Search

Search Results

• Prolonging the vase life of cut Carnation 'GIOKO' by using different chemicals

  65-68.

  O. Terék

  F. A. S. Hassan

  E. Jámbor-Benczúr

  Á. Máthé

  Views:

  396

  Cut flowers of Dianthus caryophyllus L. cv. GIOKO were treated with different concentrations of sucrose and in combination with 1­methylcyclopropene (1-MCP) to compare the effect of these treatments with floral preservative (`Spring') on the longevity of flowers. Distilled water was used for preparing all solutions. The control flowers were held in distilled water. Clorox at 2 mL^- I was added to all treatments containing sucrose and it was also applied as a separate treatment. The vase life of cut carnations was significantly prolonged due to the use of chemical treatments, as compared to the untreated control. The longest vase life (18.33 days) was obtained by using 1-MCP 0.5 g m^-3 for 6 h treatment. All concentrations of sucrose had a positive effect on flower diameter. The best treatment in this respect was 1 -MCP with 30 gL^-I sucrose. 1-MCP treatment significantly increased the chlorophyll content, as compared to the control or the "Spring" treatment. The highest values in this respect were obtained by 1 -MCP treatment alone or with the lowest level of sucrose. The effect of these treatments on the pH of solutions is discussed.

• Commercial varieties of European plums grown in Hungary, a comparison of promising foreign varieties with the widely grown traditional ones

  15-22.

  Sz. Kovács

  Á. Molnár

  Gy. Szenci

  M. Tóth

  Views:

  515

  Observations and investigations performed in laboratory at several growing sites over a period of many years are summarised on established plum varieties as well as on new promising ones concerning their marketing value. The ripening period of plum varieties was enlarged substantially with the appearance of new varieties of extra late maturity (‘Elena’, ‘Tophit’, ‘Presenta’). The new varieties did not alter the traditional colour, more or less long, violet or blue character of the plum. The most known type, ‘Besztercei szilva’ with its accustomed taste was followed by the new varieties ‘Katinka’, ‘Tegera‘, ‘Hanita’ and ‘Presenta’. The fruit size are largely of the medium category, except the early ripening small ‘Katinka’, whereas the larger and attractive (~60 g) fruits are represented by the late ripening ‘Tophit’ and ‘Empress’. The stone/fruit ratio was lowest in 3% (‘Tophit’) and 6% (‘Besztercei Bt. 2’, ‘Hanita’, ‘Jojo’, ‘ ‘Čačanska rana’) at the other end of the scale. The width and thickness of the fruit fl esh between 28 mm (‘Besztercei szilva’) and 43-44 mm (‘Empress’, ‘Tophit’). The fi rmness of the fruit fl esh excelled in the late maturity varieties ‘Presenta’ and ‘Tophit’ (~4 kg/cm2). Water soluble solids were 12-13 Brix% (‘Čačanska rana’, ‘Katinka’, ‘Silvia’) and 20 Brix% (‘Presenta’, ‘Tophit’), whereas titrated acids are found between 0.2% (‘Besztercei Bt. 2’) and 1.2% (‘Tegera’).

• Relation of sour cherry blooming dynamics and meteorological variables

  17-23.

  L. Lakatos

  T. Szabó

  Z. Szabó

  M. Soltész

  J. Nyéki

  Views:

  1172

  The aim of our research was to identify the role of weather parameters in the development of the start date and length of blooming. In order to achieve this, we examined how meteorological conditions of a particular year influence the start date and length of blooming in different years (dry, wet, cool, hot, sunny, cloudy). The meteorological parameters were the following: maximum temperature, minimum temperature, average temperature, precipitation, length of sunlight, difference of daytime and nightime temperatures, potential evaporation-PET, Huglin-index,Winkler-index, climatic water balance which can be calculated as a difference of precipitation and potential evaporation. In this study we wanted to find out whether early start of blooming results in a longer blooming period or if there is a generally faster blooming period when blooming starts later. Based on the results we can say that early start of blooming resulted in extended blooming period for three sour cherry varieties at the examined production sites. The start of blooming showed the closest relation with the difference of average daytime and nightime temperatures of the 30-day period prior to blooming. Significant relation was also detected with the thermic indexes as well as with maximum temperatures, climatic water balance and the degree of potential evaporation.We examined how weather 30 days prior and during blooming influenced the length of phases. Results showed that precipitation prior and during blooming is in significant relation with the length of blooming. We detected significant relation between daytime and nightime temperature differences and the length of blooming. The nature of the relation indicates that blooming periods were shorter in case of increasing temperature differences.We found that shorter blooming lengths occurred when maximum temperatures averaged between 13.5–14.5 ºC 30 days prior to blooming when examining the relation between blooming length and maximum temperature. If the average of maximum temperatures was below 13 ºC or exceeded 15 ºC during this period, then we could calculate with a blooming period longer than ten days. We proved that little precipitation and high temperature accelerates physiological processes, therefore we could calculate with an accelerated blooming and shorter blooming period.

• Study of Erwinia amylovora colonization and migration on blossoms of susceptible and tolerant apple cultivars

  15-19.

  E. Mihalik

  A. Radvánszky

  L. Dorgai

  T. Bubán

  Views:

  307

  The stigmata of detached flowers of susceptible and tolerant apple cultivars were inoculated with about 10⁴ gfp labeled Erwinia amylovora . There were no apparent differences in the colonization, multiplication and survival of the bacteria on the stigmatic surface of the culivars. Bacteria were washed down to the hypanthium surface 24 hours after inoculation. The visual symptoms of the infection were the discoloration and shrinkage of the floral parts. The gradual browning associated with the infection appeared first on the surface of the hypanthium followed by the discoloration of the style. The color of the filaments turned into brown only 120 hours after the inoculation. Bacterial cells were not detected in the tissues of the styles and filaments. The traits of the hypanthium surface are of prominent importance in the progression of the infection. The wrinkled surface, the convex shape of the outer epidermal cell walls with thin cuticle and the sunken stomata helped to preserve a water film for a longer period providing medium for the motility of the bacteria in the susceptible cultivar. Bacteria were restricted to small water droplets on the flat and waxy surface of the hypanthium of the tolerant cultivar and only a few were able to enter the tissues.

  Large bacterium aggregations were detected in the intercellular spaces of the parenchyma of the susceptible cultivar 48 hours after the inoculation. In the next period the Erwinia amylovora cells gradually invaded the intercellulars of the hypanthium wall, the wall of the ovary and the pedicel. Low level of bacterium aggregation was found in the intercellulars of the tolerant cultivars. It is suggested that the progression of the infection was inhibited also by physiological factors.

• Efficacy of selected botanical extracts against Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) on tomato

  31-36.

  Daniel Kepha Nabutse

  Mwanarusi Saidi

  Joshua Ogweno

  Views:

  541

  Tuta absoluta Meyrick, also known as the tomato leaf miner, is a destructive pest that feeds on tomato plants, causing significant economic losses to tomato farmers globally. Traditional methods of controlling Tuta absoluta involve the use of synthetic pesticides, but these methods have drawbacks such as environmental pollution, development of resistance by the pest, and negative effects on non-target organisms. As a result, there is a growing interest in the use of botanical extracts as alternative and safer pest control options. Three bioassay experiments were conducted to test the insecticidal, antifeedant and repellency effects of botanical extracts on Tuta absoluta. The experiments were conducted as completely randomized design (CRD) with three (3) replicates. There were eleven treatments; pyrethrum, neem, warbugia, each at different concentration levels of (8%, 10%, 12%) and controls positive (Indoxacarb 150g/L) and negative (distilled water). In all the bioassay conducted, the effects of all treatments increased over time, except for distilled water control. Synthetic chemical Indoxacarb exhibited significantly stronger insecticidal properties compared to neem, warburgia and pyrethrum extracts. Application of neem at 8%, 10% and 12% and pyrethrum at 12% had higher antifeeding effect on Tuta absoluta compared to the other treatments while warburgia at 8% concentration and indoxacarb had the lowest repellency effect compared to the other plant extracts.

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

  57-59.

  L. Lakatos

  I. Gonda

  M. Soltész

  Z. Szabó

  J. Nyéki

  Views:

  915

  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.

• Composted and natural organic materials as potential peat-substituting media in green pepper growing

  31-35.

  Sz. Jakusné Sári

  E. Forró

  Views:

  250

  Peat is the most favourable and usable medium in vegetable and ornamental plant forcing but because of the intensive exploitation peat resources decreased significantly all around the world. As peat-reserves run out the use of pine bark, composts and other organic materials spread in horticultural growing. In this study we compared the suitability of peat-based media to pine bark and two types of composts. We examined the effect of different organic materials on the growth and yield of green pepper (Capsicum annum L., variety Danubia). We found that the most developed plants were grown in peat-based media and pine bark. The average fruit weight was the highest in low moor-high moor peat mixture and pine bark. The plants which were grown in composts fell short of our expectations.

• Summer pruning of sweet cherry trees and an inquiry of winter frost damages

  41-44.

  B. Vaszily

  I. Gonda

  M. Soltész

  Views:

  9948

  One of the most demanded research projects is the intensification of fruit production. The use of dwarfing stocks is a moderate solution as their effect is scarcely satisfactory. Climatic conditions of Hungary are continental in Eastern Europe, where Atlantic and Mediterranean effects are interacting with the continentals in a kind of basin with characters of its own. Capricious meteorological episodes are often disturbing the security of development and fruiting of trees:
  • winter frosts are damaging the cambium and fruiting structures of trees
  • late spring frosts destroy cambium and flowers
  • early autumn frosts hurt the leaves
  • excessive precipitation impairs the growing fruits
  • drought periods during the summer caused water stress disturbing water husbandry.

  Vigorous stocks still prevail in the practice, and they ought to withstand challenges of weather hazards. The strong vigour of plants delaysthe process of senescence and the tendency of getting bald, and regeneration of plants is a sign of vitality. In present research, the trees have been trained on vigorous Prunus mahaleb stocks. Summer pruning was one of the important tools of intensive growing techniques. They were compared with traditional techniques and with plastic foil protected trees observing the vegetative as well as generative growth of them.

• The effect of soil coverage on the soil quality

  77-80.

  Sz. Sári

  N. Kappel

  B. Z. Sipos

  E. Forró

  Views:

  272

  In this study we carried out experiments with soil samples originated from the Haschberg variety elderberry orchard and wild-growing plants from Szigetcsép Experimental Farm.

  During the examinations we wanted to know how the black polyethene foliar soil coverage influences the quality of soil and the distribution of different nitrogen forms.

  We studied the individual covered (foliar soil coverage for every plant), the full covered (foliar soil coverage was laid in the rows) and the uncovered threatments.

  During the experiments we pointed out that the foliar coverage influences the condition of the soil unfavourably. Because of the coverage there is less air flow in soils, the lack of oxygen leads to degradating of soil life and results humus materials of poor quality.

• Study of genetic resources for Powdery mildew resistance by biochemical and physiological parameters on peaches and nectarines in Romania

  57-61.

  S. Toma

  A. Ivascu

  M. Oprea

  E. Delian

  F. Toma

  M. Zdremtan

  L. Halmagean

  L. Cantar

  Views:

  247

  During 1997-2002, studies on the physiological and biochemical changes due to powdery mildew attack in peach and nectarine cultivars and hybrids belonging to different classes of resistance had been performed at the Research Station for Fruit Tree Growing (RSFTG) Baneasa Bucharest, located in the southern part of Romania. The study was based on disease assessments in the field and on other diagnosis criteria.

  The southern part of Romania has favourable ecological conditions for growing peach and nectarine but trees have been attacked by various pathogens such as Sphaerotheca pannosa (Wallr.: Fr.) Lev. var. persicae Woronichin fungus for a long time. The presence of the pathogen causes important changes in the quantity and quality of fruits and affects the metabolism of trees.

  This study was focused on several physiological and biochemical parameters such as photosynthesis and respiration intensity along with catalase activity; and changes in some biochemical compounds such as free, total and linked water content, dry matter, nitrogen and protein content, tannin levels. The aim was to find possible correlation among the above parameters and the biotic stress induced by the powdery mildew fungus calculated as attack degree (AD%).

  Results showed that photosynthesis diminished significantly in the case of the attacked phenotypes, the respiration was more intense in the infected cultivars and catalase proved to be less intense in the affected plants. The total water content significantly increased in contrast to the dry matter and tannin contents, which greatly reduced in the case of resistant cultivars such as 'Victoria', Vectared 7', 'KB 11-40'. The total nitrogen and protein levels showed less influence on resistance to powdery mildew on all cultivars. All genetic material found resistant to powdery mildew is currently used in peach and nectarine breeding programs in Romania.

  Further studies focused on isolation and characterization of resistance genes for powdery mildew resistance will be done in the future based on data collected during several years.

• Research of the elasticity of transplant - growing substrates after watering

  67-69.

  N. Kappel

  G. Zsivanovits

  K. Tóth

  K. Slezák

  Views:

  281

  It gets more and more popular to grow transplants in different trays for the field vegetable growing. The best transplant-growing substrates in the world are made of peat. The peat is applied to provide an optimal supply of plants with water and air. To improve the water regulation and the structure of the mixtures there are often mineral matters used in different amounts. By measuring the physical properties of soil mixtures based on peat, the flexibility can be measured by Stable Micro System type table penetrometer. Our measuring confirmed the increase of bulk and flexibility of different kinds of peat by watering.

• Effects of environmental factors on morphological and quality parameters of table beet root

  139-146.

  M. Takácsné Hájos

  T. Rubóczki

  Views:

  552

  In our trial morphological and quality parameters of 15 table root varieties were tested at 3 different sowing dates: 15 April, 9 July and 19 August 2010. In the trials the root shape of the varieties form the April sowing date approached most the regular spherical shape (diameter/length –1.0) which is favoured both by fresh market and the processing industry. In the July and August sowings the roots were elongated with reduced proportions. The highest red pigment content (betacyanin) was observed in the second sowing of July (>80 mg/100 g). In the late sowing (August, under plastic tent) a further 10–20 mg/100 g pigment increase was measured in relation to the earlier sowing dates of the same varieties. A similar trend could be observed in yellow pigments (vulgaxanthis) which proves a close correlation between the quantities of the 2 pigments (r=0.823). The highest vulgaxanthin content (103.3–124.18 mg/100 g) was obtained form roots of the late sowing harvested in December. Varieties reacted differently to temperature and so to sugar accumulation in the different sowing periods. In the July sowing higher water soluble solids content was measured on the mean of varieties (10.12 %) as compared to the April sowing (7.76%). Sensory evaluations included inner colour intensity (1–5), with ring (1–3) and taste (1–5) of the raw material evaluated by scoring. According to laboratory measurements better inner colour intensity was observed in the July and August sowing dates. In these samples uniformly coloured, almost with, ring-free roots were obtained. In our trial varieties from the spring sowing had superior taste. Early sowing is recommended for fresh market sale while the second crop (July) harvested in autumn can satisfy processing requirements. In the late sowing (under unheated plastic tent) fresh beet root can be grown at the end of autumn or beginning of winter, thus prolonging the usability of plastic tents.

• Agroclimatological properties of growing sites assigned to apple and pear production in Hungary

  95-97.

  M. Soltész

  J. Nyéki

  J. Kovács

  E. Dibuz

  Z. Szabó

  Views:

  849

  Apple and pear growing sites in Hungary are classified into four regions according to the Hydro-thermic Coefficient: dry, moderately dry. moderately humid and humid. Most of the plantations of apple and pear are located in regions considered as moderately dry and moderately humid. Within that category, the two respective species have different preferences, i.e. the ecological features of Hungary give different opportunities for apple and pear growing. Apple is grown almost everywhere in the country, successfully. The selection of cultivar-regions is needed mainly for increasing competitiveness on the market. Main apple growing regions are listed in 3 large groups. For the definition of cultivar-regions, mainly the configurations of soil and precipitation, i.e. conditions of the soil and opportunities of gaining water were decisive. Market factors are also considered. The area assigned to pear is much less than that of apple, in Hungary. Some well known and popular varieties would require high air humidity which cannot be presented in most of Hungary. Therefore, the possibility to establish regions for pear varieties is restricted, we have to create a particular micro-environment. Two groups are potential. The first one comprises sites where the annual precipitation is 700 mm, at least. There, apple and pear production would compete each other. In more dry habitats (less than 700 mm annual precipitation), micro-environments should be found and only drought-resistant, mainly summer-ripe cultivars should be chosen with, preferably, low tendency of sclereid formation. In that case, neither irrigation could help to produce adequate quality in varieties sensitive to low air humidity.

   

• Jerusalem artichoke (Helianthus tuberosus L.): A review of in vivo and in vitro propagation

  131-136.

  N. Abdalla

  É. Domokos-Szabolcsy

  H. El-Ramady

  S. Hodossi

  M. Fári

  M. Ragab

  H. Taha

  Views:

  910

  Jerusalem artichoke (Helianthus tuberosus L.) is an old tuber crop with a recently renewed interest in multipurpose improvement. It is a perennial tuberous plant rich in inulin and is a potential energy crop. During food shortages in times of war Jerusalem artichoke received more attention by scientists and farmers because of its multiple uses as a vegetable, medicinal plant, forage plant and source for biofuel. The energy crisis of the 1970s motivated research on Jerusalem artichoke for biofuel as the aboveground plant biomass and the tubers can be used for this purpose. There are different methods to propagate Jerusalem artichoke using tubers, rhizomes, slips (transplants derived from sprouted tubers), stem cuttings, seeds and tissue culture. So, this review was presented to highlight on propagation of Jerusalem artichoke via in vivo and in vitro techniques.

• Analyses of the pathogen and weather components of disease progress for modeling apple scab epidemics in integrated and organic production systems

  101-106.

  I. J. Holb

  Views:

  620

  The pathogen and weather components of apple scab disease progress were analysed in a three-year study, in two environmental-friendly production systems (organic and integrated) on cvs. `Idared', `Jonica' and 'Mutsu'. Linear regression analyses of transformed disease incidence and severity data and "area under the disease progress curves" (AUDPC) were used for the analysis of the pathogen component. To evaluate the role of the weather component in apple scab epidemic, first, the weekly disease increase was determined at a certain week (n). Weekly disease increase was related to rainfall, relative humidity, Mills' wetness period, temperature and interaction between temperature and relative humidity. Five different periods were used in the analyses: i) week (n-1), ii) week n(n-1), iii) week (n-2), iv) week (n-1)(n-2) and v) week n(n-1)(n-2). In the analyses of the pathogen component, the best transformation function was the logistic one. Regression analyses showed that disease growth rates were higher for disease incidence and for the organic production system than for disease severity and for the integrated production system, respectively. Disease growth rates for leaf incidence were higher than fruit incidence on all the three cultivars. AUDPC values showed great differences in both leaf and fruit incidences among cultivars and between the two production systems. The results the of analyses of the weather component showed that the best relationships between disease increase and weather parameters were found for fruit incidence and leaf incidence in week (n-2) in the organic and integrated production systems, respectively. Results also demonstrated that in week n(n-1) temperature played a more important role in the fungus development than the water parameters (relative humidity, rainfall and leaf wetness). Consequently, infection process is significantly dependent on almost all weather parameters, but during the incubation period the most important weather parameter is the temperature. Results were compared with similar studies and biological interpretations of the analyses are discussed.

• High antioxidant - and anthocyanin contents of sour cherry cultivars may benefit the human health: international and Hungarian achievements on phytochemicals

  45-47.

  Zs. Veres

  I. J. Holb

  I. J. Nyéki

  Z. Szabó

  J. Remenyik

  M. G. Fári

  Views:

  1307

  Evidence suggests that a diet with high fruit and vegetable consumption may decrease the risk of chronic diseases, such as cardiovascular diseases 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 proved that sour cherry (Prunus cerasus L.) is a valuable natural source of some bioactive compounds important in human health preservation. According to the published data, the most important biological effects of sour cherry are connected — directly or indirectly — to their endogenous antioxidant behaviour as well as to their specific pattern of anthocyanin components. In the present work, we measured the total antioxidant capacity of some Hungarian sour cherry varieties in combination with their anthocyanin-, and vitamin-C content. In 2003, twelve clones were selected and grafted from a local sour cherry population called "Bosnyák" sour cherry grown in small home gardens and farms of the village Csengod (Great-Plain Region, South Hungary). Other Hungarian sour cherry varieties, i.e. cv. Újfehértói fürtos, cv. Érdi bőterrnő, cv. Debreceni bőterrnő, cv. Csengődi and cv. Kántorjánosi served as a control.

• New evaluation method to detect physiological stress in fruit trees by airborne hyperspectral image spectroscopy

  37-40.

  J. Tamás

  Views:

  431

  Nowadays 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.

• Anatomical relations of root formation in strawberry

  71-75.

  J. Papp

  P. Gracza

  G. Simon

  Views:

  521

  Anatomical relations of root formation are traced throughout the life cycle of the strawberry plant from the germinating seed up to the runners of the adult plant. Histological picture of the root changes a lot during the development of the plant. First the radicle of the germ grows to a main root, which makes branches into side roots and later adventitious roots are formed on the growing rootstock or rhizome. The anatomy of the different types of roots is also conspicuously different. First tiny branches appear relatively early after germination on the seedling's radicle, but soon the hypocotyl of the seedling thickens and develops side roots, which are already somewhat stronger. During this interval, the first true leaves are formed. The 4th or 5th of them being already tripartite, and the initiation of new roots extends into the epicotylar region of the shoot. The second years growth starts with the development of reproductive structures, inflorescences and runners starting from the axils of the new leaves. Near the tips of the runners below the small bunch of leaves, new root primordia are initiated. The tiny radicle of the germ develops a cortical region of 5-6 cell layers. Cells of the central cylinder are even smaller than the cortical parenchyma and include 3-4 xylem and 3-4 phloem elements as representatives of the conductive tissue. Roots originating from the shoot region are much more developed; their cortical zone contains 17-20 cell layers, whereas the central cylinder is about half as large. In the next year, new roots are formed at the base of the older leaves. These roots differ hardly from those of the last season in size and volume, however, they are recognised by colour and their position on the rhizome. The roots of the last year are dark, greyish-black, and grow on the lower third length of the rhizome, on the contrary, the new ones, on the upper region, are light brown. Roots starting from the shoot or rhizome are, independently from their age or sequence, mainly rather similar in size and diameter, thus being members of a homogenous root (homorhizous) system, i.e. without a main root. Plants developed and attained the reproductive phase develop in the axils of the leaves runners being plagiotropic, i.e. growing horizontally on the surface of the soil. The runners elongate intensely, become 150-200 mm, where some long internodes bear a bunch of small leaves and root primordia on short internodes and a growing tip. Runners do not stop growing, generally, further sections of 15-25 cm length are developed according to the same pattern, with small leaves on the tip. The growing tip of the runners is obliquely oriented, and small, conical root primordia are ready to start growing as soon as they touch the soil. The roots penetrate the soil, quickly, and pull, by contraction, the axis of the runner downwards, vertically, developing a new rhizome. The short internodes elongate a little and start developing adventitious roots. At the end of the growing season, the plantlets arisen on the rooted nods of runners are already similar to the original plants with homogenous root system. On the side of the adventitious roots, new branches (side-roots) are formed. The root-branches are thinner but their capillary zone is more developed being more active in uptake of water and nutrients. The usual thickening ensues later.

• Bacterial diseases of grapevine

  45-49.

  E. Szegedi

  E. L. Civerolo

  Views:

  746

  Grapevines are affected by three major bacterial diseases worldwide, such as bacterial blight (Xylophilus ampelinus), Pierce’s disease (Xylella fastidiosa) and crown gall (Agrobacterium vitis). These bacteria grow in the vascular system of their host, thus they invade and colonize the whole plant, independently on symptom development. Latently infected propagating material is a major factor in their spreading. Therefore the use of bacteria-free planting stock has a basic importance in viticulture. Today several innovative diagnostic methods, mostly based on polymerase chain reaction, are available to detect and identify bacterial pathogens of grapevines. For production of bacteria-free plants, the use hot water treatment followed by establishment of in vitro shoot tip cultures is proposed.

• The salt tolerance of vegetable paprika varieties

  39-45.

  K. Slezák

  I. Terbe

  N. Kappel

  K. Tóth

  Views:

  432

  In our experiments, we have chiefly tested the salt sensitivity of sweet pepper varieties. In cold forcing, 0.3 1/plant nutrient solutions of different NaCI content were given twice weekly. EC of the nutrient solutions containing 0.25% Volldünger Linz complex fertilizer was made up to 6, 10, 14 and 18 mS/cm, respectively, by 2.51/9.17/17.97/26.76 g/m² doses of pharmacopeal NaCI every week. The solution used for the control treatment contained Volldünger only (EC 4.4 mS/cm). Irrigation was made with pure water (EC 0.6 mS/cm) when necessary.

  The varieties chosen for the experiments were the following: Feherözön, HRF F₁, Syn. Cecei (of white, conical fruit), Boni (of white, blunt, infolded fruit), Titan F₁ (of pointed, hot fruit) and Pritavit F₁ (of tomato shaped fruit).

  In general, the symptoms caused by NaCI treatments (with doses higher than 10 g/m² weekly) have been the following:

  • They have reduced the leaf area, the height of the plants, the total and the early yield, the number of fruit set per square meter, the average weight of the fruit (and, in some measure, fruit length, too) and the thousand seed weight.
  • They have increased the calcium and the chlorine content of the leaves and fruits and the dry matter content of the fruits.
  • They haven't affected the dry matter content of the leaves, the nitrogen, phosphorus and potassium content of the leaves and fruits, and the germinating ability of the seed.
  • The effect on stem diameter and on seed production per fruit has been contradictory in some cases.

  The effects of the intermediate treatments haven't been explicit in several cases.

  The results of the examination of cuticular secretion have indicated the increase of the sodium and chlorine content of the leaves. This can be important in field growing where the rainwater may wash out a part of sodium and chlorine from paprika leaves.

  The hot, pointed variety and the tomato shaped paprika haven't shown clearly higher salt tolerance than the varieties of white fruit colour.

• The effect of day and night temperatures on apple skin colour formation

  21-25.

  L. Lakatos

  T. Szabó

  Z. Szabó

  M. Soltész

  S. Zhongfu

  Y. Wang

  J. Nyéki

  Views:

  1111

  The colour of fruits is considered to be an important quality indicator. Saleability greatly depends on how well covered the colour is of the specific type of fruits. It is a well-known phenomenon by growers that apples get nicer colours in one year while in other years the basically red and green colour cultivars can be differentiated only by morphological characteristic features. Cover colour is one of the phenometric variables and it is a well-known fact that significant differences can be experienced year by year. The experienced oscillation can be the cause of inappropriate water- and nutriment supply, however it can be the result of some kind of plant disease, extremely high or low temperature, setting rate above the average and outstanding fruit density. In the present examination it is postulated that the degree of cover colour is mostly influenced by day and night temperature. Therefore, our study aims to find out whether it is true or not. Cover colour belongs to those phenometric characteristic features, only the final value of which is taken into consideration; due to their nature of establishment or forming time it seems useless to follow closely the change in the time of vegetation. However, determining the start of colouring and knowing the dynamics of full colouring could carry very important information for growers. If it is possible to determine the curve describing the time change of colouring, we have a possibility to estimate it by means of enviroment variables. So it is also possible to model pigmentation in the future. Knowing this, colouring irrigation could be made more efficient in the future. For this, as a first step, it is inevitable to find out what the relationship is between the main meteorogical variables, namely day and night temperature and the difference between day and night temperature, and colour cover. In this study we summarize and show these interrelations.

• Relations of phenometrical indices of apple fruits with weather variation in the assortment of varieties of an apple gene bank

  115-120.

  L. Lakatos

  T. Szabó

  Z. Szabó

  M. Soltész

  Z. Sun

  J. Nyéki

  Views:

  949

  The purpose of phenometry is to examine the measurable parameters of the plants in order to follow up the consequences of weather processes. We should fi nd the reasons, why the diameter of fruits grows larger in one season and smaller in the next. Variation may occur as a response to insuffi cient provision of water or nutrients, but also because of pathological effects and of extremely high or low temperatures, moreover, of extraordinary heavy fruit load. There are phenometrical characteristics, which consider the fi nal consequences (density of fl owers, fruits set, drop of fruits), whereas other parameters could be followed up (size, length and width of fruits) as the dynamic components of growth. The quantitative parameters of growth are functionally related to each other, where the weather conditions, soil humidity and nutrients are on the input side, thus it is possible to model the growth of fruits as a function of the environment. Initially, the relations between the main weather variables and the phenometrical data have to be cleared. In the present study, the interactions between the mentioned phenomena are presented and numerically defi ned.

• Nutritional aspects of producing fruits organically

  69-74.

  P. T. Nagy

  J. Nyéki

  Z. Szabó

  Views:

  812

  Recent interest to avoid use of agrochemicals in fruit growing to safeguard environmental and human health has stimulated interest in organic fruit production (OFP) all over the world. Organic production requires a holistic approach to agricultural ecosystem management. Because of the perennial nature of orchards, this is not a great departure from conventional orchard management, except that corrective techniques are limited primarily to naturally derived materials. Organic mineral nutrition management hinges on two principles: 1) practices that lead to the build up and maintenance of soil that is biologically active and high in organic matter; 2) supplementing the mineral nutrients provided by the soil with fertilizers from approved sources. Organic orchards should be sited on land with superior soils and preplant soil preparation to increase organic matter and correct any sub-optimal soil characteristics. For successful organic fruit growing the following statement should be considered:Weed management is critical to reduce competition for nutrients and water. Soil and leaf analysis provide the basis for correcting mineral nutrient deficiencies or imbalances in organic production. It may be necessary to use a number of strategies to supply mineral nutrients over the life of the orchard. The slower, natural methods applied require a management approach that is simultaneously patient and dynamic.

• Chemical communication with volatile semiochemicals in Phyllotreta species (Coleoptera, Chrysomelidae): a minireview

  93-100.

  É. Csonka

  M. Tóth

  Views:

  556

  Phyllotreta species (Coleoptera, Chrysomelidae, Halticinae) rank among the most important horticultural pests in the Northern Hemisphere. Leaf damage caused by flea beetles upsets the water balance, blocks plant growth and sometimes causes a high level of mortality of seedlings. Several species are known to act as vectors of numerous pathogens as well. Chemical communication plays an important role in the host finding, feeding and oviposition behaviour of flea beetles. In the first phase volatile mustard oils (isothiocyanates and thiocyanates) are released from the host plants through the decomposition of non-volatile glucosinolates (chemicals specific to Cruciferae) by myrosinase, and beetles are attracted to the source of release from a distance. Among the isothiocyanates, allyl isothiocyanate is the longest known and widespread compound utilized in the host-plant location of Phyllotreta species, but some species may have a stronger preference to other isothiocyanates or thiocyanates. The attractive effect of the plant volatiles is enhanced by the emission of a male-produced aggregation pheromone. The presence of such a pheromone was first demonstrated in Phyllotreta cruciferae Goeze. In this species R5R,5aS)-1,1,5,8-tetramethy1-1,2,3,4,5,6,5a-heptahydrobenzo[1,2-a][7]annulene] was found to be the main pheromone component. Significant attraction by the pheromone was recorded only in the presence of ALLYL ITCN. The biological activity of the pheromone compound was connected to the plus (+) chirality. The same component seems to be occurring also in the pheromones of several other Phyllotreta spp. as well, suggesting a wider occurence in the genus. Once attracted by the joint effect of plant volatiles and aggregation pheromone, the presence of the non-volatile glucosinolates in the plant tissues is necessary for continuous feeding. Aggregations of flea beetles on suitable host plants, which result from the joint effects of plant-derived and pheromonal chemical cues detailed above may also be good rendez-vous occasions, increasing the probability of encounters with the opposite sex and mating in the vicinity of the optimal oviposition site. Due to the horticultural importance of Phyllotreta spp., deciphering details of their chemical communication has considerable significance in the development of new methods of integrated control.

• Colour components of different table beet varieties

  36-38.

  M. Takácsné Hájos

  Views:

  401

  Information of the total pigment content of table beet roots is not sufficient enough to estimate their suitability to processing. Differences in the occurrence of the red pigment components of different thermostability determine the mode of processing of the varieties. Pigment extraction methods which require heat treatment (e.g. table beet root powder) need raw materials of higher betanin content.

  Of the tested varieties — Bonel, Nero, Favorit, Rubin and Detroit — Bonel and Favorit had the highest betanin content (50.03 and 49.53 mg/100g, respectively).

  The isobetanin quantity varies according to varieties (13.10-26.62 mg/100g). Values between 2.92-6.63 mg/100g and 0.96-2.96 mg/100g. respectively were found for betanidin and isobetanidin.

  Data revealed the highest BC/BX ratio in the variety Rubin (2.08) indicating good inner colour in sensory tests. However, the high total pigment content (81.01 mg/I00g) was associated with lower betanin content (46,26 mg/100g) and at the same time, with higher isobetanin (25.16 mg/100g), betanidin (6.63 mg/100g) and isobetanidin (2.96 nig/100g) contents. Out of the tested varieties Nero had the lowest total red pigment content (57.43 mg/100g) but the relative betanin value was the highest with nearly 70 %.

  Laboratory testing of the table beet root varieties will be required to find the most suitable material to produce colouring agents.