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The role of leaf area and photosynthesis in optimising the sowing date of maize
5-10Views:120Our sowing date experiment took place in the Demonstration Garden of Institution of Plant Sciences, Agricultural Center of University of Debrecen, in 2012–2014. The thesis contains data of test year 2014. Our purpose, besides several other examinations, was to observe how sowing date influences leaf area index and activity of photosynthesis of maize hybrids, and how those factors affect fruiting. In the experiment we monitored the change of the leaf area index and the photosynthesis of hybrids with four different growing seasons.
Based on the results, it can be concluded that most of the examined hybrids reached their smallest leaf area with the third sowing date and with the highest yield results. Hybrid Da Sonka had the largest leaf area (4.10 m2 m-2), and hybrid DKC 4590 produced the highest yield (13.16 t ha-1)
with the third sowing date.
During testing the photosynthetic capacity, the extremely high performance of the youngest plants with the third sowing date is outstanding, which can be explained by the different ripening periods. Examination of the correlation between the photosynthetic capacity and the yield, by linear regression analysis, also proves that photosynthesis has a determinative role in fruiting.
The results obtained confirm that not only the environmental and agricultural factors in the growing season have effect on the yield, but also other factors like the leaf area index and the photosynthesis are determinative parameters, and all those factors together, modifying effects of each other, develop average yields.
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Changes of relative chlorophyll content at maize smut inoculated hybrids
55-58Views:223The leaf chlorophyll content analysis is important for several reasons. The natural or anthropogenic stressors directly effect on the chlorophyll content. Through the measurement of the chlorophyll content it is possible to obtain data concerning the physiological status of the plant, moreover the chlorophyll content is closely related to the nitrogen content, so it is linked to photosynthesis and the photosynthetic activity which determine biomass production.
One of the most common symptoms of plant diseases is the larger and smaller interveinal chlorotic areas. These might be local, or expand to the whole plant. There are multiply reasons of chlorosis such as reduction of chlorophyll content, unfavorable effects on the chlorophyll content,disorders regarding function of chloroplasts or ultimately destruction of the chloroplasts. Although such a chlorotic deviancy can contribute to significant losses in photosynthesis; however the underperformance photosynthesis of the sick plants is a more complex process.
As we unambiguously experienced during our investigations on common smut that the infected maize plants most common accompanying symptom was chlorosis on the leaves, so it is especially important to examine how the infection influenced on the chlorophyll content of different hybrids. -
The effect of copper fungicides on the rate of photosynthesis and the transpiration of hop plants
117-123Views:84The paper evaluates the effect of copper fungicide spraying on the rate of photosynthesis and transpiration of hops, the influence of spraying on the elemental copper content in the leaves and cones hop variety Agnus. Photosynthetic rate was measured by LC pro+ (infrared analyzer) in the Hop Research Institute Saaz in the field in some periods of 2008, 2009 and 2010. Dry cones and leaf samples (taken before and after application of copper fungicides) were analyzed in an accredited laboratory for elemental copper.
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Physiological plasticity of main tree species of lowland hornbeamoak forest as a results of forest gap regeneration
99-103Views:161Specific leaf area (SLA) of English oak (Quercus robur L.) and hornbeam (Carpinus betulus L.) as members of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the inert forest. The artificial opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important ways for plant life and plant production basically influenced by altered light condition resulted in opening process. Efficient photosynthesis is important for plant life, plant production, but species-dependent plasticity of photosynthesis makes one species more tolerant, than others. The specific leaf area is acceptable parameters for characterising plant production, dry matter content and leaf structure. The dry matter content based on known leaf area is higher in oak both sun and shade leaves, than hornbeam. The different place of leaves in the canopy of trees did not influence the values of SLA.
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Analysis of the photosynthetic parameters, the yield and the quality of winter wheat
101-106Views:125The environmental adaptability of crop production is basically determined by the selection of biological background (plant species and
varieties) suitable for the region and the site. The aim of our work is to parametrize the plant assimilation, its intensity, dynamics and the
most important characteristics and the relationships to the quality in winter wheat trials. The measurements were carried out at the research
site of the University of Debrecen in small parcel experiments. We measured the leaf net CO2 assimilation rate, stomatal conductance,
intercellular CO2 level, the transpiration, the leaf temperature and the air temperature by the LICOR LI-6400 portable photosynthesis
system in field trials on the nutrient supply. The soil of the experimental area is calciferous chernozem with favorable water regime.
We have examined the photosynthetic activity, the productivity and yield stability of winter wheat varieties. We have compared the yield
results, at similar agrotechnical conditions in seven cropyears. We also determined the quality parameters of the winter wheat varieties.
Then we valued the yield stability of genotypes with the help of analysis of variance and linear regression equations. We have defined the
connections between assimilation parameters, the yield stability and quality parameters of wheat varieties. -
Seasonal changes of photosynthetical parameters as a results of forest gap model
133-136Views:131Photosynthetic parameters of English oak (Quercus robur L.) as a member of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the host forest. The artifical opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important way for plant life and plant production. In the centre of photosynthetic efficiency the quality and quantity traits of photosynthetic pigments are standing. During our work some photosynthetic parameters of plants (in the gap and in the forest as well) were measured: relative chlorophyll content as SPAD index, chlorophyll a and b content, total chlorophyll content and ratio of chlorophyll a and b. Based on our results no significant differences among our data in early spring. Although, during the summer significant differences occurred between the measured values in the gap and in the forest area. Lower total chlorophyll content was experienced in the gap, than in the forest area due to the lower chlorophyll-b content. Because of the high light intensity higher chla/chlb ratio was measured in the gap. The lower chlorophyll contents of gap habitat may have a part of the acclimatization process of photosynthetic apparatus against high light stress, which can determinate the survival chance of individual.
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The effect of season and fertilizer on the LAI, the photosynthesis and the yield of the maize hybrids with different genetic characteristics
27-34Views:72The experiment was carried out in Debrecen, at the Experimental Station of the University of Debrecen Centre of Agricultural Sciences, Department of Crop Production and Applied Ecology. We tested 10 various hybrids with their own genetic characteristics for five different fertilizer doses, in addition to the parcels without fertilization. The three factors of production technology jointly determine the successfully of maize production, but in different measure. The yield and the stability of yield of maize can be increased with hybrid-specific technologies.
In 2004-2005 experiment years the favorable results reached were due to the rainy season. There were significant difference between the productivity of maize hybrids. The N 40, P2O5 25, K2O 30 kg/ha treatment caused the highest increase of yield (3-5 t/ha) compared to the control (parcels without fertilization). The reaction of hybrids to the further fertilizer doses was different. The agro-ecological optimum of NPK fertilization was N 120, P 75, K 90 kg of the most hybrids.
During the experiment, we tested the moisture loss of the five hybrids. The seed moisture content at harvest was higher than in previous years due to the rainy seasons. The seed moisture content of harvest of FAO 200-300 hybrids were about 20%. It changed between 21-24% in the case of hybrids with longer vegetation period (FAO 400), the seed moisture content of Mv Vilma (FAO 510) was 24.21-25.04% in the average of fertilizer treatments. There is an important difference between the moisture loss ability of hybrids which changed 0.2-0.6%/day. The moisture loss of hybrids changed depending on the fertilizer treatment; usually, it was more favorable in the optimal fertilizer dose (N120+PK).
In the case of tested hybrids, we measured the highest LAI and photosynthetic activity at the optimal treatment, N 120, P2O5 75, K2O 90 kg/ha in the respect of efficiency and environmental protection, and the yield was high also for this treatment. There are significant difference between the LAI, the photosynthetic activity and the yield of hybrids, and these values could change depending on the treatment of fertilization. -
Comparative study of newly-bred black locust clones with regard to photosynthetic rate and water use efficiency: early evaluation
5-10Views:199Black locust (Robinia pseudoacacia L.) is one of the most important tree species in Hungary, due to its positive economic impacts. Research to increase its yield, improve its stem quality and enhance its drought tolerance has been ongoing since the 1960s. Of the current research works in this field, the clone trial of the Forest Research Institute, University of Sopron, established in 2020 in the Nyírség region, is worth highlighting. In this experiment 4 newly-bred clones and a state-approved black locust cultivar ('Üllői') are being tested. In the summer of 2022, ‘on site’ measurements of assimilation parameters – net assimilation (An), transpiration (Tr) – were carried out using the LI-6800 portable photosynthesis system. From the data obtained, the water use efficiency (WUE) was calculated. The results of the statistical analysis (Kruskal-Wallis H test) have shown significant differences (p < 0.05) between the clones for all three parameters (An, Tr, WUE) tested. The NK2 clone has performed the highest value for all the parameters studied. However, no significant differences were found between clones NK2 and PL040 for Tr or between NK2 and control ('Üllői') for WUE. Studies of this kind contribute to the improvement of black locust growing through the production and selection of cultivars, which are relatively resistant to the negative effects (drought) of climate change.
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The effects of water supply on the physiological traits and yield of tomato
25-30Views:148The SPAD value, the chlorophyll fluorescence and the canopy temperature of the leaves and fruits of tomato hybrid “H1015” were investigated under non-irrigated (I0), deficit irrigated (I50) and well-irrigated (I100) conditions. The aim of the experiments was to show which treatment effect on the examined traits affected photosynthesis, leaf temperature and yield quantity, as well as quality under water scarcity. In the control treatment (I0), the canopy temperature increased, but the SPAD decreased compared to the other two treatments (I50 and I100). Chlorophyll fluorescence produced a fluctuating result. In the end, the number of the fruits was high, but the number of the sick and green berries was increased.
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Effects of plant density on photosynthetic characteristics and yield of maize under irrigation condition
115-118Views:280Maize plant response to plant density is an essential agrotechnical factor used for determining grain yield. Three plant densities (60,000 ha-1, 72,500 ha-1, and 85,000 ha-1) were used in this study to ascertain the effect of photosynthetic parameters and grain yield. Results show a significant difference in the photosynthetic parameters (SPAD, NDVI, LAI) and plant height for plant density of 85,000 ha-1. Grain yield and stem diameter were not significantly affected between the different plant densities.
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Comparison of the physiological responses of an oil-pumpkin cultivar and hybrid under different nitrogen supply conditions
65-69Views:177Cucurbita pepo var. styriaca is known as a medicinal crop among other cucurbits. The benefits of cucurbits fruits are very important in terms of human health, purification of blood, removal of constipation, digestion and supplying energy. The mutant styrian oil-pumpkin (Cucurbita pepo L. convar. Pepo var. styriaca Greb.) exposes a complete lack of lignification of the seed testa. For this reason, this kind of naked pumpkin seed is more consumable as snack than other seeds. The vegetative growth of plants is crucial for fruit production. Nitrogen is the most imperative element for the proper vegetative growth and development of plants which significantly increases and enhances yield and its quality by playing a vital role in the biochemical and physiological functions of plants.
Field studies were conducted to study the effect of nitrogen nutrition on certain physiological parameters and their differences between the styrian oil pumpkin hybrid and cultivar (Gleisdorfi Classic cultivar and GL Rustical hybrid). The small block experiment was carried out based on a factorial experiment with a completely randomised block design and four replications in the Research Institute of Nyíregyháza during the summer period of 2017 and 2018. Three different concentrations of nitrogen fertiliser was applied at sowing. Photosynthetic pigments (chlorophyll-a, -b and carotenoids) were analysed as one of the basic factor of efficient photosynthesis. The yields of two genotypes were also measured in all treatments as seed-weight. The contents of photosynthetic pigments were higher in the oil-pumpkin hybrid, mainly the carotenoids in 2018. The vegetation period of 2018 was drier than in 2017, the hybrid oil-pupmkin was more efficient in stress tolerance than the cultivar with higher carotenoids pool. The obtained yield was more pronounced in the oil-pumpkin hybrid than the cultivar in all examined years. The hybrid GL Rustical was more sensitive to nitrogen treatment than the cultivar Gleisdorfi Classic.
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Calculating possibility of the leaf area index of apple and pear trees
229-233Views:110A 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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Responses of pea (Pisum sativum L.) to the rising atmospheric concentration of carbon-dioxide
185-188Views:169The atmospheric concentration of carbon dioxide increases from decade to decade in increasing pace. In 1957, atmospheric carbon dioxide levels were around 315 ppm, while in 2012 it amounted to 394.49 ppm concentration. In parallel, the global temperature is rising,which is projected to average 1.5–4.5 °C. The carbon dioxide concentration is a key factor – in interaction with the light – affects the plant's photosynthesis. Among the various factors significant interactions prevail: environmental factors affect - the growth and the development of plants, leaf area size and composition, the function of the photosynthetic apparatus, the duration of growing season.
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The effect of drought and cropping system on the yield and yield components of maize (Zea mays L.)
51-53Views:122Different Cropping Systems have many advantages and ensure better crop growth and yielding. Its combination with other agronomic measures can ensure optimal crop density for maximum crop growth and photosynthesis efficiency. The aim of this study was to investigate the influence of different cropping systems on monoculture and biculture rotations [maize- wheat]. The study found that crop rotation does not have a significant effect on the grain nutrition quality, Leaf Area Index (LAI) and Normalized Difference Vegetative Index (NDVI) but has a significant effect on the Soil-Plant Analysis Development (SPAD). Yield and yield components were significantly influenced by crop rotation in this study as yield, plant height, cob weight and number of grains per row all recorded lower mean at 5% probability levels.
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Evaluation of water balance in apple and pear trees
193-198Views:102A 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. Furthermore we defined from the water balance of compensation lysimeters the cumulative transpiration of
fruit trees and the efficiency of water use of trees. -
Water managed properties of apple and pear trees based on lysimeters
129-132Views:135A significant proportion of the aboveground green and dry weight of the plant is constituted by foliage. The canopy is an important factor of plant growth. On the one hand, the canopy absorbs solar energy, which is necessary for photosynthesis; on the other hand, it accumulates the nutrients absorbed by the roots, and most of the water-loss occurs through the foliage. 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 the ADC AM 100 leaf area scanner, we determined the k-value, with which we can easily and fast evaluate the leaf surface. Furthermore, we defined from the water balance of compensation lysimeters the cumulative transpiration of fruit trees and the efficiency of water use of trees. From the examined trees were made a 3D depiction, which show the shape, branching and the location of trees.
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Effect of bacteria containing bio-fertilizer on Cd-tolerance of corn and sunflower seedlings in nutrient solution
15-21Views:70Bio-fertilizers promote the nutrition uptake, firstly enhance the baring and mobility of nutrients, on the other hand biofertilizers elevate nutrient uptake in direct way. Although there are a lot of questions about their application in polluted soils. The cadmium ion is easily collectable and also transportable inside plants. Thus the Cd can get into the food-chain causing public health problems. The cadmium treatment decreases the dry matter accumulation, and the intensity of photosynthesis at the experimental plants, while the treatments with bio-fertilizer increased these parameters. The cadmium accumulated in the roots, the transport to the shoots was low. We came to the conclusion, that –because of the different nutrient-uptake systemthe sunflower took up more cadmium. Using bacterium containing bio-fertilizer the toxic effect of cadmium was moderated. By our experimental results the use of Phylazonit is offered under contaminated conditions.