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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
83-87Views:275An 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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Lack of polymorphism of the agouti signaling protein (ASIP) gene among four different brown hare (Lepus europaeus Pallas 1778) populations
81-85Views:123The brown hare (Lepus europaeus Pallas 1778) is a common palearctic and a popular game species therefore it has been an obvious subject for population genetic studies since the second part of the 20th century. Among the several mitochondrial DNA studies some have been carried out concerning nuclear genes as well. The agouti signaling protein gene (ASIP) is involved in regulating the synthesis of eumelanin and pheomelanin in melanocytes of mammals. Though many studies focused on it in relation with several mammalian species, minimal information is available on this topic concerning the brown hare.
Here we present a short communication concerning the agouti signaling protein (ASIP) gene in four different country’s L. europaeus populations, namely Lithuania, Hungary, Serbia and Georgia. N=45 tissue samples have been investigated from overall 17 sampling sites of the different countries. There has not been found any polymorphism among the sequences. In an alignment with other Leporid species’ partial ASIP sequences downloaded from ENA we have found that based on a 178 base pairs long DNA sequence the haplotype of our samples contains three other Lepus species as well. This is concordant with the findings of a previous study focusing predominantly on the European rabbit (Orycto lagus cuniculus Linnaeus 1758) and the several mutations of its ASIP gene.
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The egg production of hungarian speckled hen and speckled transylvanian naked neck hen
11-15Views:75Our Faculty has been dealing with the cross-breeding of Hungarian speckled hen to maintain the breed since 1977. We keep two breeds of the Hungarian speckled hen, the bare-neck variant and the feathered-neck type on the pilot farm. Because of the spread of intensive poultry keeping the population of these breeds has become endangered. Beside the gene preservation, we endeavour to find the best way for the production-purpose
utilisation of the speckled hen stock. We examined the egg production of these breeds. -
Challenges and agroecological approaches in crop production
75-89Views:165Never has the need been greater for an ecosystem approach to agriculture. As our global population exceeds 9 billion in the next 30 years, with a concomitant demand for agricultural products, ever more pressure will be placed on our agricultural systems. Meanwhile, climate change is altering the ecological settings in which agriculture is practiced, demanding adaptation. Knowledge generated by long-term research will help to address one of the grand challenges of our time: how to meet sustainably the growing world demand for agricultural products – in a way that minimizes environmental harm and enhances the delivery of a diverse array of ecosystem services.
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Study of the Hejő brook watershed fish fauna
113-117Views:79Literature sources mention 18 fish species from the Hejő watershed. In order to learn more about the fauna, we studied the brook and its tributaries between 2003–2005. We detected a total of 32 fishspecies, 17 of which are new for the watershed. Most of these are native species (Rutilus rutilus, Leuciscus leuciscus, Leuciscus idus, Aspius aspius, Leucaspius delineatus, Gobio albipinnatus, Abramis bjoerkna, Abramis ballerus, Lota lota, Gymnocephalus cernuus, Sander lucioperca), but there are some adventive ones (Pseudorasbora parva, Carassius gibelio, Ameiurus melas, Lepomis gibbosus, Perccottus glenii) and a spontaneously immigrated species as well (Proterorhinus marmoratus).
Specific natural values of the watershed are the isolated population of minnow (Phoxinus phoxinus) in Kulcsárvölgyi Brook and the frequently occurring mudminnow (Umbra krameri) in the lower reach of Hejő Brook. -
Stevia (Stevia rebaudiana B.) yield in the case of different production technologies
71-77Views:186Stevia rebaudiana B. offers a natural alternative of sweetening, potential health promotion plant, and our country shows increased interest about cultivation in Hungary in addition to the neighboring European countries. The agricultural production system installation necessary
understanding of the needs of the plant, as well as exploring the agronomic potential. Field experiments were conducted in 2015 with the aim to highlight some of the technological production parameters and correlations between them. We have reviewed the most important agronomic factors, the spacing (50×50 cm and 33×33 cm), ground covering (agro-cloth covered and uncovered/ control), their vegetative growth (first-,second-order branch), herb yield and quality in effect.
Based on empirical evidence, that the Hungarian climates also have the opportunity of 3 cuttings during a growing season, besides of early planting, optimal climatic conditions (in October didn’t reduce the daily minimum temperature below 0 °C, after cuttings the maximum interval values remain below 40 °C), and adequate water supply and crop protection facility. The 33×33 cm spacing evaporates more than 50×50 cm spacing, because of the dense population, the continuous canopy less able to breathe, so there are serious chances to the pathogen colonization.
Based on the results of our research to the wider 50×50 cm spacing favorable appreciate the stevia optimal progress in terms of qualitative and quantitative parameters of the yield. The stevia yields produced in the Northern Great Plains field cultivation can produce similar results as stevia crop yields in warmer climates, where the primary crops. Our research experience suggest that there is a viable domestic stevia cultivation, developing the necessary technology is still growing further investigation justifies. -
The European Research Area: in quest of the Lisbon goals
73-79Views:68strong educational and scientific knowledge basie is one of Europe's traditional key assets that has made it possible for our continent to become world class in several research fields. Despite these great achievements, the position of the European research and technological development (RTD) potential is currently being challenged by a rapidly changing global competition, including the two main rivals, the US and Japan. The European Union (EU) is behind these countries as regards research and innovation output. Moreover, European research is faced with the
implications of globalisation of markets and industries, digitalisation and new technologies, as well as a need to address societal issues such as an ageing population or climate change.
At the same time, the European Union (EU) is facing the uneven distribution of RTD capacities and excellence within its own borders, especially the EU12 countries are lagging behind in this
respect.
In order to meet this twofold challenge the EU has to step up its efforts for the creation of a legitimate "European Research Area" that will make the EU more competitive on the international scene, and also encourage the less developed EU member states to invest more and better into research and innovation. -
The study of attitudes, prejudices and stereotypes towards the blind and people of visually impaired
61-66Views:121Living with visual impairment is not only a state but it is also a social connection. This relationship has two directions: on one hand it means belonging to the community of the blind and visually impaired, and on the other hand it means the lack of belonging to the healthy population. To study their situation and to tackle the issue of their social and work-related integration is an essential goal for this particular disadvantaged group as well as for the society. In my research I have examined how intensive and of what scale the emloyers’ attitude, stereotypes and prejudices towards the blind and visually impaired are. The research was centred around the measure of attitude, which was carried out with the help of an Osgood semnatic difference scale.
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Leaf protein analyses in order to utilise the leaf shoot of artichoke
43-47Views:130The constat growth of the Earth’s population brings with itself a higher demand for food and protein not only in human nutrition but also for the feeding of livestock. Currently, the feed industry is mainly built onseed-based protein, wherethebaseplant is soybean, which is large lycovered by imports in Hungary, similar toother European countries. However, the long-term economically sustainable lifestock breeding demandschanges which has also worked out strategies. An alternative protein sources could be green leafy plants.
In current work the Jerusalem artichokes as an alternative source of protein was studied, compared to alfalfa as a valuable protein plant. Our results indicate that fiber fraction ofJerusalem artichoke shootswas 34 to 37% after pressing in the autumn period while alfalfa slightly lower values were obtained (30%). On the other hand extracted green leaf protein concentration was higher in alfalfa than in Jerusalem artichoke. Along with this higher protein content could be measured from the leaf protein concentration of alfalfa and almost each amino acids were more, as well comparing to Jerusalem artichoke.
Overall, the alfalfa proved to be advantageous as expected both in leaf protein extraction efficiency, both regarding the content of the protein in the Jerusalem artichoke. However, considering aminoacid composition and green biomass production, Jerusalem artichokecould be a promisingplant species asplant protein sourceinthefuture.
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Harnessing diversity in durum wheat (Triticum turgidum L.) to enhance climate resilience and micronutrient concentration through genetic and agronomic biofortification
9-20Views:168Huge consumption of wheat-driven food products with low bioavailability and small concentrations of zinc is responsible for zinc-induced malnutrition and associated health complications. The contemporary durum wheat varieties have inherently tiny zinc concentrations in developing grain, which cannot meet the daily human zinc demand. Despite the fact that over two billion people are suffering from iron and zinc-induced malnutrition, various intervention measures have been deployed to reverse the effect of zinc-induced malnutrition on humans. There are evidences that agronomic and genetic biofortification approaches can increase grain yield and nutritional quality (i.e. zinc, iron, protein, and vitamins) of durum wheat to a greater extent. However, there is a lack of direct empirical evidence for which the influence of both biofortification approaches on improving human health. Application of micronutrient-containing fertilizers either in the soil or foliarly is effective in combination with NPK, organic fertilizers coupled with efficient durum wheat varieties, emphasizing the need for integrated soil fertility management (ISFM). Although genetic biofortification is a cost-effective and sustainable approach, agronomic biofortification provides an immediate and effective route to enhancing micronutrient concentrations in durum wheat grain. The application of zinc-containing fertilizers is more effective under drought conditions than in normal growing situations. Hence, this article provides a key information for agronomists and breeders about the potential of biofortification interventions to improve durum wheat yield and enrich the grain qualitative traits to ensure food and nutritional security of the ever-increasing world population.
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Comparison of Reproductive Performance of the Roe Deer (Capreolus capreolus, L.) Among Different Regions
41-46Views:81The 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 characteristics 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. -
Occurrence of woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) in Hajdú-Bihar county, Hungary
119-123Views:86Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) is native to East Asia, it spreads in several parts of the World and causes difficulties in plant protection, especially in maize. Difficulties in control of Eriochloa villosa originated from several reasons: seeds continue to germinate later in the season, significant part of seeds emerges from a deep layer of the soil, and the species is less susceptible to some herbicides applied to maize than other annual grass weeds.
The first report on the occurrence of woolly cupgrass in Hungary was published in 2008, and it reported about the appearance of this species near to Gesztely village (Borsod-Abaúj-Zemplén county), however, no information has been added about spread of the weed in Hungary until now.
A significant population was discovered next to Debrecen (Hajdú-Bihar county) in summer, 2011, and then weed associations were examined in maize, sunflower and stubble-fields on several km2 in the area to estimate the Eriochloa villosa infection. The weed species was found on every maize field bordering with a ground cover of 0.5-4%. Woolly cupgrass occurred inside of the 50% of maize fields, and reached a ground cover of 76% in case of most infected area, in addition it was found in sunflower and stubble-fields.
The spread of woolly cupgrass is expected in this area, which requires the consideration of this species in the planning of weed management technologies. -
Single nucleotide polymorphism analysis in meat-production related genes in broiler chickens
79-82Views:158In broiler chickens, the intensive selection for growth rate, feed efficiency, body composition (breast muscle weight) traits in the last decades was successful. To improve economically important characteristics, it is possible to use molecular markers associated with meat production traits. The aim of this study was to examine genotype polymorphisms in ROSS 308 broilers for thyroid hormone responsive Spot14α, insulinlike growth factor 1 (IGF1), IGF-binding protein 2 (IGFBP2), somatostatin (SST) and prolactin (PRL) genes. A further goal of this investigation was to study the relationship between the polymorphisms and phenotypic characteristics.
In the investigated broiler population, the frequency for CC homozygous genotype was 0.77 in Spot14α (AY568628), AA homozygous genotype was 0.80 in IGF1 (M74176), GG homozygous genotype was 0.85 in IGFBP2 (U15086), DD homozygous genotype was 0.60 in PRL (FJ663023 or FJ434669). Only the AA homozygous genotype was found in SST (X60191). Chickens with AC genotype in Spot14α, and with GG genotype in IGFBP2 had higher body weight (BW) and carcass weight (CW), compared to CC and GT genotypes. However, the differences were not significant (P>0.05). There was significant association (P<0.05) between PRL genotypes and body and carcass weight, where chicken with homozygous DD surpassed individuals with homozygous II genotypes.
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The recent state of cryopreservation techniques for ex-situ gene conservation and breeding purposes in small ruminants: A review
81-87Views:269The viewpoint of the recent cryopreservation techniques (CT) suggests the use of a reduced volume of cryopreservation solution, high concentration of cryoprotectants and ultra-rapid cooling and warming rates help to reduce cryo-injury and maximize the viability of the preserved animal genetic resources (AnGR). The CT had now become widely accepted as one of the best methods of choice for the ex-situ conservation of AnGR due to its high success rate recorded and no-invasive nature as compared to the conventional slow rate freezing (CSRF). Rapid advances and wide acceptability of the use of assisted reproductive technologies (ART’s) particularly artificial insemination (AI) in animal breeding had resulted in a greater loss of a large number of good quality genes in virtually almost all the native breeds of animals across the globe. Small ruminant (SR) animals are not an exception in such present predicaments situation of erosion and dilution of the valuable AnGR among the native breeds. As a result of this, 148 and 16 breeds of sheep and goats respectively have already become extinct in Europe and the Caucasus. In view of the aforementioned situation, the present review aimed at exploring some of the current states of development, roles played and potentials of CT in the conservation of SR genes and genome for the immediate and future breeding purposes for sustainable development. It basically covers; animal genetic resource, the need to conserve AnGR, tools for ex situ in vitro conservation of AnGR and recent developments in breeding and cryopreservation of SR AnGR.
Cryopreservation is playing a pivotal role in ex-situ gene conservation of AnGR. Decline in genetic diversity among SR breed population was high in Europe and the Caucasus. There is therefore, need for improvent on current stringent measures on conservation of AnGR in this region of the world.
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Examination of resistance against Aeromonas hydrophila infection on genetically different common carp variants (preliminary results)
7-11Views:75Septicemia disease caused by the bacterium Aeromonas hydrophila is a major problem for fish farmers around the world. In our experiment resistance to the disease was investigated on carp variants with diferent genetical backgrounds. 96 different genetic variants(„families”) were created by crossing various individuals of 4 carp strains (2 wild and 2 cultured ones). Families were reared until reaching the size of 10 gramms and 100 fish of each families were marked with an individual electronic identifier. Marked fish were divided into 5 groups. Fish from one group were infected with A. hydrophila and mortality were registered during 2 weeks. Based on mortality data, the most resistant and most susceptible families will be selected using population genetics methods.
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Experiences of organizing the social institutions into non-profit companies in Hajdú-Bihar county
99-102Views:85The study attempts to find solutions for relieving the major serious economic and social problems which are resulted partly by the economic crisis, mainly by demographic processes ( decrease of population, declining economic activity, ageing) and which occur all over Europe. In 2007, in Hungary, the Local Government of Hajdú-Bihar county started to reform the social institutions sytems in a unique way in the interest of operating these systems economically. The experiences, gained after the conversion, show that the companies as social institutions maintainers are able to work properly more efficiently, with less government support while they meet the professional requirements, and the management who does the control is competent
and innovative. -
The dynamics of biodiversity structure of soil microorganisms under the impact of biopreparations during potato growing season
67-74Views:141The use of biological preparations such as Phytotsid and Planryz contributes the increase of the general number of soil bacteria population by 13.0–36.1% in the case of potato variety Scarbnytsya and by 4.5–24.6% for potato variety Oberig compared with control. It also increases the number of saprophyte microflora, which compete with plant pathogens, micromycetes, and causes 1.2–1.8 times reduction in the number of soil fungi – Fusarium and Alternaria. During the application of Rovral Akvaflo the Shannon ecological index of species biodiversity is lower than during the biopreparation use. The decrease of species biodiversity was observed as well as strengthening the dominance of some species (dark pigmentation in fungi).
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Characterization of Water Resources in Transcarpathia
277-281Views:85Transcarpathia is located in one of the wettest parts of the Ukraine. There are 9429 rivers and creeks in the county with a total length of 19.86 thousand kilometers. The length of 152 rivers exceeds 10 km, 4 exceed 100 km (Tisza, Latorca, Ung and Borsava rivers). The average density of rivers is 1.7 km/km2, which is the highest in the Ukraine. The existing water resources are distributed unevenly in the county. The river with the greatest mass of water is the Tisza. Tisza carries 75% of all existing water resources, the remaining 25% is made up of the water in the river Ung and Latorca. Disregarding the uneven distribution of water resources, 80% of water is used up in the basins of the rivers Ung and Latorca from the water resources of the county, which leads to the overload of rivers.
The main sources of water supply in Transcarpathia: subsurface waters – for the population of cities and settlements, surface and subsurface waters – for the industry, surface waters – for irrigation.
In the interest of protecting existing water resources, it is required to follow current regulations, detecting and averting contaminating sources and establishing water conservation zones. -
Study of traditional folk foods from the point of view of nutrition in Hajdú-Bihar County
47-51Views:94Healthy nutrition is one of the major topics of our days. The occurrence of the so called “civilization diseases” is increasing continuously as a result of the changes in our nutritional habits and life-style. It was thought that folk nutrition at the beginning of the 19. Century had several beneficial effects on health. For this reason it was decided to study the food and nutritional habits of the population of Hajdu-Bihar County around the 1930s on the
basis of literary sources to see how well they do match with modern requirements of healthy nutrition. -
The effect of sowing date and plant density of winter oilseed rape (Brassica napus var. napus f. biennis L.) population
213-215Views:160The experiment has been set up in the University of Debrecen Látókép Experimental Station in three different years (2014, 2015 and 2016), three different plant densities 200, 350 and 500 thousand ha-1, four replications of the same nutrient supply with using a line spacing of 45 cm. In the experiment, the fore crop was winter wheat in each year. The amount of weeds was observed five times in the last experimental year (2016/2017). In the three experimental years, the highest yield was harvested from the early sowing plot with the highest plant density. On the basis of the Pearson’s correlation analysis there was significant negative correlation (r=-0.583) between the effect of the annual year and yield of the hybrid.
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A review on the trend of livestock breeds in Laos
227-237Views:307When the livestock sector is considered an essential role in farmers' livelihood, and local breeds are still the critical component of animal breeding in Laos. Thus, there is a need to review the previous, current situation and prospects for Laos' livestock production. It aimed to study the different traits among the existing dominant local and improved livestock breeds (cattle, pig, and goat) and a more in-depth study on the livestock sector's previous evolving and prospects. Our findings revealed that the general trend of livestock population in Laos increased year-by-year for over 45 years, except for 1995 to 2000. It was decreased by almost 22% due to the new national strategy on economic revolution. The first foreign breeds were introduced into Laos, i.e., Large White, Landrace, and Duroc in 1980, Red Sindhi bulls in 1998, the frozen semen of Red Brahman 2003, and Bach Thao goats between 2001 to 2003. Unfortunately, many data are still not precise for introducing other foreign breeds like Boer goats, Thai Grey and Red Brahman. There were many missing data on the improvement of livestock breeds in Laos, including the local and improved breeds' reproductive and productive performance, which needs more study and research. We conclude that the semi-complex farm operation should be applied to improve livestock breeding and their productions in Laos.
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The changes of the ichthiofauna of river Berettyó and tributaries
106-112Views:56In the spring and summer of 2005 I made ichtiologic research on the Barcau river in the area of Nusfalau – Saniob, as well as on its affluents.
The results obtained were compared to those of the previous research performed on the Barcau river and partially on its affluents. Wenoticed a decrease of the fish lot both from the qualitative and the quantitative point of view, although the oil industry -the main source of pollution from this area – is in a temporary regress.
Given the fact that upstream Suplacu-de-Barcau there are construction works for a dam and an artificiallakewhichwillinfluencetheriver fauna, the current research shall allow the repeat of the research and the comparison between the results, the identification of the effects of these works on the fish population from this area. -
Some basic problems concerning world animal production at the beginning of the XXI century
77-80Views:112The author summarizes the main new challenges facing animal agriculture: growing GDP in many countries increasing animal protein demand, bioenergy industry as a new player using potential food or feedstuffs, increasing demand, Growing water and land scarcity, weaking the position of plant agriculture, feed production. Forecasts are summarized regarding the magnitude of meat consumption increases, and the possible plant biomass quantities required additionally in the next 20 years to cover the needs of food, feed and biofuel on a global scale.
Efficiencies of various animal production sectors, poultry, pork, beef, mutton meat, milk and eggs and their environmental footprints are compared, summarizing the most important research results concerning UK, USA, OECD evaluations. Intensive systems using highly productive plant and animal population will play an even more important role in the future especially in poultry, pig, milk and aquaculture production system being efficient users of resources (feed, water, land) and the environmental foot print is smaller per unit product. -
The effects of drought stress on soybean (Glycine max (L.) Merr.) growth, physiology and quality – Review
19-24Views:189Abiotic stresses are one of the most limiting factors inhibit plant's growth, leading to a serious production loss. Drought stress is one of the most destructive abiotic stresses and is still increasing year after year resulting in serious yield losses in many regions of the world,
consequently, affecting world’s food security for the increasing world population. Soybean is an important grain legume. It is one of the five major crops in the world, an essential source of oil, protein, macronutrients and minerals, and it is known as the main source of plant oil and protein. Harvested area of soybean is increasing globally year after year. However, soybean is the highest drought stress sensitive crop, the water deficit influences the physiology, production and seed composition of this crop. We introduce a review for literatures concerning the changes of the above traits of soybean exposed to drought stress, with past explanations for these changes. -
Inheritance of Plant and Ear Height in Maize (Zea Mays L.)
34-38Views:377Plant and ear height are very important characters not only for describing new varieties of maize (Zea mays L.), but for green and dry matter production, and even for grain yield. Significant positive correlations have been reported by various authors between plant height and stover yield, plant height and dry matter yield, and plant height and grain yield. The height of the main ear is also correlated to plant height. It depends on the variety or the environment, but is likely to be the same height within a population. Many environmental and agronomical factors (e.g. plant density, fertilization, pests and diseases) influence the expression of these characters, which are not quality traits. Their expression is controlled by many genes and by the interactions between these genes. The heritability of these traits is high and they show significant genotypic variability and positive heterosis, as reported in many research publications.