2 - 4 %
||Kirschbaum MUF (2011) Does enhanced photosynthesis enhance growth? Lessons learned from CO2 enrichment studies. Plant Physiol 155: 117–24 p.117 left column top paragraph & right column top paragraphPubMed ID21088226
||Long SP, Zhu XG, Naidu SL, Ort DR (2006) Can improvement in photosynthesis increase crop yields? Plant Cell Environ 29: 315–330 & Zhu XG, Long SP, Ort DR (2010) Improving photosynthetic efficiency for greater yield. Annu Rev Plant Biol 61: 235–261PubMed ID17080588, 20192734
||"Plants typically convert only 2% to 4% of the available
energy in radiation into new plant growth. This
low efficiency has provided an impetus for trying to
genetically manipulate plants in order to achieve
greater efficiencies...Photosynthesis is a relatively inefficient process, with only a maximum of 8% to 10% of the energy in sunlight being converted to the chemical energy in reduced sugars (BNID 110844, primary sources). Further considering carbon losses from autotrophic respiration and limitations by other factors such as water and nutrient limitations, realized conversion efficiencies are typically just 2% to 4% of the energy received in sunlight (primary sources)."