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The Impact of Water Supply on the Quality and Health of Potato
144-147Views:103Besides its effect on potato yield, water also has a significant impact on yield quality. Excess water (too much precipitation, over-irrigation) and the lack of water (lack of precipitation or irrigation) both trigger stress in the plant and can significantly worsen the quality of the yield (seed potato) and deteriorate the health of the plant and the seed potato. Excess precipitaton or irrigation water leaches nitrate-nitrogen under the rhizosphere, consequently, the amount of available nitrogen decreases leading to the deficiency of N in potato. If water cover (the maximally saturated state of soil) exceeds 8-12 hours, it can cause root destruction (because of the lack of oxygen), which leads to the wilting and later to the death of the plant. Abundance of water caused by excess precipitation or irrigation is a major problem primarily on sandy loam, loam and clay loam soils with bad structure and water management qualities, but also on any soils, which are over-irrigated or irrigated at an improper time. Symptoms of the lack of water are detectable mostly when the available water content of the soil (disponible water) decreases under 60-65%.
In the present year, there was a lack of precipitation on the Great Plain, which can be compensated by proper irrigation. Unfortunately, this problem is further intensified by the high temperature, which results in faster ripening and accompanied with fluctuating soil moisture content, in the formation of secondary tubers. -
Influences of water deficiency on the productivity of young plants at different sites
371-378Views:120Water deficiency has become one of the most limiting factors of crop production in Hungary as the tendency in annual amounts of precipitation shows a decreasing tendency; therefore, it has become similar to those of Southern Europe. The most significant decrease in precipitation occurs typically during spring, approximately 20% of the data expressed in the averages of the last century. Studying the relationship between water deficiency as a stress factor and nutrient supply is important in order to improve the production efficiency of crops. Nowadays, this problem receives outstanding attention presented in numerous papers both in Hungary and globally, however, there are several questions yet to be answered. Our pot experiments were carried out under controlled greenhouse conditions in order to establish new data on these relationships. Experimental soils were typical for Western Transdanubia, taken from long-term field experiments representing four different site characteristics of the region. It was concluded from the results that drought periods during the early growth stages (i.e. 4–5 weeks after emergence) of plants may result in significant decreases in both dry matter production, nutrient concentrations, nutrient uptake and shoot:root ratios. Better nutrient supply, especially potassium, plays a significant role in reducing the negative effects of water deficiency.
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Application of mycorrhizae and rhizobacteria inoculations in the cultivation of processing tomato under water shortage
111-118Views:45The effect of mycorrhizal fungi and plant growth promoting rhizobacteria on some physiological properties, yield and soluble solid content (Brix) of ‘Uno Rosso’ F1 processing tomato was studied under water scarcity. Inoculation was performed with mycorrhizal fungi (M) and rhizobacteria preparation (PH) at sowing (M1, PH1) and sowing + planting (M2, PH2). The treated and untreated plants were grown with regular irrigation (RI = ET100%), with deficit irrigation (DI = ET50%) and without irrigation (I0). In drought, the canopy temperature of plants inoculated with arbuscular mycorrhizal fungi (M1, M2) decreased significantly, however, the decrease was small in those treated with the bacterium (PH1, PH2), while the SPAD value of the leaves of plants treated only with Phylazonit increased significantly. On two occasions, inoculations (M2, PH2) significantly increased the total yield and marketable yield, however, under water deficiency, a higher rate of green yield was detected than untreated plants. In dry year using deficit irrigation, the one-time inoculation (M1, PH1) provided a more favorable Brix value, while the double treatments reduced the Brix. In moderate water scarcity, the use of mycorrhizal inoculation (M2) is preferable, while under weak water stress, the use of rhizobacteria inoculation (PH2) is more favorable.
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Effect of plant growth promoting Rhizobacteria (PGPRS) on yield and quality of processing tomato under water deficiency
19-22Views:173Chlorophyll fluorescence was measured of H1015 tomato hybrid with different bacterial treatments (B0–B1–B2–B3) and three irrigation treatments: regular irrigated (RI), deficit irrigated (DI) and non-irrigated conditions (I0). The aim of the experiments was to show the effects of plant growth promoting rhizobacteria on the yield, dry matter and vitamin C content of processing tomato during different irrigation treatments, and measuring the chlorophyll fluorescence during the ripening and development stages. According to the results, none of the bacterial treatments had a statistical effect on the quantity and quality of the tomato and on the chlorophyll fluorescence, only the irrigation. Further studies are needed.
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The impact of applying foliar fertilizers on the health condition of maize
105-109Views:158The 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 leads 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.
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Assessment of Environmental Susceptibility/Vulnerability of Soils
62-74Views:86Soils represent a considerable part of the natural resources of Hungary. Consequently, rational land use and proper soil management – to guarantee normal soil functions – are important elements of sustainable (agricultural) development, having special importance both in the national economy and in environment protection.
The main soil functions in the biosphere are as follows: conditionally renewable natural resource; reactor, transformer and integrator of the combined influences of other natural resources (solar radiation, atmosphere, surface and subsurface waters, biological resources), place of „sphere-interactions”; medium for biomass production, primary food-source of the biosphere; storage of heat, water and plant nutrients; natural filter and detoxication system, which may prevent the deeper geological formations and the subsurface waters from various pollutants; high capacity buffer medium, which may prevent or moderate the unfavourable consequences of various environmental stresses; significant gene-reservoir, an important element of biodiversity.
Society utilizes these functions in different ways (rate, method, efficiency) throughout history, depending on the given natural conditions and socio-economic circumstances. In many cases the character of the particular functions was not properly taken into consideration during the utilization of soil resources, and the misguided management resulted in their over-exploitation, decreasing efficiency of one or more soil functions, and – over a certain limit – serious environmental deterioration.
Soil resources are threatened by the following environmental stresses:
– soil degradation processes;
– extreme moisture regime;
– nutrient stresses (deficiency or toxicity);
– environmental pollution.
Environmental stresses caused by natural factors or human activities represent an increasing ecological threat to the biosphere, as well as a socio-economic risk for sustainable development, including rational land use and soil management.
The stresses are caused by the integrated impacts of various soil properties, which are the results of soil processes (mass and energy regimes, abiotic and biotic transport and transformation and their interactions) under the combined influences of soil forming factors. Consequently, the control of soil processes is a great challenge and the main task of soil science and soil management in sustainable development.
The efficient control of these processes necessitates the following consecutive steps:
• registration of facts and consequences (information on land and soil characteristics, land use, cropping pattern, applied agrotechnics, yields, with their spatial and temporal variability);
• evaluation of potential reasons (definition and quantification of soil processes, analysis of influencing factors and their mechanisms);
• assessment of the theoretical, real, rational and economic possibilities for the control of soil processes (including their risk-assessment and impact analysis);
• elaboration of efficient technologies for the „best” control alternatives (best management practice).
Scientifically based planning and implementation of sustainable land use and rational soil management to ensure desirable soil functions, without any undesirable environmental side-effects, require adequate soil information. In the last years such data were organized into a computer-based GIS soil database in Hungary, giving opportunities for the quantification, analysis, modelling and forecasting of the studied environmental stresses and for the efficient and scientifically based prevention, elimination or reduction of environmental stresses and their unfavourable ecological and economical consequences.
Special attention was paid to the assessment of various soil degradation processes, as: (1) soil erosion by water or wind; (2) soil acidification; (3) salinization and/or alkalization; (4) physical degradation (structure destruction, compaction); (5) extreme moisture regime: drought sensitivity and waterlogging hazard; (6) biological degradation; (7) unfavourable changes in the plant nutrient regime; (8) decrease of natural buffering capacity, (9) soil (and water) pollution.
The actions against undesirable environmental stresses and their unfavourable consequences are important elements of sustainable, efficient, economically viable, socially acceptable and environmentally sound crop production and agricultural development. These are joint tasks of the state, decision makers on various levels, the land owners, the land users and – to a certain extent – of each member of the society. -
Untersuchungen zur Phosphataufnahme von Zwischenfrüchten bei unterschiedlicher P-Versorgung des Bodens (Investigation of P Uptake of Catch Crops under Different P Supply)
7-14Views:176The P uptakes of 11 different catch crops on four soils were estimated and compared with changes of double lactate soluble Phosphorus (P(DL)) in soil within a vessel trial. Additionally a model trial with quartz sand was carried out for investigations of the influence of P supply on root parameters. The differences of P uptake in dependence of the proofed variants were significant. Under a sufficient P supply Buckwheat, Maize and Oil radish had the highest P uptake on sandy soils, on loamy soil also Buckwheat and Maize but Serradella too. Under P deficiency the withdrawals of Phosphorus for Buckwheat, Maize and Oil radish were found to be the highest. In contrast to the sandy soils for the loamy soils no significant relation between the P uptake by plants and changes in the P-DL amount in soil could be found. For all variants the P uptake by plants were higher than the reduction of the P-DL amount in soil. The rate of P-DL content on the total P content in soil reduced while the two trial years only in sandy but not in loamy soils. The P uptake, the root length and the root/shoot relationship depends significantly on the cultivated crop and the added P compound. The added water soluble KH2PO4 caused a higher P uptake but a lower root/shoot-relationship than the water insoluble P compounds.
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Site and hybrid-specific agrotechnical models in sweet corn production
105-108Views:92The effect of three agrotechnical factors (sowing time, fertilization, plant density) and two genotypes on the crop yield of sweet corn was examined on chernozem soil in the Hajdúság region in two different crop years. Compared to the 30-year average, the climate was dry and warm in 2009 and humid in 2010. The experiments were conducted at the Látókép Research Site of the University of Debrecen. In the experiments we applied two sowing times (end of April, end of May), six fertilization levels (control, N30+PK, N60+PK, N90+PK, N120+PK, N150+PK) and two crop density levels (45 thousand ha-1, 65 thousand ha-1). The hybrids we used were Jumbo and Enterprise. As regards the requirements of sweet corn production, the crop year of 2009 was dry and warm. The effect of moisture deficiency was more adverse on the crop yields with the second sowing time. On the contrary, the other examined year (2010) was significantly humid; the precipitation was 184 mm above the 30-year average and the temperature was average.
In the dry and hot crop year, the best yields were obtained with the hybrid Jumbo (25677 kg-1) at 65 thousand ha-1 plant density level on the average of the fertilization levels. The crop yields of Enterprise were also the highest at high plant density level (24444 kg ha-1). With the second sowing time the highest yields were obtained at the higher plant density level (65 thousand ha-1) with both hybrids (Jumbo 18978 kg ha-1, Enterprise 18991 kg ha-1), which confirmed the good adaptation capability of these hybrids at high plant density level. In humid crop year with early sowing time the highest yielding hybrid was Enterprise (at 45 thousand ha-1 crop density level 20757 kg-1), at the same time, Jumbo was best yielding at the higher plant density level (18781 kg-1). With the second sowing time the highest crop yield was obtained with Enterprise again (20628 kg ha-1 at 65 thousand ha-1 plant density level). With this sowing time the average yields of Jumbo, was 18914 kg ha-1 respectively. We found that dry crop year and early sowing time provided the best conditions for sweet corn production; the highest yields were obtained under these circumstances, which might be the results of the outstanding water management of chernozem soils. -
Physiological traits and yield of three soybean (Glycine max (L.) Merr.) genotypes as affected by water deficiency
11-15Views:179Soybean is a very important legume; it has the highest protein content, and it is a very important source of vegetable oil. Soybean is droughtsusceptible, and drought is one of the major abiotic stresses that has been increasing over the past decades as a result of the global climatic changes. To evaluate the influence of drought stress, three soybean genotypes were grown under rainfed conditions, and compared to irrigated controls. The obtained results showed that the chlorophyll content, leaf area index and plant height decreased under drought stress conditions, which led to noticeable and sometimes significant yield reduction. Our results suggest more specific studies on the physiological changes of the local soybean genotypes under drought stress to better select the adopted ones.