Performance of two Pinus patula hybrids in southern Africa

Abstract

Two Pinus patula hybrids, P. greggii × P. patula and P. patula × P. tecunumanii, were planted across a number of sites in southern Africa. The growth and survival for each species/taxon was assessed at either 5 or 8 years of age at each site and compared to the respective parental species. Pinus greggii, as a pure species, has greater drought tolerance and is better adapted to harsher sites than P. patula. At 8 years the P. greggii × P. patula hybrid had similar survival and was more productive than P. patula at the two sites where it was tested. Furthermore, the performance of the hybrid was better than pure species on the site with average poorer growth suggesting that this hybrid could be planted on poorer, more marginal sites not well suited to P. patula. Pinus tecunumanii is a productive species with good tolerance to the pitch canker fungus (PCF). Previous work has shown that the P. patula × P. tecunumanii hybrid is more tolerant to PCF after field inoculations. The latter hybrid was assessed at 5 years on three sites and compared to both parent species. The hybrid had similar survival and was more productive than both parent species. Large variation in performance between individual P. patula × P. tecunumanii families suggests that comprehensive testing and selection should be conducted in tandem with any operational deployment of this hybrid.