Beschreibung:
<jats:p>I considered the possibility that changes in fruit photosynthesis obscure the occurrence of the climacteric rise in respiration in tomato fruits attached to the plant. Internal CO<jats:sub>2</jats:sub> and ethylene concentrations in tomatoes (<jats:italic>Lycopersicon esculentum</jats:italic> Mill. cv. OH 7814) were analyzed after direct sampling through polyethylene tubes implanted in the external pericarp. Fruits which were shaded with aluminium foil contained up to 60 ml 1<jats:sup>−1</jats:sup> CO<jats:sub>2</jats:sub>, until the internal ethylene concentration exceeded 1 μl l<jats:sup>−1</jats:sup>, when CO<jats:sub>2</jats:sub> concentration declined to below 40 ml l<jats:sup>−1</jats:sup>; the CO<jats:sub>2</jats:sub> concentration in fruits exposed to light only occasionally exceeded 40 ml 1<jats:sup>−1</jats:sup>. The internal CO<jats:sub>2</jats:sub> concentration of detached fruits first declined and then increased along with ethylene concentration, as expected for the climacteric. Detached green fruits under continuous low photosynthetic photon flux density (100 μmol m<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup>) contained almost no internal CO<jats:sub>2</jats:sub> and produced no CO<jats:sub>2</jats:sub>. Changes in photosynthesis and an associated CO<jats:sub>2</jats:sub>‐generating system in green fruits are thought to obscure the climacteric rise in tomato fruits developing on the plant.</jats:p>