Abstract:
Plantation forestry in Colombia is based mainly on non-native species of Pinus and
Eucalyptus. Since 2008, a disease with symptoms similar to those of Dothistroma needle
blight (DNB) have been found affecting large areas planted to Pinus spp. The aim of this
study was to identify the causal pathogen as well as to document the levels of disease
incidence and severity. Isolates from each of three forestry zones, collected from
different host species, were compared based on rDNA sequence of the ITS regions.
These were conclusively identified as Dothistroma septosporum, one of two Dothistroma
spp. known to cause DNB. Susceptibility was greatest on low elevation P. tecunumanii
followed by P. kesiya and P. oocarpa. Pinus maximinoi and high elevation P. tecunumanii showed tolerance to D. septosporum. The disease incidence in the different
zones varied significantly with the Northern zone being the most severely affected. This
constitutes the first report of disease distribution and susceptibility of hosts, as well as the
first consideration of the relative importance of D. septosporum in Colombia.
