Abstract:
Field establishment of South Africa’s most important commercial pine species, Pinus patula, is severely hampered
by the pitch canker fungus, Fusarium circinatum. Importantly, hybrids between P. patula and other pine species
tolerant to the pitch canker fungus, such as P. tecunumanii and P. oocarpa, have been identified as an alternative
planting stock. In this study, variation in tree volume and dynamic modulus of elasticity (MOEdym) of the P. patula
× P. tecunumanii (low- and high-elevation [LE and HE] ecotypes) hybrid was compared with the P. elliottii ×
P. caribaea hybrid, and the pure species P. tecunumanii (LE) and P. patula. The MOEdym was assessed using the
Fakkop TreeSonic microsecond instrument across three sites. The results of the study showed that P. patula ×
P. tecunumanii LE performed significantly better than P. patula × P. tecunumanii HE for volume and MOEdym, which
in turn was significantly better than P. patula. The MOEdym and tree growth decreased with an increase in elevation.
There was significant taxon × site interaction for volume and MOEdym. The results of these trials suggested that
P. patula × P. tecunumanii LE is a suitable alternative to P. patula in the Sabie region of Mpumalanga in South Africa
on frost-free sites, in terms of the traits that were assessed.
