CIFOR–ICRAF publishes over 750 publications every year on agroforestry, forests and climate change, landscape restoration, rights, forest policy and much more – in multiple languages.

CIFOR–ICRAF addresses local challenges and opportunities while providing solutions to global problems for forests, landscapes, people and the planet.

We deliver actionable evidence and solutions to transform how land is used and how food is produced: conserving and restoring ecosystems, responding to the global climate, malnutrition, biodiversity and desertification crises. In short, improving people’s lives.

The influence of R:FR ratio on the growth, photosynthesis and rooting ability of Terminalia spinosa Engl. and Triplochiton scleroxylon K. Schum.

Export citation

Stockplants of the tropical hardwoods Terminalia spinosa Engl and Triplochiton scleroxylon K. Schum were grown in a controlled environment under red:far-red (R:FR) ratios ranging from 0.5-3.1. In both species rates of shoot height increment were higher (P < 0.05) under the low R:FR ratios as a result of increased internode elongation. In Terminalia spinosa specific leaf area (SLA) was also significantly higher under lower R:FR ratios values ranging from 175 to 210 cm2 g-1 in the 3.1 and 0.9 treatments respectively. No effect of R:FR ratio on SLA was recorded in Triplochiton scleroxylon. Pre-severance photo-synthetic rate stomatal conductance and water-use efficiency were increased under the higher R:FR ratios in Terminalia spinosa rates of photosynthesis ranging between 2.68-4.59 μmol m-2 s-1 in the 0.5 and 3.1 R:FR treatments respectively. Gas exchange rates of Triplochiton scleroxylon were unaffected by R:FR treatment. These contrasting responses to variation in R:FR ratio were associated with differences in rooting ability. In Terminalia spinosa significantly higher percentage rooting was recorded in the cuttings from the 3.1 R:FR treatment than from 0.5 with values of 93.7% and 77.5% recorded respectively. R:FR ratio also affected rooting percentages of Triplochiton scleroxylon but in this case higher rooting percentages were recorded in the lower R:FR ratios values ranging from 31.1–54.1% in the 3.0 and 0.5 R.FR treatments respectively. This difference in rooting response is attributed to the contrasting effects of R:FR ratio on the leaf and stem morphology of the two species. The implications of these results for stockplant management are discussed.

Related publications