The genotype OHA-B305-10 had the highest ascorbic acid content (128.86 mg/100 g) and is recommended for improvement of both local and exotic genotypes targeting the fresh market. Genotypes CAP0408-12 and UG2 WE0511-22, with highest total soluble solids (16.17 ºBrix) and dry matter content (28.59%), respectively should be used in improvements for industrial use or processing to products such as chilli powder or flakes. BRS-M205-04 with highest titratable acidity (1.04%) can be used in enhancing shelf life of genotypes with low titratable acids as well as for the fresh market. In spite of the intraspecific relationships among genotypes, significant differences were observed in their quantitative traits. These genotypes will, therefore, be useful in improving the quality of hot pepper fruit in Uganda.
  
  

• Virus and virus-like diseases of grapevine in Hungary

  25-36.

  J. Lázár

  Gy. D. Bisztray

  Views:

  460

  Viruses and viroids are submicroscopic infectious particles which can cause disease symptoms on grapevine. These parasites are depending completely on the energy metabolism of the plant cell. To enter the host cell plant viruses depend on injuries or on transmission via invertebrates (insects, nematodes, etc.). Viruses are classified by many characters including particle morphology, host range and information content of the genome. At present about 70 viruses including 7 viroids infecting grapevine are known. In single or mixed infections they are potentially detrimental to the quality and quantity of grape production in any growing area of the world. Some viruses can cause severe economic damage in vineyards. In Hungary many important viruses and viroids have been detected in grape. This review summarises characteristics of viruses and the results of detection and characterization of virus and virus like diseases of grapevine in Hungary. The identification of the causal agent, its transmission, geographical distribution and the development of the diagnostic methods are also discussed.

• Bioactive phenols in leaves of Forsythia species

  57-59.

  É. Sedlák

  L. Borsodi

  E. Boldizsár

  É. Preininger

  M. László

  É. Szőke

  I. Gyurján

  Views:

  403

  Nowadays a number of lignans (arctigenin, matairesinol, pinoresinol and phillygenin) have come to the fore in research due to their various biological activities. In this paper the accumulation of these constituents in leaf extracts of Forsythia plants (F. intermedia, F. ovata 'Robusta’ and `Tetragold', F. suspensa, F. viridissima) was quantified using a new isolation method, supercritical CO<sub>2</sub> fluid extraction. The total phenolic and flavonoid contents, the antioxidant capacity and the aglycone lignan profile were determined in leaf extracts of Forsythia species. Within the phenols, the flavonoids were only present in small quantities, but the amount of aglycone lignans was extremely high. F. ovata `Robusta' had the highest total lignan content (103.8 mg/g) of all the Forsythia species. The main lignan in this species is arctigenin, which normally makes up about 60% of the total lignan content, but in the case of F. ovata `Robusta' this value was 96.1%. Since this arctigenin content is outstanding compared to that of other Forsythia species, it could be promising to develop a fermentation technology for the production of this natural compound.

• Allyl isothiocyanate baited traps to monitor cabbage flea beetles (Phyllotretra spp., Coleoptera: Chrysomelidae)

  95-99.

  P. Benedek

  F. Bakcsa

  M. Tóth

  E. Csonka

  Views:

  407

  A new trapping concept has been proposed based on a volatile compound, allyl isothyocianate, known to be attractant to some of these insects for a long time.

  (l) The first question was whether this compound is effectively attractive to all flea beetle species attacking cabbage under our conditions? Field experiments were made at different localities with non-sticky baited traps early and late spring. Eleven Phyllotreta species attacking cabbages were captured at baited traps most of them were first observed at this bait. So the bait has proved to be sufficient for use for trapping purposes effectively.

  • Based on these findings a second question arose whether the captured samples reflected the specific composition of natural flea beetle populations at trapping localities? To reply the question field samples were taken at four different kinds of cabbage crops and at a fallow ground in the close vicinity by a manual sampler device suitable to detect the local composition of flea beetles and trapping was made parallel with baited and unbaited traps from early spring to early autumn. No significant differences were found between the specific structures of Phyllotreta assemblages sampled with the different methods applied. This means baited traps reflected the specific composition of local Phyllotreta populations fairly well.
  • Thirdly, the most effective trap design was searched for. Some sticky and non-sticky trap designs which had been developed to capture other insects were compared. The tested sticky and funnel trap designs baited with allyl isothiocyanate captured large numbers of flea beetles attacking cabbages. Results showed that non-sticky funnel traps were more effective than sticky delta traps. Accordingly, non-sticky funnel trap designs can advantageously be used and could possibly be recommended in plant protection practice to monitor flea beetles attacking cabbages as their catching capacity is considerably greater than that of the delta type and additionally captured beetles are much cleaner, more intact and consequently their identification is much easier.

• The effect of rootstock on the nectar production of apple cultivar `Idared'

  15-25.

  E. Nagy Tóth

  Zs. Orosz-Kovács

  Views:

  236

  Approaches based on the daily rhythm of apple flowers provide a new stage in nectar research, where the synchronous functioning of sexual organs is studied. In the flower biological studies the insect attraction of flowers was also studied. The two most important factors of insect attraction are the pollen- and nectar production of the flowers. From 1993 to 1998 we studied the food, that flower had to offer for the pollinating insects at different times of the day.

  Studies were carried out on 'Idared', one of the hybrids of 'Jonathan' apple cultivar. The fruit of 'Idared' is bigger than the fruit of `Jonathan'. It is bright red, transportable, has a bigger productivity and is not subject to Jonathan-spots. Concerning its inner characteristics, it is juicy, the flesh consistency is better than that of 'Jonathan', but its acid/sugar ratio is worse (Sansavini et al. 1981).

   

• Floral attractivity of pear cultivar 'Cinderi'

  102-109.

  Á. Farkas

  J. Orosz-Kovács

  L. Gy. Szabó

  T. Bubán

  Views:

  407

  The 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.

• Agrobacterium transformation of Rhodiola sp.: current status and limitations

  37-42.

  A. Javid

  Zs. György

  Views:

  329

  The study of secondary metabolites has led to the discovery of new drugs for treating human diseases. However, consistent plant supply can be challenging, leading to the use of plant tissue culture techniques such as hairy root culture. Hairy roots have stable genetics, lateral branching, and can produce secondary metabolites, including alkaloids, flavonoids, and terpenoids. Research on hairy roots as a subject began in the late 19^th century, and for the last four decades, hairy roots have been utilized for producing secondary metabolites and recombinant proteins. This article focuses on Rhodiola species - genus of perennial plants that belongs to the family Crassulaceae - and its potential as a source of secondary metabolites using hairy root culture techniques. Rhodiola sp. is widely distributed throughout the Arctic regions of the Northern Hemisphere, with several species having significant medicinal properties. The article discusses the possible use of hairy root cultures for the production of Rhodiola secondary metabolites, including salidroside and rosavins, which have demonstrated significant pharmacological activity in various studies. The use of elicitation and genetic engineering techniques to boost secondary metabolite production in Rhodiola hairy roots is also explored. Overall, the article highlights the potential of Rhodiola hairy root cultures as a valuable source of secondary metabolites with medicinal properties. However, despite some studies Rhodiola hairy root induction and culturing still remains highly unexplored.

• Precision geoinformatical system of the pear gene-collection orchard

  43-50.

  J. Tamás

  A. Nagy

  T. Fórián

  J. Nyéki

  T. Szabó

  Z. Szabó

  Views:

  890

  The principle task of the sustainable development is the preservation of the genetic variety, which is similar challenge in the horticulture regarding the sublimation of fruit species. The breeders of the traditional fruit strains give stock to the sustenance diversity of the agro-environment on the species and landscape level. In 2009, hyperspectral images have been taken by AISA Dual sensors from the pear gene pool in Újfehértó, Hungary. The hyperspectral data cube (in the wavelength range of 400-2500 nm, with 1.5 m ground resolution) ensured possibility to make the spectral library of pear species. In the course of the simultaneously field work the spatial position and individual extent of all pear trees was defined to set up a detailed GIS data base. The water stress sensitivity of single species and the descriptive spectral curves were determined with common evaluation of the spectral and spatial data. Based on the unique methodology processing and the hyperspectral data base suitable strains can be chosen for agro-environment and let take adaptive stocks regarding climate change into the genetic grafting work. Furthermore we could determine and map the sparsely species in the region with the help of the hyperspectral data.

• Organic versus integrated apple growing: II. differences in fruit quality parameters

  61-63.

  P. T. Nagy

  Z. Szabó

  J. Nyéki

  I. Gonda

  I. J. Holb

  Views:

  891

  The aim our study was to establish whether significant differences in nutrients uptake and quality of fruit exist
  between organic and integrated grown apples. The study was performed at the orchard Fruit Research Station, University of Debrecen, at Debrecen-Pallag during 2002–2004. Diameter (mm), weight (g), firmness (N/cm2), dry matter (%) and Vitamin C in fruit were determined. Diameter data showed that the size of apples strongly depended on cultivars and organic apples were larger than integrated ones. Moreover, the effect of year and species strongly affected the apple diameter, size and weight. Measured data of firmness were good agreement in data of diameter and weight. Larger fruits have lower values of firmness due to the structure of fruit flesh. Dry matter content of apples varied between 14.66 and 18.07 in integrated, and 12.87 and 17.29 in organic apples according to cultivars. Values were affected by years and cultivars. From results it was evident that the dry matter content of apples affected by production system. It was lower in organic samples than integrated ones.Vitamin C content of apples was stronger affected by species and years than production system.

• Relationship between several meteorological factors and phenological features of apple cultivars

  13-19.

  L. Lakatos

  T. Szabó

  S. Zhongfu

  Y. Wang

  J. Racskó

  Z. Szabó

  M. Soltész

  J. Nyéki

  Views:

  1012

  The trees observed are grown at Ofeherto, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple cultivars. Each of the cultivars were observed as for their dates of subsequent phenophases, the beginning of bloom, main bloom and the end of bloom over a period between 1984 and 2001. during this period the meteorological data-base keeps the following variables: daily means of temperature (°C), daily maximum temperature (°C), daily minimum temperature (°C), daily precipitation sums (mm), daily sums of sunny hours, daily means of the differences between the day-time and night-time temperatures (°C), average differences between temperatures of successive daily means (°C). Between the 90^th and 147^th day of the year over the 18 years of observation. The early blooming cultivars start blooming at 10-21April. The cultivars of intermediate bloom start at the interval 20 April to 3 May, whereas the late blooming group start at 2-10 May. Among the meteorological variables of the former autumnal and hibernal periods, the hibernal maxima were the most active factor influencing the start of bloom in the subsequent spring.

• Review of the self-incompatibility in apple (Malus x domestica Borkh., syn.: Malus pumila Mill.)

  31-36.

  A. Hegedűs

  Views:

  882

  Apple (Malus x domestica Borkh.) is one of the most important fruit crops showing ribonuclease-mediated self-incompatibility, and no self-compatible apple cultivars are known. Twenty-nine S-alleles were identified in apple and many more incompatibility groups are present compared to sweet cherry. Results from a Belgian, English and a Japanese research group are combined and the S-genotypes of the most important world cultivars are collected. Two different allele labelling system are reconciled and detection methods used in case of the specific alleles are shown. Effects of the resistance breeding programmes are discussed; and scientific efforts involving transgenic technology to create self-compatible genotypes are shown. This review covers the most interesting issues regarding self-incompatibility in apple.

• Historical apple cultivars that display high level of resistance to fire blight

  19-23

  K. Kása

  M. G. Tóth

  M. Hevesi

  Views:

  294

  Following the first outbreak of fire blight caused by the bacterium Erwinia amylovora (Burrill) Winslow et al. in Hungary, we have started research with the aim to screen domestic gene sources, mostly historical Hungarian apple cultivars, for disease resistance as part of an apple breeding program for multiple resistance. The present study was conducted with the aim to choose the most tolerant historical apple cultivars among 25 selected cultivars by screening their behavior towards fire blight under controlled conditions. Six cultivars were shown to be the most disease tolerant: `Batul', 'London pepin', Nemes Sóvári Alma', `Sikulai', `Szemes alma', Wilmos renet'. We evaluated these cultivars by investigating both morphological- characteristics under original environmental circumstances and fruit quality. The cultivars had a remarkable degree of fire blight resistance compared to the control cultivars. These were not competitive with the commercially grown 'Jonathan M40' during cultivar tests but on the basis of certain characteristics they could serve as genetic sources for breeding new varieties.

• 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.

• The role of rejuvenated and adult forms of English oak (Quercus robur) in in vitro cultures

  81-83.

  Gy. Végvári

  I. Balla

  Z. Kothencz

  Views:

  312

  In vitro plant material of clones (Q. robur) NL 100 A (adult) and NL 100 R (rejuvenated) received from Germany (A. Meier-Dinkel, 1995) were used in these experiments. WPM medium was used for the multiplication phase. Plantlets were subcultured monthly. Differences in quality and colour of the adult and rejuvenated cultures induced us to follow and compare the changes of mineral- and chlorophyll content and dry weight during the propagation phase. Mineral and chlorophyll content as well as dry weight were measured weekly on three samples during the subculture period.

  In the case of propagation rates we stated, they were similar around the year, but both clones had a high peak in April. Examining the cation-content, we detected that, the plantlets had a highest quantity of several elements during the 2nd and 3rd week of subculture. The iron content was the highest in the 1st week and after that it decreased continuously. It is supposed, that the content of iron is not enough in the media. The chlorophyll content of the rejuvenated clone was higher than that of the adult one.

  In the rooting experiments it was stated that, after one-week cold treatment the rooting ability was the best.

   

• Effects of methyl jasmonate, salicylic acid and phenylalanine on aloe emodin and aloin in diploid and tetraploid Aloe barbadensis

  S. Shafighi

  A. Moieni

  S. Rashdi Monfared

  Views:

  438

  Aloe vera is one of the most famous medicinal plants. Aloin and aloe emodin are the most important active compounds in this plant. The purpose of this research was the comparison of aloin and aloe emodin production after the elicitation by methyl jasmonate, salicylic acid, and phenylalanine in diploid and tetraploid Aloe vera plants in greenhouse conditions. The plants were treated with the concentrations of 25, 50, and 100 µM. The amounts of aloin and aloe emodin were determined 24 and 48 hours after application of the treatment. HPLC analysis showed that the leaves of the control diploid plants (without applying elicitors) had more aloin (1.20 fold) and aloe emodin (1.14 fold) than the control tetraploid plants. The maximum concentration of aloin (1.15 ± 0.07 µg mg-1 dry weight) was obtained after the elicitation by 25 µM methyl jasmonate, 24 hours after treatment, in diploid plants) 6.36 fold compared to the control (0.18 µg mg-1 dry weight (. In addition, the maximum concentration of aloe emodin (0.28 µg mg-1 dry weight) was obtained after the elicitation by 25 µM salicylic acid, 24 hours after treatment, in diploid plants) 6.18 fold compared to the control (0.04 µg mg-1 dry weight)). The long-term effect of three studied elicitors (after 240 days) on plant health and survival was also studied. This investigation showed that only methyl jasmonate at a concentration of 100 µM was resulted in the death of Aloe vera plants.

• Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology

  19-23.

  I. Holb

  Views:

  576

  Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle.

• Colour stability of the flowers in some modern rose varieties in Hungary

  61-66.

  G. Boronkay

  E. Jámbor-Benczúr

  Á. Máthé

  Views:

  374

  A variety trial has been carried out to study the colour changing — colour stability of the flowers of some modern roses, especially of Hungarian varieties. 100 floribundas and polyanthas were observed. Colours of the petal surface were examined at three fenological stages of the flowers: at the bud, at the young open flowers and at the aged open flower stages. The colour difference was described in HLS standard. Our work shows that valuable Hungarian varieties can be found in both studied classes, but more floribundas bred in Hungary had good colour stability than polyanthas. The best Hungarian floribundas were 'Pest' and 'Remenyik Sándor emléke', although 'Regen', `Szent Lász1ó em­léke' and 'Szabó Dezső emléke' were quite good. The best Western-European floribunda rose was 'Perneille Poulsen'. Their colour stability was reliable in different situations. Colour changing of the two best varieties was almost unperceivable from the bud to the young petals and from the young to the aged petals. In the polyantha class there was only one perfect variety: the Czech `Cs1 Cerveny Kriz'. The 'Fairy Damsel' was almost excellent as well. The best Hungarian polyanthas were `Domokos Pál Péter emléke' and 'Savaria'.

• Dynamic economic analysis of greenhouse pepper production on rockwool on a family farm

  43-47.

  D. Tompos

  J. Bálint

  Views:

  238

  The major part of the pepper growing farms in Hungary operate as family enterprises with areas varying between 1,000 and 3,000 m². As a result of the small size, their profitability is greatly dependant on the technological level and market circumstances. Most of these farms are characteristically affected by the lack of capital, therefore, they are unable to implement any further developments with their own forces. Greenhouse pepper production on rockwool had already been subjected to analysis earlier in our research, however, those calculations were directed solely at the profitability and efficiency of production. Based on the data from 2004 in 2005 yet another and more profound analysis was set as the objective. Besides the methods already applied before, several dynamic indicators have been introduced which could also be useful for practical applications. The graphs can permit growers to monitor the temporal distribution of the costs incurred and revenues earned during production. Thereby it is easier to plan the costs and more simple to distribute them more rationally over the production period. Our experiences suggest that this sort of analytical method is applicable only in cases where a very careful and precise collection of data is ensured and the results obtained can not be generalised as being valid only for the single farm analysed. Experiences and results, however, make us consider the dynamic economic analysis as being very useful both for beginners and practicing horticulturists.

• Role of nutrient supply in yield increase and quality improvement of spice pepper

  83-86.

  B. Irinyi

  J. Kapitány

  Views:

  217

  Hungarian spice pepper powder is a unique product, a real hungaricum with its flavour and aroma compounds and seasoning effect. Its competitiveness with foreign spice peppers is ensured by its high biological value deriving from the specially Hungarian production and processing technology. Besides the traditional and highly manual labour intensive processing technology, there are some modern industrial technologies as well, where high quality can be guaranteed only by producing excellent base material (raw pepper pods). This is the reason which necessitates the rational development of the elements of the production technology, such as nutrient supply. Our objective was to offer a contribution to this aim by our trials in plant nutrition.

  Experiments on the nutrient supply of spice pepper were set up in the 2003 growing season in order to decide whether yields and fruit composition parameters of pepper could be increased by means of increased K fertiliser doses with lower N:K ratios. Several forms of potassium were used, as well as applying microelement top dressings in the single treatments. It was found that the increase of N:K ratio from I:1 to 1:6 did not increase yields, but resulted in higher pigment and dry matter content. Microelement top dressing had a yield increasing effect at each N:K ratio. Higher potassium doses did not accelerate ripening.

• Investigation of the in vitro regeneration of mericlones in the caribe variety of carnation

  87-89.

  Zs. O. Kiss

  A. Balogh

  L. Fodorpataki

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  235

  In vitro culture conditions were experimented for the relatively sensitive, but very esthaetic "Caribe" variety of carnation with uniformly dark violet flowers. Regeneration of new plants from shoot apex meristems can be significantly improved by the combined addition of very low amounts of indolebutiric acid, benzyladenine and gibberelic acid, dissolved in the Murashige-Skoog nutrient medium. Callus formation as a prerequisite for the induction of somaclonal variability can be achieved successfully with certain molar ratios between 2,4-dichlorophenoxyacetic acid and benzyladenine. Acclimation of the obtained mericlones to the ex vitro conditions was also evaluated.