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The effect of different fat content fish feed on the production parameters and meat quality of the hybrid striped bass
33-37Views:443The interspecific ’hybrid striped bass’ is the result of cross breeding. Their offspring have got good chances of growth and tolerate extreme water temperatures and the content of dissolute oxygen more than their parents. Furthermore, they are more resistant to diseases. Therefore, the hybrid is perfectly suitable for intensive fishery production.
Our experiment lasted for seven weeks. We analysed the indices of growth and production of the hybrid as the consequence of nurturing them with two feeds of high nutritive value during this period. We examined the content of fat and of fatty acids in the flesh of these fish. There were no considerable differences in terms of weight gain, feed conversion ratio and uneven growth between the two groups, while survival was less likely among the the fish which had consumed more fat. We demonstrated, examining the flesh of the individuals which had consumed feed containing lower fat content, that it was fattier and contained more dry matter than those that had been fed of higher fat content. Besides, the content of omega-3 and omega-6 fatty acids was higher in the fish that had consumed less lipids.
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Calculating possibility of the leaf area index of apple and pear trees
229-233Views:450A significant proportion of the aboveground green and dry weight of the plant constitutes the foliage. The canopy is an important factor of plant growth. On one hand the canopy absorbs the solar energy, which is necessary for the photosynthesis, on the other hand accumulates the absorbed nutrients by the roots, and the most of the water-loss happens through the foliages. The determination of the full canopy is not an easy target. In our research we developed a measurement method to determine the leaf area. With the parameters of the examined tree (leaf length and maximum width) and the data of ADC AM 100 leaf area scanner we determined the k-value, with which we can easily and fast evaluate the leaf surface.
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The effect of feeding different glycerol sources on the performance of lactating sows
99-103Views:248Glycerol is a by-product of the biodiesel industry and it might be a good alternative to moderate the energy deficiency of sows during the lactation period. Preliminary experiments were carried out to test the effect of a powder, solid based “food grade” glycerol source with 72.9% glycerol content (Trial 1) and a liquid “feed grade” glycerol source with 86% glycerol content (Trial 2) on the performance of lactating sows and their litters. Trial 1 was conducted with 5 Hungarian Large White×Hungarian Landrace sows/treatment (313±24.9 kg) and Trial 2 with 12–12 DanAvl (323±17.0 kg) sows and their litters/treatment. Neither the solid, powder based glycerol (Trial 1), nor the liquid glycerol source (Trial 2) had significant effect on the feed intake, reduction in live weight and back-fat thickness, and weaning-tooestrus interval (p>0.05) of lactating sows. In Trial 2, on the 14th, 21st and 27th days of lactation the milk samples were collected and it was found that 50 kg/t glycerol decreased the protein content of milk samples (p<0.05). Glycerol supplementation had no effect on dry matter, fat, lactose content of milk samples (p>0.05). In Trial 2, no significant difference was found between control and experimental sow groups in triglyceride concentration of blood samples and in the activity of liver enzymes (ALT, AST, GGT; p>0.05), but the concentration of plasma glucose and cholesterol increased tendentiously (p<0.10).
Based on our preliminary results, it can be concluded that additional dose trials are needed to perform in order to study the effect of glycerol supplement on milk production and on metabolic processes of lactating sows.
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Gene resources for improvement of drought tolerance and yield quality in dry pea breeding
105-111Views:203The effectiveness of selection for improved drought tolerance and consumption quality in the progeny of crosses between pea cultivars with semi-leafless (afila) and normal leaves and different origins, respectively, were investigated. After single crosses, parent cultivars and F1, F2 and F3 generations were grown under non-irrigated conditions in the same trials. We created a colour scale from 1 to 9 to measure statistically the shade of seed colour. The tolerance of genotypes against high temperature was measured by the number of pods per plant. The 3:1 segregation
observed in the F2 generation of crosses between semi-leafless and conventional cultivars indicated that the semi-leafless character is determined by a recessive gene. In contrast, the ratios of conventional (Af) and semi-leafless (af) genotypes were 7:1 and 9:1 ratio in the progenies of crosses of Af × af. The genetic progress was effective for improving the seed quality in F3 generation from crosses Af x af where we found that multiple
dominant alleles controlled the orange colour of cotyledons and its high heritability (h2 A=0,63). Selection is more effective in producing the genotypes with high yield and normal leaves if the crosses were made between the western European cultivars such as semi-leafless Profi and Delta used as maternal cultivars and conventional Auralia cultivars. In this case, there were decreases in the consumption quality, such as seed size and shade of colour. The selection based on the seed weight of single plants for increasing drought tolerance seemed to be more effective in F4
strains with normal leaves originated from Czechoslovakian maternal cultivar Y228; however, the genetic progress in the improvement of seed size and colour quality was slow. -
The effect of wet compost extract on the root tubers of green pea
51-54Views:265Nitrogen plays significant role in the life of plants, it could be the main limiting factor of plant growth. Sustainable plant nutrition pays attention to satisfy the plants’ nutrient demand without chemical fertilizers, e.g. by bounding the atmospheric nitrogen. The nitrogen fixing organizations play important role in supplying plants with nitrogenbecause the N2-fixingbacteria can fix high amounts of nitrogen.
Many effects of the sewage sludge compost extracts is known in the literature. We studied the effect of sewage sludge compost water extract in laboratory conditions on the growth of Rhizobium spp. isolated from green pea, while in a small plot experiment thepea-Rhizobium symbiosis were studied on sandy soil in the Nyírség region. The extract was produced under aerobic conditions. The compost extract was applied before and/or after sowing. In the laboratory experiments we used the sterile version of extract, in different doses.
In our work we present the effect of compost water extract on the number of green pea roots nodules, dry weight of the plant and reproduction of the Rhizobium bacteria. -
Correlations of the growth indexes and yield of winter wheat in a long-term experiment
139-144Views:220The experiments were carried out at the Látókép experimental station of the Centre for Agricultural Sciences of University of Debrecen on chernozem soil in a long term winter wheat experiment. As forecrop rotation, we set up two models: a biculture (wheat and corn) and a triculture (pea, wheat and corn). We applied three levels of nutrients during the fertilization process (control, N50P35K40 and N150P105K120). The third variable studied was irrigation in case of which we tested non-irrigated variables (Ö1) and irrigation variables complemented up to the optimum (Ö3).
The effect of pre-crops, irrigation and nutrient-supply levels on some growth-parameters (LAI, LAD), weight of dry matter, just as SPADvalues and yield amounts of winter wheat has been investigated in this experiment. We tried to find out the extent of relationship between the different parameters, and we used the correlation analysis. The correlation analyses have confirmed that all of the investigated parameters had almost in all cases close positive correlation to the yield amount. These results have confirmed that the leaf area, the leaf duration, the SPADvalues, the fertilization and the forecrop have altogether resulted in the production of maximum grain yields.
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Preliminary results of the combined production of duckweed Spirodela polyrhiza and common carp (Cyprinus carpio) in an aquaponic system
83-89Views:344As a result of population growth, increasin amount of food is needed, and agriculture is under an increasing burden to meet these needs. Traditional agriculture is often attacked due to its environmental impact. We must find alternative, environmentally friendly ways to produce more food. Aquaponics is a closed system in which we can produce both fish and plants at the same time. Duckweed species are small, aquatic, floating plants belonging to angiosperms. It can potentially be an alternative protein source, due to its high protein content, good amino acid supply, and rapid growth. Under suitable conditions, it doubles its weight in 2–4 days, and can reach a yield of 30 t ha-1 year-1in dry matter. It forms a carpet on top of the water and can be found in slow-moving or still waters. Since they are resistant to a wide range of nutrient concentrations, they are also suitable for cleaning wastewater (such as eutrophicated lakes, sewage reservoirs, liquid manure storage). Fish feed is the primary nutrient source for aquaponic systems, which usually contains fishmeal. If duckweed can be used as an alternative for fishmeal in the feed, it could improve the sustainability of the aquaponic and aquaculture systems. In this study, the aim was to develop an optimal harvesting protocol for duckweed Spirodela polyrhiza under aquaponic conditions. In a four weeks experiments, four harvesting protocols were set up, a control where only biomass measurements were made, a 25% group where 25% of the biomass at the time of measurement was harvested, and a 50% and a 75% group where at the time of measurement 50% and 75% of the biomass was harvested. Three replicates were used per treatment. We weighed the biomass every week and removed the amount corresponding to the group. Based on the preliminary results, it can be said that more biomass was obtained in the groups with the 25% harvesting protocol and the control group.
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Microbiological preparations affecting the soil nutrient availability and growth of ryegrass in a pot experiment
49-53Views:227The effects of different bacterial fertilizers and their combinations with NPK fertilizer and wheat straw were investigated on some soil properties (chemical parameters) and on the biomass production of testplant. The applied quantities of the bacterial fertilizers were the double of the recommended dose. The experiment was set up in 2013 at the Institute of Agricultural Chemistry and Soil Science, in a three replications, in a random block design. Calcareous chernozem soil; originating from Debrecen (Látókép) was used with ryegrass (Lolium perenne L.) test plant. At the end of the experiment (after 8 week) the samples of soil and plants were determined for nitrate-nitrogen, ALsoluble phosphorus and potassium content of soil, the weight of green biomass of ryegrass per pot, the dry matter and moisture content of ryegrass. Straw treatment resulted better water and available nutrient content of soil in general. Inoculation however was not improving the biomass production over the fertilizer treatment. Interrelation with the recommended dose could be further studied.
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Assessing the impact of salinity stress on some morpho-physiological traits of two chickpea genotypes under hydroponic conditions
47-53Views:202Evaluating the performance of crop species to salinity stress is considered an intricate task due to differences in performance, response and susceptibility at different phenological stages of chickpea crop. Assessment of the performance of chickpea genotypes in response to NaCl-induced salinity stress at the initial vegetative phase is of great importance to have a crystal idea about the threshold level of tolerance. An experiment was carried out under hydroponic conditions to evaluate the performance of two chickpea genotypes (ELMO and ORION), in response to different salinity levels (0, 25, 50 and 75 mM NaCl) as factorial arrangement under completely randomized design with three replications. The average of shoot and root dry matter weight was significantly higher for the ELMO genotype at the control treatment (1.143, 0.4133 g respectively), while it was significantly lower in the two genotypes ORION and ELMO at the highest salinity level (0.267 and 0.2700; 0.0433 and 0.0533 g respectively). The root to shoot ratio was significantly higher in both genotypes in the control and the lowest salt level (25 mM NaCl), without significant differences among them (47.98, 43.30, 37.10 and 36.25% respectively). The relative water content and stomatal conductance were significantly higher in the ORION genotype (88.01%; 335.40 mmol m-2 s-1) compared to ELMO (84.09%; 299.10 mmol m-2 s-1), and increasing salinity level caused a proportional decline in both traits, where they were significantly lower at the highest salt level (75Mm) (77.45%; 87.50 mmol m-2 s-1). Results indicate genotypic variability in response to NaCl-induced salinity stress under hydroponic conditions and the physiological traits are more expressive and reliable as selection criteria than morphological ones.