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Effect of nutrients deficiencies on root architecture and growth of winter wheat
Rattanapichai, W. ; Klem, Karel
The study of the effects of N, P, K deficiencies on root architecture and growth was tested in phenotyping platform with winter wheat (Bohemia variety). The experiment was arranged with 4 treatments: Complete nutrient, Without N, Without P and Without K. The root were grown on the surface of vertically fixed black filter paper sheets (30x60cm), covered from both sides by black plastic sheets (PVC-P). The system was setup with a micro-irrigation channel in the top of sheets to ensure circulation of hydroponic medium as hydroponic system. Eighteen days after transplanting, we took the root images by the standard RGB digital camera. To evaluate the root architecture parameters the "SmartRoot" software was used. The results showed that nutrient deficiency had effect on root architecture of winter wheat. N deficiency increase in total seminal root and lateral root length and root/shoot ratio, while P deficiency resulted in increase of mean root diameter, total root area when compared to the control. N deficiency also decreased root and shoot dry weight and total leaf area. However, nutrient deficiency slightly decreased lateral density. There was a slight effect of K deficiency on root architecture when compared to the complete nutrient application. The increasing of leaf dry weight was related with the increased of root dry weight.
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Monitoring of water use, druought and yield impacts of winter wheat using imaginery from satellites
Jurečka, František ; Anderson, M. ; Hlavinka, Petr ; Semerádová, Daniela ; Trnka, Miroslav ; Hain, C. ; Gao, F. ; Yang, Y. ; Žalud, Zdeněk
Remote sensing can be very useful tool for drought monitoring, providing valuable information about yield-limiting moisture conditions and crop response under current climate conditions. In this study the Atmosphere-land Exchange Inverse (ALEXI) model was used. The ALEXI model uses the morning surface temperature (LST) rise and provides information on the surface moisture status. In this paper correlations between yields and satellite indicators of crop water use or evapotranspiration (ET) were studied for the period 2002-2014. Correlations were studied for winter wheat at district scale in Vysocina, Jihomoravsky and Olomoucky regions since winter wheat is one of the traditional and most important crops grown in these regions. The Evaporative Stress Index (ESI) was used for these correlations as an ET-based index. Time series of Pearson correlation coefficient (r) computed between ESI and winter wheat yields at district scale were analysed. Strongest correlations are associated with districts within the Southern Moravian lowlands in Jihomoravsky and Olomoucky region, where frequency of occurrence of severe drought was highest over the period of record. Severe drought resulted in significant yield impacts, particularly in years 2003 and 2012. Correlations tend to be lower over the highlands districts of Vysocina and surroundings. In these districts, yields are more temperature than moisture limited and were more stable over the period of record.
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Effect of temeperature stress and water shortage on thousand grain weight of selected winter wheat varietes
Hlaváčová, Marcela ; Pohanková, Eva ; Klem, Karel ; Trnka, Miroslav
The aim of the presented study was to assess the effect of high temperatures and water shortage during anthesis on thousand grain weight (TGW) of two winter wheat varieties (Tobak and Pannonia). In addition, numbers of grains per spike were also assessed. The six growth chambers were used to simulate heat stress conditions within following gradient of temperature maxima: 26 degrees C (control chamber), 29, 32, 35, 38 and 41 degrees C. The relative humidity (RH) course and photosynthetically active radiation (PAR) intensity were controlled via protocols. Additionally, drought stressed (dry) and well-watered (wet) treatments were established within each growth chamber. The plants were removed from the growth chambers after 14 days and they were left until a full maturity, exposed to actual weather conditions. The TGW at 14% moisture were evaluated for particular treatments within both winter wheat varieties. TGW was generally more affected by high temperatures under drought stress than in well-watered conditions. The results revealed that Pannonia TGW was much more affected by the water deficiency in combination with high temperature (particularly 38 and 41 degrees C) than Tobak TGW.
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