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Atmospheric CO2 concentration, light intensity and nitrogen nutrition affect spring barley response to drought and heat stress
Findurová, Hana ; Veselá, Barbora ; Opoku, Emmanuel ; Klem, Karel
The aim of this study was to compare physiological responses of two spring barley varieties,\ndiffering in their oxidative stress tolerance, to drought and heat stress after pre-treatment under different\nirradiation regimes, CO2 concentrations, and nitrogen fertilisation levels. High light intensity, elevated\nCO2, and additional UV radiation increased flavonoid accumulation. Moreover, more flavonoids were\ninduced in oxidative stress-sensitive variety Barke. Combined drought and heat stress caused a large\ndecline in CO2 assimilation, whereas heat stress alone caused only minor changes. Under combined\nstress, plants grown under low light intensity and no UV irradiation performed the best despite their\nhigher initial water use efficiency and lower flavonoids content.
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Modelling the onset of phenological phases of spring barley (Hordeum vulgare L.)
Dížková, Petra ; Bartošová, Lenka ; Hájková, L. ; Balek, Jan ; Bláhová, Monika ; Bohuslav, Jakub ; Pohanková, Eva ; Trnka, Miroslav ; Žalud, Zdeněk
The onset of phenological phases of plant species is influenced mainly by air temperature. Each phenophase has its temperature limits (base temperature and temperature sum), which must be reached for each phase to occur. With knowledge of these limits, it is possible to predict the onset of phenological phases in localities where only meteorological data are available and also in future climate conditions. In this work, we used phenological ground-based data from 33 stations within the Czech Republic to calculate the most relevant meteorological predictors. PhenoClim software was used for phenological and meteorological data calibration and modelling. The smallest error that allows us to predict the term of the phenophases was found for the heading of spring barley (Hordeum vulgare L.), as the best predictor was the maximum daily temperature and the statistical error was 3.6 days.
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Yield formation parameters of winter wheat under two CO2 levels in water sufficient and depleted environment
Hlaváčová, Marcela ; Klem, Karel ; Veselá, Barbora ; Findurová, Hana ; Hlavinka, Petr ; Smutná, P. ; Horáková, V. ; Škarpa, P. ; Trnka, Miroslav
Agricultural production faces with ongoing climate that in Europe takes form of changing seasonal precipitation pattern with more frequent drought spells. These changes come on top of rising air temperature and did and will affect productivity as well as onset and duration of key developmental stages for yield formation of major staple crops such as wheat. In order to ensure stable agricultural production and satisfy demand of the increasing humanpopulation, it is crucial to know responses of major field crops to these abiotic stress factors to assess suitability of genotypes to specific environmental conditions. The aim of this study was to evaluate final yield formation parameters of five winter wheat genotypes cultivated in pots and exposed to two different levels of CO2 concentrations (400 ppm as ambient and 700 ppm as elevated CO2 concentrations) and two water treatments (well- watered control and drought-stressed plants). Theexperimental treatments were set up in growth chambers from the end of heading stage (BBCH 59)to the beginning of ripening stage (BBCH 71) to simulate the conditions under future climate. The results showed that elevated CO2 concentration led to: (1) mitigation of reduction in final yield formation parameters of drought-stressed plants compared to those of control, (2) enhanced results of drought-stressed treatments compared to those of drought-stressed treatments exposed to the ambient CO2 concentration. Pannonia NS was found out as the less responsive genotype to the exposition of CO2 concentration (no statistically significant differences among ambient and elevated CO2 concentrations in all yield formation parameters were identified). On contrary, harvest index of genotype Bohemia was identified as the most sensitive parameter in response to drought stress as well as to the atmospheric CO2 concentration.
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Comparing of observed and simulated field crop production in HERMES2Go model at Hněvčeves locality
Bohuslav, Jakub ; Kersebaum, Kurt Christian ; Madaras, M. ; Hlavinka, Petr ; Trnka, Miroslav ; Žalud, Zdeněk
The main objective of this study was calibration and testing of crop growth model \nHERMES2Go under long–term field experiment in Hněvčeves locality (coordinate 50°18´N, 15°43´E, \naltitude 265 m.a.s.l.). Observed data of yields and the other parameters like a weather data, soil \nparameters, management practice, phenology phases etc. monitored in last 38 years was used for model \ncalibration. Input parameters were available for 4 different fertilizer practices: i) control, ii) manure, iii) \nmineral fertilizer and iv) manure together with mineral fertilizer on each plot. Observed data are \navailable for yields of main and by–product and above ground biomass. The main grown crops were \nsugar beet, spring barley, winter wheat, silage maize, oat and alfalfa. Outputs of the model for main \nproduct are relatively accurate, but values of by–product requires additional calibration parameters \nsettings together with above–ground biomass.
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A variety of transpiration in the young spruce stands with different thinning management
Zavadilová, Ina ; Szatniewska, Justyna ; Vágner, Lukáš ; Krejza, Jan ; Pavelka, Marian
Managing the spruce forest growing beyond its favourable conditions is trading between water consumption and increasing biomass. We examined tree transpiration in four stands with different thinning intensities in a 40-year-old spruce forest in South Moravia. Tree transpiration was significantly higher under moderate and heavy intensity compared to low intensity and control plots. Tree transpiration differed also among trees of different sizes within the treatments and also between the treatments. The stem increment was visibly increasing with the intensity of treatment, particularly for suppressed trees. The findings show an ecological tree response two years after the thinning.
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