Riesgos de mercado a) Riesgos de tasa de cambio

In this study, it has been shown that the presence or absence of a ponded water layer in irrigated rice fields affects the thermal environment at meristem level. Under non-flooded conditions, the plant’s meristem is subjected to a larger temperature amplitude compared to continuously flooded conditions. Minimum meristem temperature was always lower under non-flooded conditions, whereupon the difference in minimum meristem temperature between irrigation treatments increased with decreasing air temperature. With increasing minimum meristem temperature, a linear increase of stomatal conductance, assimilation rate, leaf area development and spikelet fertility was found in the observed temperature range. Since the number of spikelets per panicle was highly correlated with leaf area per tiller, which increased with increasing meristem temperature, the number of spikelets per panicle was also affected by meristem temperature. Therefore, lower meristem temperature under non-flooded condition led to lower assimilation rates, less leaf area, lower spikelet fertility, less spikelets per panicle, and thus yield reductions in comparison to continuously flooded fields. This effect was larger during the cold- dry-season, when night temperatures are relatively low, whereas during the hot-wet-season, no yield reductions have been observed under non-flooded conditions. In areas or periods where night temperatures below 20°C occur, the combined effects of changes in meristem temperature should be considered when water-saving measures are to be applied. Thus, since rice is a thermophilic crop, it is extremely important to pay attention to temperature critical phases in the yield building process and to not compromise yield through the water-saving method used. Since different water saving irrigation technologies exist, it would be advisable to adjust the respective method to the respective environmental conditions and within this best also to the variety used. This would either imply intensive phenotyping of a large number of rice genotypes or developing a crop simulation model sensitive enough to simulate the effects of different irrigation methods on the yield building processes and their temperature critical phases.

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Declaration of Originality

Hereby I declare that this doctoral thesis is independently written by myself. In addition, I confirm that no other sources than those specified in the thesis have been used. I assure that this thesis, in the current or similar format, has not been submitted to any other institution in order to obtain a Ph.D. or any other academic degree.

Ich erkläre hiermit, dass ich diese Dissertation selbständig angefertigt habe. Es wurden nur die im Literaturverzeichnis aufgeführten Hilfsmittel benutzt und fremdes Gedankengut als solches kenntlich gemacht. Ich versichere, dass ich diese Arbeit in gleicher oder ähnlicher Form noch keiner anderen Institution zur Prüfung vorgelegt habe.

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Sabine Stürz

Dürnauer Weg 27 70599 Stuttgart 0711-45923603 [email protected] since 02/2008 04/2005 – 12/2007 10/2002 – 03/2005 10/1999 – 03/2002 06/1998 Date of birth December 6, 1978 Work experience Scientific staff

University of Hohenheim, Stuttgart, Germany

Institute of Plant Production and Agroecology in the Tropics and Subtropics PhD student in the frame of the RISOCAS project – Developing Rice and Sorghum Crop adaptation Strategies to cope with Climate Change

Teaching in the study courses “Nachwachsende Rohstoffe und Bioenergie (Bsc)“ and „Agritropics (Msc)“

Supervision of Bachelor and Master Students

Education

University of Bonn, Germany Diplomstudiengang Biologie

Major subjects: Plant physiology, Microbiology, Plant nutrition in the Tropics and Subtropics

Title of qualification: Diplombiologin

University of Würzburg, Germany Diplomstudiengang Biologie

Title of qualification: Vordiplom Biologie

University of Würzburg, Germany Magisterstudiengang Sonderpädagogik

School leaving certificate

93 Hohenheim, January 12, 2014.

Sabine Stürz

Conference oral presentations

Conference poster presentations

1. Stuerz, S., Sow, A. , Asch, F. 2012. Impact of Irrigation System on

Microclimatic Parameters and Gas Exchange in Lowland Rice. In: Thielkes, E. (Ed.) Tropentag 2012 – Resilience of Agricultural Systems against Crises. Göttingen, September 19-21, Book of Abstracts, p. 112, Cuvillier Verlag, Göttingen.

2. Stuerz, S., Sow, A., Asch, F. 2011. Impact of climatic conditions on rice yield under water-saving irrigation in the Sahel. In: Becker, M. (Ed.) Tropentag 2011 – Development on the Margin. Bonn, October 5-7, Book of Abstracts, p. 270, Cuvillier Verlag, Göttingen.

3. Stuerz, S., Sow, A., Muller, B., Manneh, B., Asch, F., 2011. Effect of

temperature on relative yield and duration of lowland rice under water-saving irrigation. International conference on crop improvement, ideotyping and modeling for African cropping systems under climate change (CIMAC), February 7-9, 2011, Hohenheim, Germany.

4. Stuerz, S., Sow, A., Muller, B., Manneh, B., Asch, F., 2010. Climatic effects on genotype-specific transpirational water use in irrigated rice. International Rice Congress 2010, November 8-12, 2010, Hanoi, Vietnam.

1. Stuerz, S., Asch, F., Sow, A., Muller, B., Manneh, B. 2010. Intra-annual genotypic patterns of growth and water use of irrigated rice in the Sahel. In: Thielkes, E. (Ed.) Tropentag 2010 – World food system - A contribution from Europe. Zurich, September 14-16, Book of Abstracts, p. 376, Cuillier Verlag, Göttingen.

2. Hartmann, J., Stuerz, S., Manneh, B., Sow, A., Asch, F. 2010. Response of transpiration of lowland rice varieties to water-saving irrigation. In: Thielkes, E. (Ed.) Tropentag 2010 – World food system - A contribution from Europe. Zurich, September 14-16, Book of Abstracts, p. 370, Cuillier Verlag, Göttingen. 3. Stuerz, S., Asch, F., Sow, A., Muller, B., Manneh, B., Dingkuhn, M., 2010.

Phenological responses of irrigated rice in the Sahel. Africa Rice Congress 2010, Innovations and Partnerships to realize Africa's Rice Potential, March 22- 26, 2010, Bamako, Mali.

4. Stuerz, S., Sow, A., Schlegel, I., Manneh, B., Asch, F. 2009. Annual variation of water use and yield of irrigated rice in the Sahel. In: Thielkes, E. (Ed.)

Tropentag 2009 – Biophysical and socio-economic frame conditions for the sustainable management of natural resources. Hamburg, October 6-8, Book of Abstracts, p. 158, Cuvillier Verlag, Göttingen.

5. Stuerz, S., Schlegel, I., Sow, A., Asch, F. 2008. Physiological Responses of Lowland Rice Cultivars to the Saturated Soil Culture System. In: Thielkes, E. (Ed.) Tropentag 2008 – Competition for Resources in a Changing World: New Drive for Rural Development. Hohenheim, October 7-9, Book of Abstracts, p. 488, Cuvillier Verlag, Göttingen.

6. Stuerz, S., Asch, F., Becker, M. 2007. Field validation of a quick screening method for iron toxicity in lowland rice. In: Thielkes, E. (Ed.) Tropentag 2007 – Utilisation of Diversity in Land Use Systems: Sustainable and Organic

Approaches to Meet Human Needs. Witzenhausen, October 9-11, Book of Abstracts, p. 456, Cuvillier Verlag, Göttingen.

In document Estados Financieros Consolidados. Vanti S.A. ESP (página 32-36)