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• The increasing importance of grapevine trunk diseases

  21-30.

  Cs. Kovács

  E. Sándor

  Views:

  514

  Grapevine trunk diseases (GTDs) are destroying the woody parts of the plants, resulting decline or dieback of the grapevine. More detailed research of the GTD began in 1950s, when Hewitt et al. (1957) observed that specific symptoms cannot be detected on the diseased trunks every year. Latest results have also proved that abiotic factors affect the appearance and the severity of the disease. Moreover several pathogenic fungi may play role as causative agents (Bertsch et al., 2013). Eutypa, Botryosphaeria, Phomopsis dieback, esca disease complex, and Petri disease are considered the major GTDs, where a variety of pathogens attack the woody perennial organs of the vine and ultimately lead to the death of the plant (Lehoczky, 1974; Larignon & Dubos, 1997; Rolshausen et al. 2010; Kotze et al., 2011; Bertsch et al., 2013; Fontaine et al., 2015).
  The GTD incidence has been reported to be increased during the last decades (Úrbez-Torres et al., 2014). The esca incidence has reached 60% to 80% in some old vineyards in southern Italy (Pollastro et al., 2000; Surico et al., 2000; Calzarano & Di Marco, 2007). The disease incidence of the esca was reported to be increased from 1.83% to almost 13%, between 2003 and 2007 in Hungary (Dula, 2011). There was detected a five times increase in the GTD disease incidence in the Tokaj Wine Region, Hungary between 2014 and 2016 (Bihari et al,
  2016).

• Volumetric estimation of an intensive apple orchard with GIS

  7-10

  P. Riczu

  É. Bozsik

  B. Gálya

  J. Rásó

  I. Csiha

  A. M. El Shal

  J. Nyéki

  J. Tamás

  Views:

  873

  Remote sensing instruments and methods have become widespread in all segments of agriculture and horticulture. Among the innovative development of remote sensing instruments, the 3D laser scanner is one of the newest technique, which overtop in the spatial data collection. Terrestrial laser scanning is an appropriate tool for identifying such biophysical parameters like the structure of trees and branches, growth of volume. Determination of these parameters are time consuming and complicated with traditional methods. The examination was carried out in the Study and Regional Research Farm of the University of Debrecen near Pallag. We used Leica ScanStation C10 terrestrial laser scanner to estimate volumetric properties of the intensive apple orchard. Two rows of the study area were surveyed, where the height and stem diameter of apple trees were measured with Geomagic Studio 12 GIS Demo Software. Based on the built-in algorithms, the volume of each tree were defined by the software. The measured and calculated data was correlated, and middle correlations were detected. Estimated volume results could be useful for further investigation such as CO2 fi xing, which is an important factor for ecological service of the plantation.

• Fungicide resistant Trichoderma strains causing compost infection in shiitake production

  67-70.

  Gy. Turóczi

  M. Kovácsné Gyenes

  L. Vajna

  S. Balázs

  Views:

  233

  Trichoderma infection represents the major problem of shiitake production in the growing house of the Research Institute at Kecskemet. Heavy infections occur mainly on the compost before spawn run. All the isolated strain belongs to the species Trichoderma harzianurn, but morphology of the colony indicates that there are more strains liable for the infection. Source of infection remained unclear but the Trichoderma strains can be considered as weed moulds rather than true pathogens of shiitake. All the Trichoderma isolates showed unusual high degree of resistance to fungicides.

• Effects of different cytokinins on the shoot regeneration from apple leaves of 'Royal Gala' and 'M.26'

  69-75.

  J. Dobránszky

  I. Hudák

  K. Magyar-Tábori

  E. Jámbor-Benczúr

  Zs. Galli

  E. Kiss

  Views:

  447

  The effects of different types of cytokinins on the shoot regeneration from leaf explants of apple scion 'Royal Gala' and apple rootstock 'M.26' were evaluated. Regeneration media contained either thidiazuron, or 6-benzylaminopurine, or meta-topolin, or zeatin, or kinetin, or their N⁹-ribosides, respectively, in the concentration range 0.5 to 8.0 mg 1^-1. Effects of 'these cytokinins were evaluated on the percentage of regeneration (R%) and that of vitrification (V%) and on the number of regenerated shoots per explant (SN). Organogenetic index (0I) calculated from these data was used for the evaluation of efficacy of cytokinins. The course of shoot organogenesis also was followed using stereomicroscope. Types and concentrations of cytokinins applied in the regeneration media influenced each parameter significantly and the regeneration answer was strongly genotype-dependent. The best regeneration (SN: 11.08, 01: 7.5) was achieved in `Royal Gala' by using TDZ in concentration of 0.5 mg 1<sup>-1</sup> (2.271,1M). There was a clear relationship between the effect on the regeneration efficacy and the chemical structure of cytokinins considering classical cytokinins, namely N<sup>9</sup>-ribosides applied in less concentration than non­ribosides have the same or best regeneration effects except for 6-benzylaminopurine riboside. However, similar relationship could not be detected in the case of 'M.26'. SN was the highest (3.22) using 6.5 mg 1<sup>-1</sup> (18.2011M) 6-benzylaminopurine riboside or 8.0 mg 1<sup>-1</sup> (21.44 µM) meta-topolin riboside (3.18). SN was not significantly lower (3.12) by using 2.0 mg 1<sup>-1</sup> (9.08 1M) TDZ, however, OI was about half as big (0.63 compared to 1.29 or 1.74 with 6-benzylaminopurine riboside or meta-topolin riboside, respectively). 'Royal Gala' had higher organogenetic ability, than `M.26': 3.5-fold higher shoot number per explant and more than 4-fold higher organogenetic index was reached with this cultivar than with 'M.26'. Moreover, the similar developmental stage of shoots could be observed 3-5 days earlier than in 'M.26' and if explants of 'Royal Gala' were further cultured with 3 weeks, SN increased from 11.08 to 24.42 on TDZ-containing regeneration medium, which might suggest higher organogenetic ability, too.

• Preliminary data on attractiveness of phenylacetaldehyde-based lures on economically important plant bug pests (Hemiptera: Miridae)

  87-94

  T. Szalárdi

  A. Nagy

  F. Oláh

  M. Tóth

  S. Koczor

  Views:

  739

  Several plant bug species (Miridae) are important pests of crops and vegetables, thus monitoring them is of essential importance for effective pest control. During the current, preliminary study synthetic plant volatile combinations were tested in field conditions in Hungary in alfalfa fields. Beside semiochemical baited traps, sweep-netting was also performed. In the experiments three plant bug species were found in higher numbers: Adelphocoris lineolatus, Lygus rugulipennis and L. pratensis. As a novel, interesting finding L. pratensis was attracted to phenylacetaldehyde baited traps. For all species, both males and females were trapped in all combinations. Sweep-netting and semiochemical baited traps showed different efficacy in case of the three species, as sweep-netting catches were highly biased for A. lineolatus, which indicates the higher efficacy of this method as compared to the tested semiochemical-baited traps. On the other hand, semiochemical baited showed better performance for L. rugulipennis and L. pratensis. For these species none of the tested combinations performed better than phenylacetaldehyde baited traps. The potential implication of results in view of monitoring are discussed.

• Carotenoid composition and content in products of sea buckthorn and peach as determined by high-performance liquid chromatography

  69-74.

  H. G. Daood

  K. Solymos

  D. Bánáti

  Z. Berta

  J. Nyéki

  Z. Szabó

  Views:

  1112

  A study was conducted to analyse the carotenoids by high-performance liquid chromatography (HPLC) using reversed-phase cross linked end-capping and to study the pigment content and composition in sea buckthorn products as well as in freshly harvested fruits from peach thees grown under organic and integrated farming conditions. It was found that carotenoids in fruits of both crops occur mainly esterified with fatty acids in form of mono- and di-esters. The major carotenoids were esters of zeaxanthin, lutein, β-cryptoxanthin and β-carotene. The major carotenoids showed different response to processing of sea buckthorn being highly sensitive to thermal treatments such as blanching, cooking and drying. Significant differences were found between peach varieties in their carotenoid content, whereas the impact of organic farming on carotenoids formation was found to be variety-dependent. Two of the three varieties examined in this work, when cultivated under organic farming conditions contained lower carotenoid level as compared to that found in the fruits of the same varieties but produced in integrated farms.

• Comparative study of sour cherry samples for their anthocyanin content measured by tools of the laboratory and by portable equipments

  29-31.

  G. Szemán-Nagy

  G. Pintér

  J. Prokisch

  J. Tornyai

  J. Nyéki

  Z. Szabó

  T. Szabó

  M. G. Fári

  Views:

  917

  The inner quality of fruits depends on many components. The analysis of pharmacologically important fruit species as the sour cherry consumed as a common food is an expensive task, mostly requiring an equipped laboratory. In sour cherry, one of its valuable components, the anthocyanin content deserves special attention. A portable analytical implement, which has been developed by our team measures the anthocyanin content on a scale of 1024 PharMgrades. The system is a member of the UVEX family of implements working with a microprocessor and performs the measurement quickly. The portable variant (UVEX-ML-1) does not require much training, the laboratory variant (UVEX UL-1) performs a large quantity of tests under modest laboratory conditions. Preparation of the samples is easily done, the necessary elements are available in the trade. The reagent is easily stored and dosed. The system was tested and proved to be of sufficient precision and the result showed acceptable variance according to the checks performed by a spectrophotometer in the laboratory.

• Colour and water content detection of sweet cherry by portable spectrometer

  23-26.

  A. Nagy

  J. Tamás

  M. Soltész

  J. Nyéki

  Z. Szabó

  Views:

  35464

  Based on the most recent data, the average amount of sweet cherry produced in Hungary is around 10-12 thousand tons. Therefore fast and effective method is important for sweet cherry fruit quality analyses. The aim of the study was to examine the applicability of reflectance measurements for sweet cherry fruit quality analyses. In our experiment five cherry species (Vera, Cristalina, Germersdorfi, Noir de Mechet, Canada Giant) were examined in order to measure the spectral differences between species. Further more, spectral alteration was examined between different health and maturity status of the fruits in the case of a specified, the Germesdorfi species. The four new indices are appropriate tools for cherry quality analysis. Thus reflectance measurements can also support more precise and automated fruit selections. The methods for the differentiation of species could also be viable at a concerned habitat; however, the climate, habitat and soil conditions strongly affect the yield quality. Concerning the fast determination of water content, WBI could be a reliable method for the assessment

• Clonal selection of black locust (Robinia pseudoacacia L.) in Hungary: a review

  153-56.

  K. Rédei

  Z. Osváth-Bujtás

  Zs. Keserű

  Views:

  370

  Black locust (Robinia pseudoacacia L.) is the most important fast growing stand-forming tree species in Hungary. Its importance is increasing in many other countries, too. As a result of a new selection programme 13 black locust clones have been improved for setting up clones trials and seed orchard. In 2003 five of them (R.p. `Bácska', `Homoki', 'Szálas', `Oszlopos' and `Vacsi') were registered as cultivar­candidates. Tissue culture method has proved as a suitable mean of propagating superior individuals. The micropropagated plants have been growing successfully in the clone trials.

• Water consumption of the wine grape varieties Kövidinka K.8 and White Riesling B.7

  25-30.

  E. Hajdu

  E. Miklós

  Gy. Gábor

  Views:

  238

  In the Carpathian Basin Kövidinka and White Riesling are promising wine grape varieties. As in the region continental climate dominates and dry years are not uncommon it was natural to study the water requirement and consumption of the two varieties. Morphological characters affecting transpiration were observed including leaf area, hairiness, number and type of stomata. The amount of water transpired per unit leaf area and time and rate of water consumption were measured in a model trial in cuttings with known water supply.

  The water consumption of vine cuttings depends on varieties and is determined by the genotype but it is also affected by environment. Kövidinka requires little water and uses it to its advantage White Riesling requires more water and uses it rather lavishly. The results of our model trial could be introduced directly into viticulture practice.

   

• Seasonality of weather and phenology of reproductive organs of flower of sour cherry cultivars in Hungarian climatic conditions

  75-80.

  H. G. Davarynejad

  M. Ansari

  T. Szabó

  J. Nyéki

  Z. Szabó

  Views:

  820

  Sour cherry (Prunus cerasus L.) is one of the most important fruit crop grown in Hungary, The flowering phenology and pollen shedding/stigma viability ratio, in an effort to elucidate the reproductive phenology of nine economically important sour cherry cultivars (Érdi bőtermő, Debreceni bőtermő, Csengődi, Kántorjánosi 3. Pándy 279. Úfehértói fürtös, Petri, Éva, and Oblacsinszka) all widespread in the Hungary, was studied at Újfehertó climatic condition. The main aims were to investigate how possible environmental cues influence timing and development of phenophases and whether different cultivars have different seasonal responses to these cues. Likely effects of climatic changes on phenological development patterns were also considered. Our results revealed important aspects of the reproductive biology of sour cherry flowers. The amplitude of the phenophase "beginning of blossoming" between cultivars did not exceed 6 days. There is maximum 3 days difference in blooming length of different direction in each cultivar. Pándy 279 showed high variability when the position of flowers changed on the tree shoots. Újfehértói fürtös was stable in all four directions of tree. The pollen shedding period and stigma viability ratio was well synchronous. Pollen shedding phenomenon occurred in the range limitation of secretary activity of stigmas in all five cultivars. Distribution of pollen shedding over the secretary activity of stigmas is almost good. In all five cultivars maximum pollen shedding occurred about the high temperature part of the day.

• 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:

  244

  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.

• Transformation of tobacco plants with virEl gene derived from Agrobacterium tumefaciens pTiA6 and its effect on crown gall tumor formation

  53-56.

  E. Szegedi

  A. Oberschall

  S. Bottka

  R. Oláh

  D. Tinland

  Views:

  286

  The VirEl protein plays a key role in the transport of VirE2 protein from the bacterium to the plant cell during crown gall tumor induction by Agrobacterium. The virEl gene of A. tutnefaciens pTiA6 was cloned into the plant transformation vector pTd33 yielding pTd93virEl that was introduced into A. tuniefaciens EHA101 and used for tobacco transformation. The presence of the foreign DNA in the putative transgenic plants was confirmed by PCR analysis. Nine of the 41 transformed plants formed only small tumors following infection with the wild-type A. vitis octopine strain AB3. This property was inherited into the T1 generation. The expression of virEl gene in TI plants was demonstrated by Northern blot analysis.

   

• Model experiments for establishment of in vitro culture by micrografting in apple

  47-49.

  J. Dobránszky

  E. Jámbor-Benczúr

  I. Hudák

  K. Magyar-Tábori

  Views:

  470

  Micrografting was used in our experiments for establishment of in vitro culture from one rootstock (`JTE-F') and three scion cultivars (`Remo', 'Rewena' and `Reanda') of apple. Shoot tips of these cultivars were harvested from field and grafted onto in vitro rootstock cultivars. Their survival and development were studied. 42-93% of shoot tips survived and developed further depending on cultivar. Impermanent browning of sticking agar-agar could be observed in 21-25% of the micrografts depending on cultivars but discolouration of agar-agar ceased within one week and did not cause any death of shoot tips. We used micrografting successfully for establishment of in vitro culture from cultivars, from which earlier with conventional methods the culture establishment was not possible because of hard tissue browning. However, further studies are necessary to ensure the survival and development of shoots after removing them from micrografts.

• Mutation induction in sweet basil (Ocimum basilicum L.) by fast neutron irradiation

  30-38.

  E. Enkhbileg

  A. Fenyvesi

  B. Bíró

  M. G. Fári

  E. Kurucz

  Views:

  703

  Basil species are highly sensitive to exterior environmental conditions and its consequences lead to great economic and agronomic losses. In this research, a mutation method was optimized out for creating a new variety of Ocimum basilicum L., which could tolerate the extreme/extraordinary climatic circumstances or biotic stresses, such as fungal diseases. Fast neutron irradiation was performed on the Hungarian commercial variety seeds with doses of 5 to 60 Gray and grown into fully developed plants. Numerous phenotypical changes like deformed congestion, leaf mutation, and low growth occurred, especially at higher dosages. Then to confirm whether the plantlets had mutation or not, and to detect the molecular variation and relationship, fingerprinting profiles of the developed mutant regenerants and donor plant have been assessed using ISSR markers. 115 loci were yielded, ranging from 0.2 to 1.5 kb, out of which 110 loci were polymorphic in nature, representing 95.6% polymorphism. The most suitable primer to determine the genetic diversity within the Ocimum species was the UBC-856 with 0.42 PIC and 4.1 MI values.

• The effect of storage to optical properties in case of two apple fruit varieties

  33-36.

  A. M. El Shal

  P. Riczu

  A. Nagy

  E. Sulyok

  Z. Szabó

  J. Nyéki

  Views:

  909

  The keeping quality of fruits is a very important factor in storage point of view, since it could be elongated the consumption time of fruits. In many cases the storage may be necessary, e.g. in short time it is not able to market due to the rich harvest, or all fruits could sell in markets throughout the year. The keeping quality of various fruit species is greatly different; moreover it could be observed some differences between the varieties as well. In our research, we have investigated the spectral properties of the external surface and fl esh of two ripe apple varieties – Jonagored and Granny Smith – before and after storage (about 3°C and about three weeks). The hyperspectral investigation was carried out with AvaSpec-2048 Fiber Optic Spectrometer. The experimental results represented the differences between healthy and chilling injured apple fruits. Furthermore, some indices were created to given countenance to the spectral differences.

• Two new registered table grape varieties

  51-53.

  E. Hajdu

  É. Ésik

  Views:

  246

  Two table grape varieties — Kósa and Narancsízű — were registered of the hybrids bred in the Research Institute for Viticulture and Enology in I lungary. Both varieties ripe early and are much in demand for the attractive clusters and flavours. As they are hybrids of Vitis vinifera they require similar growing conditions. In the same time with their qualification the two varieties are included in the variety list and allowed to be propagated.

• Phyl-Gold: a product to diminish russeting of 'Golden Delicious' apples

  131-133.

  L. Csiszár

  T. Bubán

  F. Takács

  M. Benedictyné Rátz

  L. Oláh

  Views:

  294

  Producing high quality apples in mature trees of the cv. 'Golden Delicious' is rather difficult because of the russeting of it's fruits, especially in seasons of high relative humidity and/or wetness.

  Earlier experiments proved the possibility to decrease russeting by treatments of GA₄.₇ during a period after petal fall.

  Phyl-Gold, a product of Phylaxia Co. (ai. 10 g1^-1 GA₄.₇) was applied to inhibit russet formation in fruit skin of 'Golden Delicious' apples. Four consecutive sprays were carried out (with 10 ppm a.i.) in weekly intervals, starting at petal fall and tank-mixed with the current pesticides of the plant protection program.

  Due to the GA₄.₇ application the russet formation decreased at a rate of economical importance. As for the side-effects of treatments, fruit set was reduced slightly in trees treated, however, there was no consequent influence on return bloom.

   

• Prevention and protection technologies – How do the growers get ready for climate change?

  67-69.

  D. D. Nagyné

  Z. Szabó

  J. Nyéki

  M. Soltész

  Views:

  3249

  Within the sector of fruit growing, climate change related tasks cover a rather wide range of activities. According to what is claimed by the literature, all decisions impacting the sector should be made conformably with climate change in order to advance an increase in yield security. This, regardless of the impacts of climate change, is also one of the key questions in fruit growing. Regarding protection against extreme weather events, in addition to technological and technical elements, the level of importance assumed by farmers for the abovementioned protection techniques as well as the type and extent they intend to use of this in practice are also worth of studying. This ongoing research beginning in 2009 mainly focuses on studying the opinions of fruit farmers making up the target group for this analysis. The questionnaire survey primarily intends to study their knowledge on the definition of climate change as reactivity to unfavourable weather events occurring in the growing. The study aims at providing a realistic view on the fruit-farmers’ knowledge on climate change and on how technological elements, new technical solutions applicable to mitigate damage are used during production.

• Effects of salinity stress induced by hot spring water on tomato growth, yield and fruit quality under hydroponic cultivation in Japan

  23-28.

  A. Musabyisoni

  M. C. Mutimawurugo

  A. N. Niyokuri

  Views:

  312

  The objective of this research was to test hot spring water as a source of salt to improve tomato quality under the hydroponic system. This research was conducted at Yamagata University, in Japan from February to July 2017. Salt stress was induced using salts of hot spring wastewater collected from Yupoka Onsen (Tsuruoka, Japan). The treatments were EC 2, 4, 8 12, and 16 mS/cm which were arranged in a Randomized Complete Block Design (RCBD) with five replications. Tomato plants were grown at EC 2 until flowering and then subjected to different EC concentrations until harvesting. The data were collected on plant growth parameters and fruit quality. Fruits were harvested at the red stage until the 5^th truss. The results showed that fruits' Soluble Solids Content, organic acid, Nitrate contents and Sugar: Acid ratio increased significantly at EC 16 mS/cm and in the upper trusses compared to EC 2 and in the lower trusses. In contrast, fruit weight significantly decreased at EC 16 mS/cm and in upper trusses. Leaf thickness, size and SPAD, and specific leaf weight significantly declined at EC 16 mS/cm and upper leaves compared to EC 2 and in lower leaves. Plant height started to decline significantly after three weeks of treatment at EC 16 compared to EC 2.

• Pál Maliga, founder of the research in floral biology of fruit species in Hungary

  57-60.

  J. Nyéki

  M. Soltész

  Views:

  810

  Pál Maliga founded the Hungarian research in floral biology of fruit species during his more than forty-year-long carrier. Almost all pome and stone fruit species have been covered by his activities, but he also dealt with the fertility of walnut and chestnut. Regularities have been revealed and the methodical studies opened the way to approach and elaborate alternatives for the association of varieties in planning high yielding commercial plantations. In his breeding activity the choice of crossing parental varieties was based on the knowledge in fertility relations. The obtained sour cherry varieties represent the world-wide maximum quality, reliability and security of yields. Hungarian renewed sour cherry cultivation owes its fame and prosperity to those varieties, nevertheless also to the radical knowledge of the biological bases of fertility.

• Water use of young apple trees related to leaf area development

  61-63.

  T. Lakatos

  T. Bubán

  Views:

  389

  Present paper describes an investigation concerning seasonal water use and foliage area development of apple trees. Sap flow velocity was measured in the trunks of five years old apple trees cv. `Florina'/M.26 by a thermal dissipation (Granier) method from 20th of May to the end of September in 1998. The development of foliage area was estimated by a method including leaf area measurements, recording of leaves and shoot length. The foliage area reached to 70% of the maximum yearly value at beginning of June. The remaining 30% developed to the end of August. The leaf area specific water use was considerable higher in June and July, than in second part of summer. The trends of ET-FAO and water use curves differed mostly in the late season: the ET-FAO curve falls quite in September compared to August, whereas the value of water use was a similar as in August. This insensitivity of ET-FAO in this period may be a great disadvantage while using the Penman-Monteith equation in irrigation scheduling of apple.

• Some microbial treatments against the tomato leaf miner; Tuta absoluta (Merick) under natural field conditions

  81-84.

  Mohammed Amira S.

  El-Khatteeb Nagwa M. M.

  A. Ezzat

  Views:

  346

  In an attempt to find more effective methods and safety to control the tomato leaf miner, Tuta absoluta, this research was conducted to study the efficacy of the four bio-treatments ; two bacterial isolates (Bacillus subtilis. and Pseudomonas Fluorescence), one fungal isolate Trichoderma viride) and Spinosad as a microbial insecticide compared with the most common insecticides used against the dipterous and lepidopterous leaf miners in Egypt; Profenofos and Aphox. In the two successive seasons; 2011 and 2012, the fungal isolate Trichoderma viride achieved the lowest infestation(numbers of infested leaflets, mines, infestation percentages) which were 167, 195, and 21.9% resp.in season 2011 and 198, 222 and 26.2% resp. in season 2012. While the highest infestation was occurred in case of using the insecticides, Aphox (423, 559 and 55.9% resp.& 384, 839 and 72.2%. and Prohpenofos (436, 562 and 57.7% &391, 534 and 51.7% resp.).during 2011 and 2012 respectively. The other treatments occupied the intermediate levels. On the other hand, the yield of tomato fruits was increased by 75% over the check in case of plants treated with Trichoderma viride isolate, but the pesticide treatment given weak or no impact in increasing tomato crop. In season 2012, the infested tomato fruits percentages with T. absoluta larvae and Rhizoctonia soil rot disease(that Frequently observed incidentally) were recorded the minimum levels obtained by spraying Trichoderma viride isolate(21.38 and 10.32% resp.). In contrast, the maximum levels were recorded in Prophenofos (44.87 and22.78% resp.) and Aphox treatments(47.22 and 27.78% resp.).

• The effect of Regalis® (prohexadione calcium) on the reduction of fire blight (Erwinia amylovora) severity in apple trees

  61-66.

  P. Sobiczewski

  T. Bubán

  Views:

  366

  Due to the lack of effective and non-phytotoxic materials for control of the blossom and shoot blight phase of fire blight in pome fruit trees, two novel control strategies have emerged: shoot growth retardation by bioregulators and applying resistance inducer compounds. Prohexadione calcium (ProCa) is the active ingredient of the bioregulator Regalis^® registered in several European countries. The reduction of shoot growth elongation is the most obvious effect of ProCa. Furthermore, it causes significant changes in the spectrum of flavonoids and their phenolic precursors, leading to the considerable reduction of susceptibility to fire blight.

  In Poland, potted one-year-old apple trees of cvs. Gala Must grafted on M.26 and Sampion on M.9 (in 2001) as well as Gala Must on P.60 (in 2002) were treated with Regalis® at a range of concentration of 250, 150 or 150 + 100 ppm, respectively. The inoculation of shoots was made with the strain No.691 of E. amylovora (10⁷ cfu/ml), on the 7th and 21st'day after treatments with Regalis. In Hungary, during the years of 2002 and 2003 one-year-old container grown apple trees of the cvs. Idared/M.9 and Freedom/M.9 were treated with the prohexadione-Ca, the active ingredient of Regalis® 100, 150 or 200 ppm, two weeks before inoculation with the Ea 1 strain of E. amylovora (10⁷ cfu/m1).

  In Poland, the suppression of fire blight in shoots reached up to 80%, depending on concentration and application time of Regalis®. In Hungary, the effect of prohexadione-Ca treatments, determined by the length of necrotic lesion developed, proved to be better than that of streptomycin used for comparison.

• How to produce large sized microtubers of potato cv. Desiree

  33-36.

  K. Magyar-Tábori

  J. Dobránszky

  Views:

  340

  In vitro tuberization was induced on explants with different number of nodes layered on a medium with high sucrose (8%) content: 30, 15, 10, 7 and 6 explants per jar were cultured containing 1, 2, 3, 4 or 5 nodes, respectively. Microtubers developed were graded by their smallest diameter, and the number of tubers per jar, their size distribution, their fresh weight and the multiplication rate were recorded. The highest multiplication rate (1.98) was obtained for explants with 5 nodes. The size distribution of tubers was markedly affected by treatments. The majority of microtubers (49.4%) were 6-8 mm in the case of the smallest explants (with I node). When explants with 2 to 5 nodes were used, the most microtubers were 8-10 mm but with an increase of explant size, more and more microtubers were produced with larger diameter up to 16 mm and average fresh weight of tubers also increased with the increase of explant size. For the microtuber production of Desiree the use of explants with two nodes can be suggested because in this treatment the average fresh weight of microtubers was high enough (250 mg) and the number of large sized microtubers was very high (79% was larger than 6 mm and 53% was larger than 8 mm).