Experiments were conducted on rubber (Hevea brasiliensis
Mu¨ll. Arg.) with intact, fully expanded, 1–2 months old
leaves. Gas exchange was measured with a portable photosynthesis
system (LI-6400, LI-COR, Lincoln, Nebraska,
USA) equipped with a blue–red LED light source (LI-
6400-02B) and CO2 injection system (LI-6400-01).