Show Advanced search options Hide Advanced search options
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.

Show full abstract
New challenges in soil management
Published September 5, 2018
Soil management represents two important tasks that are harmonization of the soil protection with demands of the crop to be grown on the given land under prevailing farming condition. Further goals are to preserve and/or develop the soil physical, biological and chemical condition and to avoid the unfavourable changes of the soil biological a...ctivity and the soil structure. Classical authors emphasised the importance of creating proper seedbed for plants. In the physical approach, tillage was believed to play an important role in controlling soil processes. Consequently, the period of several centuries dominated by this approach is referred to as the era of crop-oriented tillage (Birkás et al., 2017). The overestimation of the importance of crop requirements resulted in damaging the soils, which inevitably led to turn to the soil-focused tillage. Since the first years of climate change, as the new trends have raised concern, tillage must be turned into a climate-focused effort with the aim of reducing climate-induced stresses through improving soil quality.
The development of soil management has always been determined by the economical background. At the same time, deteriorating site conditions have contributed to the conception of new tillage trends by forcing producers to find new solutions (e.g. dry farming theory in the past or adaptable tillage theory nowadays). Győrffy (2009) recited the most important keywords were listed in 2001 and that seemed to be important in the future of crop production. These keywords (endeavours) were as follows:
− Biofarming, organic farming, alternative farming, biodynamic farming, low input sustainable agriculture;
− Mid-tech farming, sustainable agriculture, soil conservation farming, no till farming, environmentally sound, environmentally friendly, diversity farming;
− Crop production system, integrated pest management, integrated farming, high-tech farming;
− Site specific production, site-specific technology, spatial variable technology, satellite farming;
− Precision farming.
Győrffy’s prognosis proved to be realistic and the efforts mentioned above have mostly been implemented. New challenges have also appeared in soil management in relation to the last decades. The most important endeavours for the future are:
1) Preserving climate-induced stresses endangering soils.
2) Turn to use climate mitigation soil tillage and crop production systems.
3) Applying soil management methods are adaptable to the different soil moisture content (over dried or wet may be quite common).
4) Use effectual water conservation tillage.
5) Use soil condition specific tillage depth and method.
6) Adapting the water and soil conservation methods in irrigation.
7) Preserving and improving soil organic matter content by tillage and crop production systems.
8) Considering that stubble residues are matter for soil protection, humus source and earthworm’ feed.
9) Site-specific adoption of green manure and cover crops.
10) Applying site-adopted (precision) fertilization and crop protection. Considering the development in agriculture, new endeavours will occur before long.
Show full abstract
Examination of Reproductive Performance of Roe Deer (Capreolus capreolus) in Hungary
Published December 14, 2004

The objective of the research partly is to compare the reproduction performance of the populations living in different regions with regard to some special characteristics (age, condition).
When estimating the age through tooth wear and cementum-layer-counting there was a difference of 0.87 years in favour of the first one (r=0,840; p<0,00...1). I found cementum layers at 42% of the does in the study after examining the MI teeth.
There was lose connection between the weight (eviscerated, with head and legs) and the KFI (r=0,296; p<0,01), and for further analysis, I used only the KFI as the index for condition.
The regional average KFI varied from 0.24-0.37 in fawns, 0.82-1.73 in does, with individual extremes of 0-4.05. Within the examined regions the highest index belonged to the prime-aged does, while the 1-year-olds had a lower rate, and it was the lowest in the does older than 8 years.
The rate of fertility was between 83,3(ns)-100% as we can see from the presence of the CL. All the examined does were fertile, except in one region, while among the female fawns in two regions I only found three with active ovaries. The average number of CL was 1.5-2.13, and this varied by regions; all in all it was the highest in the 2-7-year-old group (1.96) and in the ones over 8 years (2.00!), while it was lower in the does younger than 1 year (1.90). The high fertility of the does over 8 years is remarkable.
I could examine the number of embryos in two regions during the post-implantation period, and beside 100% fertility I found significant differences among the does, which can be associated with the condition. The ratio of CL carriers and the pregnant does was 100% and 73% in the two regions, the average number of CL were 1.92 and 1.72, while the average embryo number were 1.83 and 1.36 per doe. The difference between the CL and the embryo numbers on the two regions were 5% and 21%. The difference (prenatal loss) is in connection with the age (age class) of the doe. It is possible, however, that in some cases oestrus was not followed by gestation. But in roe deer, owing to the commonly known lack of luteolysis-mechanism (Flint et al., 1994), the regression of the CL of the does that did not get pregnant takes place in December and January, so the CL found in January cannot prove a previous pregnancy, which might have been followed by an abortion.
Although it has to be proven, it seems that the number of the CL (potential progeny) can be associated with the age (r=0,418; p<0,01) and the weight (r=0,312; p<0,01) of the doe, while the embryo number (realised progeny) is influenced by the age of the doe and probably by external factors.
It is essential to continue and extend the research to increase the reliability of the results and their correlation.

Show full abstract
The impact of applying foliar fertilizers on the health condition of maize
Published May 20, 2020


The nutrient supply of plants is becoming more important in plant protection since the appropriate condition of plants can be ensured by optimal and satisfactory nutrient supply to avoid nutritional deficiency diseases. Due to the extreme weather conditions, plants are forced to face several stress factors, which lea...ds to deterioration of the plant health. The increasing occurrence of droughts poses threat to nutrient uptake through the roots since all the nutrients can be accessible to the plants only if they are in dissolved form in the soil – which is not possible in the absence of water. Therefore, the importance of foliar fertilizer is becoming a more and more significant part of the nutrient supply, because with the help of this technology the development of any nutrient deficiency can be prevented.

In this experiment, we focused on the efficiency of two different foliar fertilizers on maize.  Foliar fertilizers were applied two times, once in the stage with 8 leaves and tasseling phenophase of the maize. To verify the efficiency of the foliar fertilizers, the chlorophyll content of untreated and treated plant’s leaves was measured after each application. Moreover, the length and diameter of maize cobs, thousand kernel weight, protein, oil and starch content were also measured, and the results were compared to the untreated (control) ones. According to the results, in all aspects significant differences were observed and due to the laboratory analysis of leaves, in the case of magnesium and zinc supply the foliar fertilizers were able to prevent the development of nutrient deficiency.

Show full abstract
The effect of different genotype cattle grazing on the nutrient content of saline grasslands vegetation
Published December 28, 2018

Maintaining saline grasslands in good condition, preserving their yield and diversity is important not only for the purpose of nature conservation, but also for farming. Therefore, the primary purpose of our study is to analyse the effect of pasture use of the smaller weight extensive and the larger weight intensive beef cattle on the grassland... vegetation and nutrient content. In this way, we can answer the question whether grazing for nature conservation can be achieved with more profitable, more economical and more intense varieties.

The tests were carried out in May 2016 and May 2017, in the Hortobágy National Park (Pap-ere and Zám puszta), where a total of 16 sample areas were analysed. These areas are grazed with extensive beef cattle (Hungarian grey) and mixed genotype of intensive cattle. The associations were selected along a moisture gradient, such as wet salt marsh (Bolboschoenetum maritimi) and drier saline meadow (Beckmannion eruciformis). All the vegetative material collected both years in May was analysed for the following parameters: dry matter, crude protein, crude fibre and life-sustaining net energy content. We compared the effects of medium grazing (0.46 livestock/ha) and abandonment on vegetation and nutrient content.

We examined the effect of (i) grazing, (ii) different grasslands (salt marsh, saline meadow) and (iii) grazing of different cattle breeds (Hungarian grey, intensive beef) on the nutrient content of the vegetation of grasslands Based on our results, it was found that grazing had an impact on crude protein and life-sustaining net energy content. The highest crude protein content (12.75 m/m%) was obtained in the year 2017 in the area where higher density had been grazed for two years. For the lifesustaining net energy, the highest value (5.05 MJ/kg d.m.) was also obtained in 2017 and the lowest in 2016. Furthermore, it was found that there was no significant difference between the effect of the two cattle breeds on the parameters examined. Significant effects were observed only in the case of life-sustaining net energy: in the area of intensive beef cattle we received a higher value (5.15 MJ/kg body weight) than in the area with extensive beef cattle (4.96 MJ/kg body weight).

Our results have also shown that cattle grazing is of the utmost importance for the maintenance of both wet and mesophilous habitats. Based on our three-year study, we can say that grazing by both extensive and intensive cattle breeds is suitable for the management of saline habitats.

Show full abstract
Study of animal welfare status in dairy cow herds in Hungary – looking for causes of lameness
Published December 16, 2012

In the last 20–30 years lameness in cattle was found to be third the most influential disease next to mastitis and reproduction disorders. Studies have been established to explore reasons for lameness and prevention. The problem with more robust prevention plans is that knowledge and research evidence is not strong enough to run an effective ...prevention plan. The aim of the research is to look for reasons of lameness by observing number of cows on 6 farms during 2 lactations. Performance data will be put together to body condition score (BCS) and lameness scores. Other examination is focused on monitoring of 40 farms. This part of the project is more related to extension, collecting and sharing solutions for decreasing lameness. Producers are advised what kind of measures are possible to reduce occurrence of lameness. Effectiveness of those actions will be measured at the end of the study. The first preliminary results show lack in almost all preventive measures needed to be taken in minimising lameness. Those areas are related to poor facilities, lack of straw, problems with labour and basic management.

Show full abstract
Environmental Management Research on the Berettyó River
Published May 4, 2004

Our department is involved in ongoing research into the hydrological and ecological interplay of the Berettyó River.
In the first part of our study we classified the Hungarian section of the river from ecological and hydrological standpoints. We determined three typical parts of the river: a sandy and gravely bottom, a middle part with a sa...ndy and muddy bottom, and a lower part, with muddy bottom. In theese sampling areas we measured and established the more important static and dynamic hydrological, physical and chemical characteristics.
For the planned research we did a primary estimation of the environmental condition of theese sampling areas, on the basis of applicable biological and ecological indication methods.

Show full abstract
Evaluation of tree measurements after the reconstruction of tree-row system in five narrow streets of Debrecen
Published June 30, 2018

Viable urban environment is largely dependent on the size, condition and distribution of urban green spaces within and around cities. Treerows in streets are one of the most essential elements of urban green spaces. The aim of this study was to evaluate tree taxa compositions and lifespan values of trees in tree-row system with special referenc...e to five narrow streets (Garai, Jókai, Tanító, Csokonai and Zsák) of Debrecen. Tree numbers, tree taxa and the origin of tree taxa were determined in two years (2009 and 2017). As a next step, six selected taxa (Pyrus calleryana 'Chanticleer', Acer tataricum, Sorbus intermedia 'Browseri', Magnolia kobus, Acer platanoides 'Olmsted', and Crataegus x lavalleei 'Carrierei') were further estimated for the following lifespan parameters: i) trunk diameter (cm), ii) tree crown size (m), iii) trunk status (in 0–5 grades), iv) tree crown status (in 0–5 grades), v) estimated tree viability (in 0–5 grades), and vi) tree value in Ft. Our results showed that the numbers of tree taxa were 9 and 11 in 2009 and 2017 as well as an overall 279 and 282 trees were evaluated in 2009 and in 2017, respectively. More than 60% of the trees were native or similar to native taxa. The largest and the lowest trunk diameters were achieved for Pyrus calleryana 'Chanticleer' and for Acer tataricum, respectively. The largest and the lowest tree crown diameters were achieved for Acer platanoides ’Olmsted’ and for Magnolia kobus, respectively. The best and the worst trunk statuses by 2017 were achieved for Pyrus calleryana 'Chanticleer' and for Crataegus x lavalleei, respectively. The best and the worst tree crown statuses by 2017 were achieved for Pyrus calleryana 'Chanticleer' and for Acer tataricum, respectively. The best estimated tree viability status was achieved for Pyrus calleryana 'Chanticleer' and for Acer platanoides. Overall tree values were 2.73 times higher in 2017 compared to 2009. In conclusion, this study clearly demonstrated the importance of appropriate choice of tree taxa for an establishment of tree-row system in narrow street conditions.

Show full abstract
Study of animal welfare status in dairy cow herds in Hungary – looking for causes of lameness
Published November 20, 2011

In the last 20-30 years, lameness in cattle was found to be third the most influential disease next to mastitis and reproduction disorders. Studies have been established to explore reasons for lameness and prevention. The problem with more robust prevention plans is that knowledge and research evidence is not strong enough to run an effective p...revention plan. The aim of the research is to look for reasons of lameness by observing number of cows on 6 farms during 2 lactations. Performance data will be put together to body condition score (BCS) and lameness scores. Other examination is focused on monitoring of 40 farms. This part of the project is more related to extension, collecting and sharing solutions for decreasing lameness. Producers are advised what kind of measures are possible to reduce occurrence of lameness. Effectiveness of those actions will be measured at the end of the study. The first preliminary results show lack in almost all preventive measures needed to be taken in minimizing lameness. Those areas are related to poor facilities, lack of straw, problems with labor and basic management.

Show full abstract
SIM Samples Investigation by Statistical Methods
Published May 11, 2003

The assessment of the present condition of the soil is very important, because the accession of the number of the European Union members is in the near future. This can be the base of the modern agrarian environmental management programme. The assessment must be objective, detailed and analyse the processes in the soil.
Respecting the above ...causes was decided to create an Environmental Information Monitoring System. This system consists of more parts. One of them is the Soil Information Monitoring System (SIM). This system started to work in 1992.
This system has two functions. Creating and actuation is obligatory from the international contracts, on the other hand the public SIM has very important role in the conservation of the soil.
The SIM territorial measuring grid consists of 1236 measuring points. These points are representatives. The distributions of the points by the types of soil attend the variety of the types of soil of the country.
The investigated elements in 6 types of soil were in our experiment (the group of scandium and the lanthanide series elements). There are 6 elements above the detection limit (Gadolinium, Neodymium, Praseodymium, Scandium, Samarium, Yttrium).
The Neodymium concentration is 2 times higher than the content of Gadolinium and Yttrium.
The Neodymium concentration is 4 times higher than the content of Praseodymium, Scandium and Samarium.
In the case of Dysprosium, Europium, Lutetium, Terbium, Ytterbium the concentrations were below 1 mg/kg.

Show full abstract
The effect of irrigation on the yield and quality of maize (Zea mays L.) hybrids
Published May 20, 2020

In this study, the effect of water supply on the quality and productivity of different maize hybrids was observed.

Maize production is influenced by many agro-technical factors such as nutrient supply, plant density, environmental factors, water supply and temperature. Good soil quality and adequate technology significantly... reduce the unfavourable effect of crop year. The impact of fertilization, crop rotation, irrigation and plant density on maize yield was greatly affected by crop year and crop rotation. The main constituent (69–75% dry matter concentration) of maize seed is starch, however, its increase can be achieved only to a limited extent, as increasing the starch content will reduce other parameters, especially protein content. Significant nutrient content improvements can be achieved by appropriate hybrid-site connection and the use of adequate technology. Protein content reduction with optimal water supply can be positively influenced by the appropriate nutrient supply for the hybrid.

The experiments were carried out at the Látókép Experimental Site of Crop Production on calcareous chernozem soil. The weather of the examined year, which was partly favorable for maize and partly unfavourable in other respects, was also reflected in the development of maize and yields achieved.

In 2019, we were examining the hybrids of Kamaria (FAO 370), P 9903 (FAO 390), DKC 4351 (FAO 370) and KWS Kamparis (FAO 350–400). Due to the dry soil condition, sowing was delayed, however, the hybrids emerged ideally because rain arrived soon after sowing, which facilitated initial development. Young plants evolved rapidly and dynamically in the case of all hybrids. In terms of heat-demanding bread, the month of May was unfavourable to temperatures below the annual average, but the higher amount rainfall helped the development. However, due to the drier period in early July, 25–25 mm of irrigation water was applied to half of the experimental areas on July 1 and 15.

The aim of our research was to determine the best population density for hybrids under favourable soil conditions (calcareous chernozem soil). In both irrigated and dry conditions, a crop density of 75,000 crops were the most favourable for the Kamaria hybrid. The P9903 hybrid in the case of a crop density of 85 crops proved to be ideal and the DKC4351 had an optimal population density of 95,000.

However, it should be taken into consideration that, in the case of soils with poor water management, the drought sensitivity of the crop stand may increase at a population density of 95,000.

As a result of irrigation, yield increased and the difference between the examined plant numbers decreased. The yield growth was relatively moderate (341 kg ha-1 – 1053 kg ha-1), which makes the economicalness of irrigation doubtful in the given year.

Show full abstract
Alternatives of sewage sludge use in the crop production
Published May 16, 2012

The produced plants reduce the greenhouse effect because they fix CO2 that contributes to the causing of the greenhouse effect with about 50%. The production of fertilizers is not only a costly process but it needs a considerable energy at the same time. Nowadays, the reduction of the proportion of the fertilizer is significant. One ...of the reasons of this is that during the production such by-products are produced in a big quantity in which the necessary vegetal nutrients can be found in a considerable measure these enrich the organic matter of soil. The latter is essential condition for the microorganisms in the soil, without which the sustainable plant cultivation can not be achieved. Besides high prices of artificial fertilizers the utilization of the wastes is economically justified. Finally the other reason for the reduction of a usage of artificial fertilizer is that the wrong use of the fertilizer may cause environmental pollutions. I examined the cultivation application of the sewage sludge in laboratory circumstances during my work.

Show full abstract
Comparison of Reproductive Performance of the Roe Deer (Capreolus capreolus, L.) Among Different Regions
Published October 11, 2006

The potential and actual number of offspring of roe deer and the difference between these figures (prenatal and postnatal loss) significantly vary in each population yearly. The objective of this study is to examine the potential and actual number of offspring, the number of losses, and to find a link between the most important biological chara...cteristics of does (body weight – BW, condition – KFI) and the number of raised offspring on four territories on the Great Hungarian Plain.
Where the number of corpora lutea (CL) is the highest, there the losses are the highest as well, and the number of raised offspring is the lowest (region I.). Here, the rearing loss is double that of the weakest territory (region IV.). Rearing losses can be associated with the fenotype of does (BW, KFI) but environmental factors also have determinative importance. Where the number of twin-calving does was the highest, I found four times more does without a fawn than where the number of twin-calving does was the lowest. The nursing success was the best (the losses were lowest) in the region where the potential offspring (number of CL) was also the lowest, but the coverage of the habitat and the proportion of forests were largest. The food supply for the animals in autumn and winter are not enough, the structure of the habitat has to be improved as well, so that it might become adequate for game protection in extreme weather conditions.
The results have to be considered as preliminary ones. It is essential to continue and extend the research to increase the reliability of the results.

Show full abstract
Evaluation of dry matter accumulation of maize (Zea mays L.) hybrids
Published June 30, 2018

The increase of the grain yield of maize is closely correlated with its seasonal dry matter accumulation. Dry matter is accumulated into the grain yield during the grain filling period. The following maize hybrids were involved in the experiment: Armagnac FAO 490, Loupiac FAO 380 and Sushi FAO 340. In order to determine dry matter content, two ...samples per week were taken on the following days: 22nd, 25th, 28th, 31st August, 4th, 7th, 14th, 18th, 22nd, 25th, 29th September and 2nd, 6th, 9th, 13th October. In the course of sampling the weight of 100 grains from the middle section of 4 ears was measured in 4 replications. Dry matter content was determined after drying to constant weight in a drying cabinet at 60 °C. Harvesting was performed on 13th October 2017.

The daily precipitation sum was determined by local measurements, while the daily radiation and temperature data were provided by the Meteorological Observatory Debrecen of the National Meteorological Service in Budapest. Among the agrometeorological parameters, an analysis was made of the precipitation during the growing season, effective heat sums during the vegetative and generative phase, and the water supplies. The daily heat sums were determined using the algorithm proposed.

The amount of precipitation in the winter period before the 2017 growing season was 210 mm. The soil was saturated until its field capacity. The rather dry and warm March and April had a favourable effect, but there was no worthy amount of precipitation until May (51 mm) due to the condition of the dried seedbed. Sowing was performed on the 5th of May 2017 in a randomised small plot experiment. There was favourable precipitation and temperature during the growing season, thereby providing ideal conditions for maize development, growth and yield formation. There was near average amount of precipitation in each year. The total amount of precipitation in the summer period is 342 mm. Temperature was mostly above the average, but there was no long and extremely warm period.

The Armagnac hybrid reached its highest dry matter mass 126 days after emergence. Physiological maturity was reached sooner (on the 119th day) in the case of Loupiac, and even sooner in the case of Sushi (116th day). The thousand grain weight of Sushi (which has the shortest ripening period) was 286 g at the time of physiological maturity, while that of Loupiac was 311 g. Compared to Sushi, Armagnac showed 12 g more dry matter accumulation (306 g). In the case of all three examined hybrids, physiological maturity was preceded by an intensive phase, when the dynamics of dry matter accumulation was rather quick. On average, Sushi gained 2.8 g dry matter per day between 103 days following emergence and physiological maturity, while the same values were 3.2 g for Armagnac and 3.3 g for Loupiac. The aim of the regression line slope is to predict the behavior of the dependent variable with the knowledge of the values and characteristics of the independent variables using the regression line equation. Furthermore, to determine how the location affected the dynamic of dry matter accumulation in the Armagnac, Loupiac and Sushi hybrids. In regression analysis, the coefficient of explanation showed that the effect of day in the Armagnac was 97%, in the Loupiac 94%, in the Sushi 90 %. The determination coefficient (R2) is useful in determing how the regression equation fits. But, as we have seen, the determination coefficient alone is not sufficient to verify the model’s accuracy, in addition to the determination coefficient (R2), the normality of the data or the residuals, the variance of the variables at different levels, the independence of the data relative to time and non-oblique. Observations are evaluated for the correctness of the fitted model.

Dry matter values decreased evenly and slightly following physiological maturity. According to our research results, it was established that physiological maturity is followed by a moderate dry matter loss. Until harvesting, Armagnac lost 40 g of its thousand mass weight in 29 days, while the same value pairs were 69 g in 36 days for Loupiac and 29 g in 39 days for Sushi. Loupiac – which had the highest weight at the time of physiological maturity – lost the most of its dry weight; therefore, Armagnac and Sushi had higher values at the time of harvesting.

Show full abstract
Overview of the evolutionary history and the role in citric acid production of alternative oxidase
Published March 20, 2013

...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">All organisms are exposed to countless environmental effects, which influence in a disadvantageous way their life processes. They continuously adapt to the changing conditions and respond to the stress impacts by defence mechanisms. Through different signal transduction pathways they are able to increase or decrease the expression of their genes and consequently modify their metabolic processes. My interest focuses on alternative oxidase (AOX) enzyme whose expression is often increased under biotic and abiotic stress. The so far proven and putative functions of the AOX play a role in the ability of organisms to adapt to different conditions, such as heavy metals accumulation, pathogenic infection, oxidative stress and lack of oxygen or nutrients.

AOX is a member of the di-iron carboxylate protein family. Members of the di-iron carboxylate protein family are present in all kingdoms of life. They are considered to have ancient origin. It is believed that their sulfide-resistant and oxygen-reducing ability played a role in the survival of organisms during the transition between the anaerobic and the aerobic world. It is assumed that the AOX arose in eukaryotes through a primary endosymbiotic event, and this event made possible the development of mitochondria. Afterwords, vertical inheritance, and secondary and tertiary endosimbiotic events led to its spread among eukaryotes. It is assumed that bacteria obtained AOX by horizontal gene transfer from plants.

AOX-catalyzed alternative respiration plays an important role in the operation of energy-producing and biosynthesizing system of microorganisms. In these cases, the regeneration of reduced cofactors is an essential condition, and therefore may be rate-limiting for biotechnological processes, including the citric acid production.

Show full abstract
Tulip bulbs preparation by heat treatment for forced culture in green house
Published October 5, 2010

Tulip can be grown in parks as ornamental plant and cut flowers, or possibly in protected areas for cut flowers during winter and early
An important condition for the successful cultivation of tulips is the quality of the bulbs that are going to be planted and their
biological preparation.
Under the quality aspect bulbs have... to be uniform and large, preferably with circumference greater than 11 cm and must have good
phytosanitarical status.
Preparation of organic bulbs for ensuring the continuation of the differentiation process of germs (floral), is made during the storage.
It is known that the preparation of organic bulbs are made in interaction with environmental factors, among which temperature plays an
important role. At the beginning and throughout the process of biological preparation, temperature is maintained at a higher level then the
temperature must be low until planting.
The temperature level and the duration of treatment varies by followed objective respectively early or late flowering and staggered
flowers production over a longer period of time.

Show full abstract
Global Issues of RangelandManagement
Published September 5, 2002

Rangelands occupy about 50% of the world’s land area. They are ecologically and economically as important as rain forests and in even greater danger of degradation and disappearance. This paper reviews the definitions and distribution of rangelands and describes their global environmental importance in terms of erosion control, carbon storage... and methane emission. Condition and degradation of rangelands are defined and discussed and it is argued that soil protection and carbon storage can be increased and methane emission per animal decreased by conservative use and improvement of rangelands, whilst at the same time alleviating hunger and malnutrition in developing countries. It is concluded that policies should be adopted by national governments and international deve-lopment programs to conserve and improve rangelands.

Show full abstract
1 - 17 of 17 items