Propagating Osyris lanceolata (African sandalwood) through air layering: its potential and limitation in Tanzania

Abstract

Propagation of African sandalwood (Osyris lanceolata) by air layering (marcotting) was investigated at Sao Hill, Tanzania, aiming at providing an alternative propagation technique to the use of seeds or cuttings that germinate or root poorly. Air layers were initiated on the young shoots (1 – 2 years old) of mature O. lanceolata trees growing at Sao Hill catchment Forest. After root initiation, which took 8 weeks, they were detached from the parents, potted in polyethylene tubes and reared at the nursery for a further three months. The factors assessed in this experiment were the effect of time at which air layers were initiated (i.e. February, June, September and December); and the influence of IBA as rooting promoter at three concentrations (50, 100 and 150 ppm). From the data collected it was observed that rooting success of up to 80% can be achieved from air layers, making this propagation technique a viable alternative to seedlings or cutting propagation. Rooting success was influenced by both the season and application of rooting hormone with optimal rooting being achieved during June and September with the addition of IBA at a rate of 50 ppm. The significance increase in rootability of air layers during June and September may be linked to the advantage of the dry season in Tanzania where reduction of plant development activities such as budding, leafing and flowering in the dormant dry season might have reduced resource competition and thus promoting the observed rooting.

Keywords: Osyris lanceolata, air layering, growing season, IBA application, rooting success, nursery survival

Southern African Forestry Journal Vol. 207 2006: 7-13