Elevated CO2 reduces whole transpiration and substantially improves root production of cassava grown under water deficit

• Published in: Archiv für Acker- und Pflanzenbau und Bodenkunde Vol. 64; no. 12; pp. 1623 - 1634
• Main Authors: Cruz, Jailson L., LeCain, Daniel R., Alves, Alfredo A. C., Coelho Filho, Mauricio Antônio, Coelho, Eugênio Ferreira
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 15.10.2018; Taylor & Francis Ltd
• Subjects: Carbon dioxide; Cassava; Climate change; Drought; Dry matter; harvest index; Hunger; Moisture content; photosynthesis; Physiological effects; Plant growth; Precipitation; Rainfall; Roots; Soil water; Transpiration; Water deficit; Water use; Water use efficiency
• ISSN: 0365-0340; 1476-3567
• DOI: 10.1080/03650340.2018.1446523

We evaluated the possibility of elevated CO 2 concentration ([CO 2 ]) to reduce the negative effect of drought on growth and physiological parameters of cassava (Manihot esculenta Crantz). Plants were grown with 390 ppm or 750 ppm of CO 2 , under well-watered or under water deficit conditions. The study was conducted in a climate-controlled greenhouse using 14 L pots, for 100 days. For any value of fraction of transpirable soil water (FTSW) the carbon assimilation was always higher for plants grown under elevated [CO 2 ]. Still, elevated [CO 2 ] reduced the negative effect of drought on transpiration, water use efficiency, all growth measures and harvest index. Elevated [CO 2 ] increased the dry matter of tuber roots (DMTR) of well-watered plants by 17.4%. The DMTR of plants grown under water deficit were 124.4 g and 58.9 g, respectively, for plants under elevated and ambient CO 2 , an increase of 112%. Thus, the CO 2 effect was relatively stronger to the production of tuberous roots when cassava were subjected to water-deficit. Our results suggest that cassava tuber production might be resilient to changes in precipitation that will accompany higher atmospheric CO 2 and reinforce cassava as a specie that can significantly contribute to mitigate hunger in a changing climate environment.