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The effect of the queen's age on the Varroa mite (Varroa destructor) burden of honey bee (Apis mellifera L.) colonies
Published December 28, 2018

An apiary trial was conducted in 2016 August to October in Szabolcs-Szatmár-Bereg County, Nyírmada to evaluate the influence of queen’s age on the Varroa destructor-burden in the treatment colonies. Sixty colonies of bees belonging to the subspecies Apis mellifera carnica pannonica in Hunor loading hives (with 10 frames in the brood chamber.../deep super) were used. The colonies were treated with amitraz and the organophosphate pesticide coumaphos active ingredients. The amitraz treatment includes 6 weeks. The coumaphos treatment with Destructor 3.2% can be used for both diagnosis and treatment of Varroasis. For diagnosis, one treatment is sufficient. For control, two treatments at an interval of seven days are required. The colonies were grouped by the age of the queen: 20 colonies with one-year-old, 20 colonies with two-year-old and 20 colonies with three-year-old queen. The mite mortality of different groups was compared. The number of fallen mites was counted at the white bottom boards. The examination of spring growth of honey bee colonies has become necessary due to the judgement of efficiency of closing treatment. The data was recorded seven times between 16th March 2017 and 19th May 2017.

Data on fallen mites were subjected to one-way analysis of variance (ANOVA) and Post-Hoc Tukey-test. Statistical analysis was performed using the software of IBM SPSS (version 21.). During the first two weeks after treatments, the number of fallen mites was significantly higher in the older queen’s colonies (Year 2014). The total mite mortality after amitraz treatment in the younger queen’s colonies was lower (P<0.05) compared to the three-year-old queen’s colonies. According to Takács and Oláh (2016) although the mitemortality tendency, after the coumaphos (closing) treatment in colonies which have Year 2014 queen showed the highest rate, considering the mite-burden the colonies belongs to the average infected category. The colonial maintenance ability of three-year-old queen cannot be judged based on the influencing effect on the mite-burden. The importance of the replacement of the queen was judged by the combined effect of several factors.

During the spring-growth study (16th March–19th May) was experienced in the three-year-old queen’s colonies the number of brood frames significantly lower compared to the one- and two-year-old queen’s colonies. In the study of 17th April and 19th May each of the three queen-year-groups were varied. Therefore in the beekeeping season at different times were determined the colonial maintenance ability of queens by more factors: efficiency of closing treatment in early spring, the spring-growth of bee colonies, the time of population shift (in current study, this time was identical in each queen-year), honey production (from black locust).

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Examination of drought stress of two genotype maize hybrids with different fertilization
Published May 20, 2020

In the growing season of 2019, we analysed stress resulting from climatic factors on maize hybrids of different genotypes, with the aim of gaining a better understanding of the physiological responses of each hybrid, which might support the elaboration of a cost-effective irrigation plan.

Our experiments were carried out at... the Látókép Experimental Station of the University of Debrecen on calcareous chernozem soil in a small-plot long-term field trial with strip plot design. In the scope of the experiment, N-fertilizer doses were applied as basic fertilizer and top-dressing in addition to the non-fertilized (control) treatment. The 60 and 120 kg N/ha doses applied as basic fertilizers in the spring were followed by top-dressing in the V6 phenophase with a +30 kg N/ha dose. Measurements were carried out with the involvement of the Renfor early (FAO 320) and Fornad (FAO 420) late maturity hybrids-

The stomata of the plants became more and more closed with the progression of the phenological phases; their stomatal conductance decreased. However, the hybrids responded differently to environmental stress. In the case of the Renfor hybrid, the highest conductance (669 mmol/m2-s) was recorded in the V12 phenophase with the 150 kg N/ha treatment. The stomata were more open due to the high turgor pressure, allowing plants to evaporate properly. The plant was in its worst physiological condition on 2nd July, at the time of the appearance of the last leaf in the case of the 120 kg N dose (224 mmol/m2-s). The value measured in the V12 phenophase has already shown that the stomata were closing due to the self-regulating system of the plant. It would have been necessary to dispense irrigation water following the measurement. This confirms the finding that water stress can be prevented by measuring stomatal conductance.

In the case of the Fornad hybrid, stomatal conductance was the highest on 12th June (630 mmol/m2-s) in the 90 kg N/ha treatment and it was the lowest (183 mmol/m2-s) in VT (emergence of the last leaf) phenophase in the 60 kg N/ha treatment. In this case, the appropriate time for applying irrigation water would have been early July, when the conditions for the plants were still adequate. Subsequently, the stomata began to close due to a reduction of the water resources available to them.

There was a significant correlation between soil moisture and stomatal conductance, as well as between temperature and stomatal conductance.

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Spent mushroom compost (SMC) – retrieved added value product closing loop in agricultural production
Published September 5, 2018

Worldwide edible mushroom production on agro-industrial residues comprises of more than 11 million tons of fresh mushrooms per year. For 1 kg of mushrooms there is 5 kg of spent mushroom compost (SMC). This enormous amount of waste results in disposal problems. However, SMC is a waste product of the mushroom industry, which contains mycelium an...d high levels of remnant nutrients such as organic substances (N, P, K). The spent mushroom compost is usually intended for utilization, but there are increasing numbers of experiments focusing on its reuse in agricultural and horticultural production. Recently, the increase of the global environmental consciousness and stringent legislation have focused research towards the application of sustainable and circular processes. Innovative and environmentally friendly systems of utilisation of waste streams have increased interest of the scientific community. Circular economy implies that agricultural waste will be the source for retrieving high value-added compounds. The goal of the present work was to carry out a bibliographic review of the different scenarios, regarding the exploitation of this low cost feedstock with huge potential for valorisation.

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System of relations between competitiveness and social cohesion in the European Union (2007–2020)
Published May 16, 2017

I my current essay I tried to prove that the European Union modified its economic policy due to the financial and economic crisis and the fierce global competitiveness requirements. The main emphasis was laid on the increase of competitiveness. Competitiveness became preferred
to cohesion and the economic and social closing up of the newly j...oined Middle-Eastern European countries. The funds for competitiveness for growth and employment increase by 6–7% yearly during the financial perspective between 2007–2013. On the contrary the funds for agriculture and rural development decrease by 3% yearly in this period. The tendency remains unchanged during the financial perspective 2014–2020.
This tendency strengthens the establishment of the two speed Europe concept and causes tensions between the core regions and the peripheries.

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