Bwa-yo - Société Audubon Haiti

Figure 4.10 ... and 4 years later, showing excellent
growth of C. longissima.
Chenn 37
dates and established in a series of
progeny trials and seedling seed
orchards throughout Haiti. All
progeny tests and orchards are comprised
of open-pollinated stock.
No maternal effects have been
detected for 3-year survival and
height growth. Within-family variation
is as large as inter-family differences.
For example, at the
Laborde progeny trial near Cayes, a
23% difference between the firstand
last-ranked families in height
growth (4.7 m v. 3.8 m) at 3 years
was not significant. Survival likewise
was the same across families,
ranging from 96-100%. This finding
directs further breeding strategies
towards selection of individuals
that can be vegetatively propagated
and installed in second-generation
orchards.
The orchard of 55 half-sib families
at Roche Blanche probably
contains the broadest genetic base
of C. longissima in its native range.
The orchard began yielding seed in
the second year. The photo in Fig. 4.4, taken at this orchard, shows the seasonal insect
defoliation that often attacks the species when it is under drought stress. But it also
underscores the worth of an investment to conserve a genetic diversity that can better
cope with changes in pests and growing conditions of such an economically important
tree species. Several periodic studies on the intensity of defoliation exhibited no family
differences. However, the effect of annual attacks may be causing growth differences
among families, with the top families showing superior vigor and an advantage of
40-50% in height growth over 5 years. The 2 largest individuals in the orchard come
from the same mother tree, a positive indication that improvement can be made in Haiti.