Growth and nutritive value of cassava (Manihot esculenta Cranz.) are reduced when grown in elevated CO2

Two major problems facing the world are global climate change and food security. Globally, over 800 million people are undernourished and up to 2 billion people lack food security intermittently (FAO 2008). Projected changes in rainfall patterns, and an increase in the frequency and severity of drought, in many regions of the world will exacerbate this situation (Solomon et al. 2007; Funk et al. 2008; Liu et al. 2008). The hope is that the detrimental effects of climate change will be offset by higher plant growth rates as a result of rising atmospheric CO2, the so-called ‘CO2 fertlisation effect’ (Ziska & Bunce 2007; Jackson et al. 2008; Lobell & Field 2008). However, C3 plants acclimate to higher atmospheric CO2 to some extent, resulting in less growth enhancement than originally predicted (Morison & Lawlor 1999). Moreover, responses vary between species (Kimball 1983). It is important, therefore, that the growth of major staple crops be tested under different emissions scenarios so that informed adaptive responses can be made in a timely manner (Ainsworth et al. 2008). To achieve this goal, a basic