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  • Author or Editor: F. Tóth x
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The damage caused by root-knot nematodes (Meloidogynidae) (irregular galls of different sizes on the plant roots) is a general problem in greenhouses in Hungary.The effect of Trifender microbiological preparation has been investigated on the degree of damage caused by root-knot nematodes in green-house pepper. We set up our experiment in Pusztamonostor (Jászság region, Hungary) in a family farm in 2008 and 2009. We carried out preliminary evaluation (Zeck-scale; 0–10) in the precrop with symptomatic assessment. According to the preliminary evaluation, the infection showed rates of 2–3 on the average.The results of 2008 show that Trifender had no effect on the number of females, but the plant height has been increased by 12 and 15%, and yield has grown by 25–35%. But on the contrary, in 2009 the number of females was decreased by 33%, and plant height was increased by 11%.

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The characteristics of crystallization, melting and spherulitic growth of a random propylene copolymer (PRC) containing small amount of ethylene were studied in the presence of a selective Β-nucleating agent (calcium pimelate). It was established that the products of isothermal and non-isothermal crystallization are very rich in Β-modification but have mixed polymorphic composition. The formation of α-modification may be attributed to Βα-transition on the surface of growing Β-spherulites resulting in αΒ-twin-spherulites. During melting of PRC of Β-modification, the characteristics observed with Β-nucleated propylene homopolymers, namely, a Βα-recrystallization of recooled samples and separated melting of non-recooled samples (i.e. the melting memory effect), as well as a ΒΒ-recrystallization leading to a perfection of the structure within the Β-modification, are also demonstrated. The disturbance of regularity of the polymer chain highly reduces the tendency to Β-crystallization. In contrast to the observations with propylene homopolymers, the growth rate of α-modification (G α) is higher than that of Β-modification (G β) and no critical crossover temperature can be found (T(Βα)=413 K) below whichG α>G β. The experimental results show that a partial disturbance of chain regularity by incorporation of comonomer units considerably reduces the tendency to Β-crystallization.

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Abstract

Microvascular function has been assessed by determining the rhythmic oscillations in blood flow induced by the vasomotion of resistance vessels. Although laser-Doppler flowmetry (LDF) allows simple, non-invasive evaluation of this flow-motion in the cutaneous microcirculation, the temporal and spatial reproducibility of such assessments remains unclear.

In the present study, we investigated cutaneous flow-motion in three consecutive years in eight skin regions using LDF in six healthy young volunteers. The characteristic flow-motion frequency was determined using fast-Fourier transformation. Additionally, in two years a more traditional measure of microvascular reactivity, postocclusive reactive hyperemia (PORH) was evoked in the forearm after transient brachial artery occlusion (1–2–3 min) induced by cuff inflation.

Well-defined flow-motion was found in six regions showing significant differences in frequency: the highest flow-motion frequency was found in the frontal and temporal regions (8.0 ± 1.1 and 8.5 ± 1.0 cycles/min, cpm, respectively, mean ± SD) followed by the scapular, infraclavicular and coxal regions (7.5 ± 1.3; 6.7 ± 1.1 and 6.5 ± 1.2 cpm, respectively). The lowest, stable flow-motion was found in the posterior femoral region (5.5 ± 1.0 cpm), whereas flow-motion was detectable only sporadically in the limbs. The region-dependent flow-motion frequencies were very stable within individuals either between the body sides, or among the three measurements, only the infraclavicular region showed a small difference (114 ± 17%∗, % of value in 1st year; ∗P < 0.05). However, PORH indices differed after 2–3 min occlusions significantly in consecutive years.

We report that flow-motion frequencies determined from LDF signals show both region-specificity and excellent intra-individual temporal and spatial reproducibility suggesting their usefulness for non-invasive follow-up of microvascular reactivity.

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Theridion impressum is one of the dominant foliage dwelling spider species of maize fields in Hungary. Spider webs were collected from Bt and isogenic maize plots in three successive years. Captured insects in the web were identified. The most frequent prey items were aphids, plant hoppers and beetles. Although the number of captured insects in web samples from isogenic maize was slightly higher than those from Bt maize in the case of almost each insect order, except for two samples (Sternorrhyncha, 2001; Neuroptera, 2002), the differences between Bt and isogenic samples were not significant.

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We investigated alfalfa and stinging nettle from the point of view of their potential to supply natural enemies of pests for protecting greenhouse cultures. We carried out a three year long study based on sweepnetting. The most frequent predatory insect was Orius niger (Wolff) in alfalfa and nettle. This species among others has an important potential in the biological control of thrips. Among ladybugs, the most important species in alfalfa and nettle were Propylea quatuordecimpunctata (Linnaeus), Coccinella septempunctata Linnaeus and Hippodamia variegata (Goeze), which consume significant amounts of aphids. The most frequent spider family in alfalfa and nettle was Thomisidae and Philodromidae. The dynamics of their prey composition suggests that these taxa present a significant suppressive force on pests. The predator thrips Aeolothrips intermedius Bagnall that feeds on phytophagous thrips, mites and other soft-bodied arthropods was also significant in the arthropod assemblage of alfalfa. Our three-year investigation showed that the abundance and the species richness of the natural enemies of greenhouse crops are suitably high in both alfalfa and nettle stands. The number of generalist predators, natural enemies of pests, the most versatile tools of pest management reached its peak between mid-May to late June in nettle whereas due to mowing, the highest values for alfalfa were recorded from June to mid-August.

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Deterministic seismic hazard computations were performed along four different profiles across the downtown of Budapest. Synthetic seismograms were computed by the so called “hybrid technique”. By applying the hybrid technique it is possible to take into account the focal source, the path and the site effect together. Four independent computations have been performed using the same seismic source but different profiles. The parameters of the seismic source were adopted from the parameters of the well-known 1956 Dunaharaszti earthquake. The focal mechanism and the homogeneous and heterogeneous parts of the profiles are known from geophysical and geological data of the investigated area.As the results of the computations PGA (peak ground acceleration) grid maps of the downtown of Budapest for the three different components came into existence. Furthermore spectral acceleration (response spectra, SA) and RSR charts of the synthetic seismograms for the four different profiles were created. The PGA grid maps show that the maximal PGA values are situated at the eastern (Pest) part of the downtown, and their values are 50–200 cm/s 2 .For the downtown of Budapest a special seismic risk map have been prepared. This special seismic risk map were created on the basis of the difference between the maximal amplitude frequencies of SA of synthetic seismograms and the building’s eigenfrequencies at every 0.1 km 2 of the downtown. In order to determine the building’s eigenfrequencies microseismic noise measurement were performed at 6 different buildings in the downtown. The special seismic risk map shows that the buildings situated at the hilly western section of the downtown have higher seismic risk than the ones at the flat eastern part.

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Recent years of studies have suggested that the common crab spider (Xysticus kochi) has a great potential against the western flower thrips (Frankliniella occidentalis) . The efficiency of applying a single predator against a pest however, is made uncertain by many different factors. Using a mixture of predators on the other hand, can overcome the difficulties of using a single-species agent, since different predators have different environmental demands and preying habits. Our experiments involved releasing a non-selected assemblage of arthropods, collected by sweep-net in alfalfa and stinging nettle, into greenhouse pepper stands. Interestingly, while there were twice as much thrips in the experimental greenhouses than in the control (mainly conventional) ones, crop yields were similar. The ratio of predators-preys in experimental greenhouses was not different from that in the control greenhouses, too. Probably the release of predators and lack of chemical treatments in experimental stands resulted in a 43% increase in the amount of Orius species. In search of a cost-effective, environment-friendly pest management method, the application of a mass-collected, non-selected assemblages of arthropods has a definite potential. Further investigations are needed to increase the efficiency and to monitor the potential drawbacks of this method.

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The sectorial material transport disorders induced by cutting back were first detected some two decades ago (Brunner, 1976; 1990; Brunner et al., 1996). The pruning of oblique scaffold branches to an upper bud causes one-sided drying up and material transport disorders on the lower side of the branch, leading to the formation of close to horizontal shoots on the lower side of the scaffold branch without any tendency for the branch to become bare, and with a considerable reduction in manual labour requirements. This is the essence of this novel pruning method having a bending effect.

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The physiologically-based pruning methods elaborated by the authors were found to increase intensity in various ways, including early fruiting, improved yield and quality, and a reduction in the height of the cropping area, allowing at least 80% of the fruit to be picked from the ground. Compared with the Lespinasse control, crowns with a valve-like central leader on a sectorial spindle gave a surplus yield of 8.5 t/ha/year over the average of 3 years, including an increase of 2.3 t/ha/year in the yield of extra quality and grade I fruit.

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The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a new pest of corn in Europe. Future management may include the use of natural enemies. Our study focused on the deter­mi­na­tion of density and species composition of spiders in corn fields, as well as in the adjacent corn field margins, during the peak flight period of WCR adults. An additional objective was to test different sampling methods, used for spider collecting, in corn fields and in adjacent corn field margins. The field study was conducted in July and August, 1999, in experimental corn plots, as well as in the adjacent field margins, owned by the Cereal Research Institute, Szeged, in Southern Hungary. Spiders were collected by individual plant search and by sweep nets. Number of spiders /m2 was significantly higher, whereas /m3 was significantly lower in the corn plots compared to the adjacent field margins. Remnants of WCR adults were found in theridiid [Theridion impressum L. Koch, T. pictum (Walckenaer), Enoplognatha latimana Hippa and Oksala] and agelenid (Agelena sp.) webs. We observed that individuals of both families were able to kill 1-5 adult beetles within 90 minutes.

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