Search
Search Results
-
Eicosapentaenoic acid production by Phaeodactylum tricornutum under different culture condition
133-136.Views:224Phaeodactylum tricornutum UTEX 640 strain of microalgae was screened under different culture conditions for their capacity to produce eicosapentaenoic acid (EPA) the most abundant polyunsaturated fatty acid (PUFA). In our experiments, the effect of sodium chlorid, nitrogen source, phosphate, initial pH, as well as the CO2 content of the medium on production of the eicosapentaenoic acid (EPA) by P. tricornutum were investigated. The EPA content of biomass was enhanced by the low pH of the medium, with increased concentrations of B17 vitamin and nitrate, and also with decreasing concentrations of sodium chlorid. The EPA is most likely associated with polar (membran) lipids and the role of EPA appears to be involved with membran permeability in microalge. The synthesis of phospholipids, enhances the EPA content of the cells, as expected. The maximum EPA yields were observed under optimum culture condition 43 — 48 mg/g of dry cell weight.
-
Effects of irrigation frequency and repellent plants on false codling moth (Thaumatotibia leucotreta) infestation, growth, yield, and quality of sweet pepper (Capsicum annuum L.)
34-40.Views:95Sweet pepper (Capsicum annum L.) is an important vegetable and spice crop grown worldwide for its pungency, which is derived from high concentrations of capsaicinoids. Despite the economic importance of sweet pepper as an export vegetable in Kenya, its production is currently constrained by the false codling moth (FCM) (Thaumatotibia leucotreta) and inadequate management strategies for the pest, among other factors. This study, therefore, evaluated repellent plants (Artemisia (Artemisia absinthium), Lavender (Lavandula angustifolia), and Spearmint (Mentha spicata) under different irrigation frequencies to control FCM. A split-plot factorial greenhouse experiment was conducted at Kenya Agricultural and Livestock Research Organization, Muguga (trial 1) and the Horticulture Research and Teaching Field, Egerton University, Kenya (trial 2). Irrigation frequency at three levels (irrigating once a week, irrigating twice a week and irrigating thrice a week) was the main-plot factor, while repellent plants at four levels: sweet pepper (Capsicum annum L.), artemisia (Artemisia absinthium), lavender (Lavandula angustifolia) and spearmint (Mentha spicata) constituted the sub-plot factor. Irrigating thrice or twice a week and using lavender as a repellent plant significantly reduced false codling moth infestation by 90%, increased yield by 28% and improved fruit quality in terms of fruit collar diameter and total soluble salts (TSS). The findings demonstrate that integrating lavender repellent plants with frequent irrigation can be adopted as an eco-friendly management strategy for FCM and enhancing sweet pepper yield and quality.
-
Hungarian apple growing and marketing on the doorstep of the European Union
15-18.Views:233The 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.
-
Evaluation of vermicompost application and stress of dehydration on mullein medicinal plants
69-77.Views:339The use of organic fertilizers is one of the suitable solutions in the organic production of medicinal plants due to its good effect in improving soil properties, reducing environmental effects, and better plant growth. To investigate the effect of vermicompost organic fertilizer application and water stress on some morphological and physiological traits of the Mullein medicinal plant, research was conducted at Isfahan Azad University in the form of split plots in the form of a randomized complete block design with 4 replications. The test factors included the application of vermicompost organic fertilizer at three levels of 0, 4, and 8 kg per square meter of soil and water stress at two levels of normal irrigation and irrigation at the time of 50% of the soil's agricultural capacity as the main treatment in research farm conditions. The results of the experiment showed that the application of vermicompost organic fertilizer and water stress improved the morphological and physiological characteristics of the Mullein medicinal plant compared to the control, i.e. no application of organic fertilizers. The results showed that the highest number of secondary branches, number of flowers of the secondary stem, diameter of flowering stem, the diameter of flower, and fresh weight of shoot in the Mullein medicinal plant were obtained by applying vermicompost organic fertilizer at the rate of 4 and 8 kg of soil. The application of vermicompost organic fertilizer at the rate of 8 kg in the soil increased flavonoids compared to the non-use of vermicompost treatment. However, to improve the vegetative growth and increase the reproductive efficiency of the Mullein plant and reduce production costs, the use of vermicompost organic fertilizer is recommended at the rate of 4 and 8 kg of soil, respectively.
-
Drought stress monitoring by laboratory and satellite spectral methods in an apple orchard
7-9.Views:468An orchard can be examined on the basis of spectral data, using such methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Based on the spectral characteristics of the canopy, or the different index numbers calculated from hyperspectral data the water supply conditions of foliage can be well characterized. The research site is an intensive apple orchard, which located in Debrecen University, Centre for Agricultural and Applied Economic Sciences, Farm and Regional Research Institute at Pallag. During our experiments the evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by drought. Furthermore, MODIS NDVI time series data were analyzed for orchards situated in North-Eastern part of Hungary in drought effected and wet years in order to detect differences. Significant differences in NDVI values were detected after the end of June.
-
Flower microphenology of Hungarian sour cherry cultivars in Iran climatical conditions
99-101.Views:1078Determination of flower microphenology for selecting the suitable pollinizer for sour cherry cultivars is of significant importance. In order to study the flower microphenology of Hungarian sour cherry (Bőtermő, Érdi jubileum and Cigány) cultivars in Mashhad climatic conditions, an experiment was conducted in I998. 1999, 2005 and 2006, using a completely randomized design with ten replications. The phenological stages were determined from before opening up to browning phase of stigma. Duration of pollen shedding, stigma receptivity and climatic factors were measured. The relative time of flowering between cultivars varied from year to year. The data indicate, the thermal variation strongly contributes to significant differences in duration of stigma viability, although there wasn't a significant difference between cultivars in anther dehiscence period. Phenological stages of flowers are highly affected by meteorological factors in various years.
-
Effects of different rootstocks on the morphologic parameters of watermelon grafts during transplant production
69-73.Views:376Before Hungary joined the EU watermelon production was a key sector of the Hungarian vegetable industry. Its production area shrank by nearly 60 % since 2004, it is only 5000 ha today. Stable and reliable market failed to evolve in the last years and extreme weather events occurred more frequently. An unfavourable growing season can notably affect the production volume of the next season. Information gathered in the last years support the assumption, that suitable stocks can help eliminate the issues caused by extreme weather or short-term crop rotation. Choosing the right grafted or non-grafted transplant is not enough any more, growers also have to select stock. In fruit and vine production choosing the stock, which is the most suitable for the technology is evident and this approach should be widely adapted by watermelon growers as well. In this research we investigated the growth parameters of different watermelon stocks and their effect on the scion during the transplant production. Measurements were carried out on seven different stock-scion combinations of the scion ’Topgun F1’ hybrid. Two of the stocks were interspecific (Cucurbita maxima × Cucurbita moschata) and five stocks were Lagenaria-type (Lagenaria siceraria) stocks. We made and recorded observations of the transplants’ length (cm), diameter of the stock and scion (mm), number of leaves (piece), root length (cm), root mass (g) and shoot mass (g). We concluded that early pricking out of transplants with interspecific stocks is successful due to their hardiness and vigorous growth. The effect of the ’Shintosa camelforce F1’ interspecific stock was outstanding. Furthermore, the results confirmed the practical observation that the root system of interspecific stocks grow vertically more allowing them to take up water and nutrients from lower soil layers in poor sandy soils. From the Lagenaria group the root system of the ’DG-01 F1’ was similar to the interspecific stocks’. It can be grown even in sandy soil, however other Lagenaria-type stocks are more suitable for production in hard soils with nutrient supply because of their compact root system. This study can serve as a basis for further research in the topic that can conduce to site- and technology-specific stock selection.
-
Studies on the drought responses of apple trees (Malus domestica Borkh.) grafted on different rootstocks
29-36.Views:1390The morphological and chemical changes in the leaves of eight apple varieties grafted on M4, M26 and MM 106 rootstocks were examined during fruit development in non-irrigated plantation. The aim of the experiment was to examine the defensive mechanisms in apple trees under the mild and serious dryness occurring during fruit development. The content of a relative chlorophyll (SPA D value) of the apple leaves on eastern side of the trees was lower than western and southern sides under drought occurring du ring fruit devclop111ent Under sustained drought from first of July to August the SPAD value, the weight of leaves were larger and the stomata density was significantly larger than in the previous periods. There was a close positive significant correlations bet ween SPAD and stoma density both in the group with less sensitive to drought (r=0,8429) and in the large water demanded group (r=0,9209) equally. The rate of increase in SPAD values and the stoma density was slower in the group with drought tolerant, than in the group required good water supply. The varieties being sensitive to water deficite such as Akane. Pink Lady and Red Rome van Well have a l ready responded intensively to short time of drought by the increasing of carbohydrate and antioxidants product ions. At 42 days of sustained drought as soon as the level of carbohydrate in the leaves decreased, the antioxidant s contents of the leaves rised suddenly in the apple varieties with moderate water requirement s as Greensleeves and ldared. Gala apple variety seemed to be able to defend the drought for longer time because there was no change in relatively high level of carbohydrates and antioxidants of their leaves under severe drought during fruit development.
-
Down-regulation of ethylene production in carnation (Dianthus Caryphyllus L.) by an apple derived ACC-cDNA
101-104.Views:250Transgenic carnations were produced with an apple derived antisense ACC-synthase cDNA. Transgenic carnation regenerants were potted in glasshouse. All transformed plants showed normal growth and were true-to-type. Ethylene production — measured at full opening stage — lowered by 30-60 %, no plant with 100 % decrease was identified. The vase-life has been observed for 5 years. 38 % of the transformant carnations showed a higher a relative value in days by more than 2 days to 6 days. Twenty six plants were found exhibiting the most marked alterations in the tested trait. In these plants ethylene production decreased by 37-67 %, they have longer vase-life (by 4 days or more). Since the fragrance variety 'Bíbor' was the plant material for genetic modification of vase-life, this trait has been conserved after transformation in spite of the fact that the position of transgene integration cannot be directed.
-
Evaluation of biological control option for Bagrada bug (Bagrada hilaris (Burmeister)) in Kenya
43-47.Views:284Brassica production is important for economic development of Kenya. Bagrada bug, a significant pest of brassicas, affects their yields and quality, currently posing a threat to both local and commercial vegetable production in Kenya. Biological control of bagrada bug using natural enemies is a cheaper and environmentally friendly method. The study aimed to identify native egg parasitoid species in Kenya. A field prospection survey of the bagrada bug egg parasitoid was done by a series of bagrada bug egg exposure in different parts of the country. Freshly laid bagrada bug eggs in cards were exposed for possible parasitism in the field for three days. The eggs were later carried to the laboratory at NSRC to await hatching. Two egg parasitoid species Trissolcus basalis (Hymenoptera, Scelionidae) and Gryon sp. were identified during the study after a period of bagrada bug egg exposure in Machakos and Kisumu. Two cards with parasitized bagrada bug eggs were recovered from Machakos from which one card yielded four parasitoids of one species Trissolcus basalis and the other yielded two parasitoids Trissolcus basalis and Gryon sp. One card with two parasitized eggs by Trissolcus basalis was recovered from Kisumu, however, there were no parasitoids identified in Nanyuki, Naivasha and Kitengela where bagrada bug is also prevalent. Results showed parasitoid presence in fields with high bug populations compared to areas with few or no Bagrada bug infestations. Conducting trials in both laboratory and field settings is recommended to obtain clear data on the effectiveness of the identified egg parasitoid in managing the bagrada bug population.
-
The role of insurance in the damager mitigation of fruit orchards
117-122.Views:300Hungary faced many natural disasters in 2007. Due to the estimation of the Hungarian Chamber of Agriculture, the amount of natural disasters that occurred in Spring 2007 (frost, hailstorm and drought in April and May) is about 100 billion HUF. Frost and drought caused damage on about 250 thousand hectares of arable land. Currently, there are four insurance companies dealing with agricultural insurances in Hungary. Their income was nearly 20 billion HUF in 2003, whereas it barely exceeded 6.6 billion HUF in 2004. The reason behind the significant decrease of insurance fee is the state provision made in 2004 stopping fee subsidisation which originally started in 1996, enabling farmers to require a 25-30% reimbursement of the amount paid for insurance. Launching a state subsidisation again would greatly increase the number of agricultural insurances. The law about the national agricultural mitigation system passed last Autumn. This provision declares that the mitigation of agricultural damage that cannot be insured on a business-like basis is based on the common risk-taking by the state and the farmers. The introduction of this system is explained by the fact that the mitigation of damages through disaster can only be carried out if those affected also take part in it, according to EU rules.
-
Possibility of modernization of Ganoderma lucidum strains substrate
55-57.Views:217Ganoderma lucidum (Reishi mushroom), the object of our experiments, is also known to contain medicinal compounds. This fungus has been used for many centuries as medicine in China. The fruiting body of the fungus contains carbohydrates, amino acids, little protein, fat, alkaloids, vitamins and minerals. Two groups of its substances are reported to be effective particularly. One of them is constituted by the polysaccharides, whose antitumor and immunostimulating effects are well demonstrated, and the other is constituted by the triterpenes. The latter include ganoderic acids, ganolucidic acids and lucideric acids. These acids have been reported to suppress liver hyperactivity (Lelley 1999). The experiment was carried out with 8 Reishi mushroom strains in 3 repetitions. Experiments were performed on 3 different substrates The spawn run period took approximately 2 weeks, the first fruiting bodies appeared on the 33rd day from inoculation, but the formation of the fruiting bodies took almost 70 days on the different substrates. Spawn run presented a diversified picture as influenced by the specific substrates. No spawn run was seen with any of the strains on the substrate composed of 100% wheat straw. Among the strains the fastest spawn run was produced by GA02 and GA06. The earliest start of spawn run was registered for substrate 1 after 1 week.
-
Some flower characters, variety features and environmental effects affecting bee pollination of pear (Pyrus communis L.): a review of the results of latest research
59-66.Views:344Intensive research has been implemented on different aspects of the bee pollination of pear in Hungary in the past decade, extending to the following topics: the effect of the opening sequence of the flowers within the inflorescence of pear cultivars on the effectiveness of bee pollination; the nectar production of flowers of pear cultivars; intensity of honeybee visitation and their foraging behaviour at the flowers of pear cultivars; flower constancy of honeybees to pear plantations; competition by weeds in bloom for bee pollination in flowering pear orchards; and some aspects to the bee pollination strategies of pear plantations (the effect of the limitation of bee pollination period on the set and the yield, possible compensation of frost damage of flowers by bee pollination in pear orchards, the optimal size of single cultivar block in pear plantations). The results of these studies are reviewed in this paper and some important aspects that need further studies are outlined.
-
Effects of wastewater irrigation on soil physico-chemical properties and vegetables quality: A review
7-16.Views:699This study analyses the use of raw urban wastewater for irrigation and its effects on soil characteristics and heavy metal pollution within crops. There is rampant use of urban waste water by small scale urban vegetable farmers in Zimbabwe. This is posing health hazards to the consumers of urban vegetables and decrease in soil functioning. The significance of this study was to appraise the research study related to the use of urban waste water to answer the research question: What is the impact of waste water on selected soil physico-chemical properties and quantities of heavy metals in vegetables irrigated with waste water? A systematic review of 3100 articles from PubMed, Scopus, Web of Science, and Google Scholar (2010–2024) was performed within PRISMA guidelines. After excluding irrelevant studies, 49 from Nigeria, Bangladesh, Iran, Egypt, India, Pakistan, China, Saudi Arabia, and DRC were selected for analysis. These countries were found to have a lot of literature on urban waste water irrigation. This literature review identified an overview of existing literature on urban waste water irrigation and synthesise findings to provide a comprehensive overview of the topic The results showed (P<0.05) soil properties changed significantly: pH (6.0–7.0 to 4.5–5.5), electrical conductivity (0.2–0.4 to 1.5–2.0 dS/m), organic matter (2–3% to 4–6%), cation exchange capacity (10–15 to 20–25 meq/100g) all aligning with the intended outcomes. The level of nutrients (N, P, K) shifted alongside the source of wastewater. Soil also accumulated heavy metals (Zn, Cd, Pb, Fe, Mn, Cu) while the crops accumulated unsafe levels of Pb (2.5 mg/kg), Cd (1.2 mg/kg), and Cr (3.1 mg/kg) which surpassed WHO/FAO limits. The results highlighted the concern for health and environmental hazards. Treatment of the wastewater, monitoring of the soil, and stricter guidelines are needed for safe agricultural practice.
-
Relationship between several meteorological factors and phenological features of pear cultivars
67-73.Views:1125The aim of this paper was to investigate the fl owering characteristic of apples and their relationship to meteorological parameters. The trees observed are grown at Újfehértó, Eastern Hungary in the plantation of an assortment (gene bank) with 586 apple varieties. Each of the varieties 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 90th and 147th day of the year over the 18 years of observation. The early blooming varieties start blooming at 10–21April. The varieties 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 infl uencing the start of bloom in the subsequent spring.
-
New sour cherry cultivars selected from local sources
79-80.Views:591New sour cherry cultivars selected from local sources
-
High antioxidant - and anthocyanin contents of sour cherry cultivars may benefit the human health: international and Hungarian achievements on phytochemicals
45-47.Views:1286Evidence 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.
-
The effect of different carbohydrates on the multiplication of Hosta cultivars
115-117.Views:370The effect of seven concentrations of two carbohydrate sources were compared to determine the best source and the most suitable source and concentration for micropropagation of some Hosta cultivars: H. 'Gold Haze', H. 'Gold Drop' and H. 'Dew Drop'. 0, 5, 10, 20, 30, 40 and 50 g/1 sucrose or glucose were added to a MS basic medium supplemented with 3 mg/1 kinetin and 0.1 mg/1 IAA. For 'Gold Haze' 40 g/1 sucrose proved to be the best source and concentration, the proliferation ratio was 15 shoots per explant. Thirty g/1 sucrose concentration was the optimum for 'Gold Drop', the proliferation rate was 14.6 shoots per explant. In 'Dew Drop,' the best results were obtained with 30 g/1 sucrose but 40 g/l sucrose gave good results too. Both cultivars rooted well on these media. On glucose containing media, very low propagation rates were found in all concentrations and all examined cultivars.
-
Sex expression of flowers in cultivated sweet and sour cherries
50-52.Views:353During 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.
-
Genotypic difference of garlic (Allium sativum L.) cultivars for growth, bulb yield and yield related attributes at Tigray Province, Northern Ethiopia
46-52.Views:347The experiment was conducted at Ofla district from June to October of 2017 and 2018 cropping season to select high yielding and adaptable garlic cultivar(s). Six garlic cultivars namely Chefe, Tsedey, Holeta local, Kuriftu and Bora-4 and one Ofla Local were evaluated. The experiment was arranged in completely randomized block design (RCBD) with three replications. Different growth, phenology, yield and yield related data were collected. Leaf length, leaf width, bulb diameter and length were significantly (p<0.05) influenced by garlic cultivars in both cropping seasons. Bulb weight and number of cloves per bulb were highly significantly (P<0.01) influenced by cultivars in both cropping seasons. Also, marketable yield, unmarketable yield and total yield ha-1 were highly significantly (P<0.01) influenced by cultivars in both seasons. During 2017 and 2018, the highest marketable bulb yield was observed from Ofla Local cultivar with an average value of (8.86 t/ha) and (9.06 t/ha) respectively. During the 2017 cropping year, the maximum and significantly higher total bulb yield of 10.21 t/ha was recorded on the Ofla Local cultivar. Moreover, in 2018, this cultivar provided the maximum total bulb yield of 9.80 t/ha. Therefore, the Ofla Local cultivar showed the greatest performance for growth, yield and yield related attributes. Thus, it is recommended for cultivation in areas having similar agro-ecology. To improve the productivity of garlic, it is important to study and identify the optimum fertilizer level and spacing in the study area.
-
Estimating of water consumption of cherry trees
15-17.Views:398Despite 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- 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.
-
Virus and virus-like diseases of grapevine in Hungary
25-36.Views:459Viruses 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.
-
The effect of potassium fertilization on the inner values of spice pepper
27-29.Views:328To 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.Views:305Current 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 MaryblytTM 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.Views:1066Bud 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.
