Bwa-yo - Société Audubon Haiti

18 Bwa Pie
oftraditional propagation methods in the Lascahobas area, sown seed accounts for only
5% of the C. arborescens tallied (Campbell, 1994). More than two-thirds of the trees
were volunteer, with an additional 16% that were transplanted volunteers.
An attempt was made to graft and bud the species in 1988 by the Double Harvest
nursery, but all attempts failed with the split, inverted-T bud and cleft methods. No
knowledge of vegetative methods has been reported in Haiti.
Seed Research: The hard seed coat inhibits germination. Scarification by nicking the
small seed results in a 4-fold increase in total germination. However, this is not costeffective
for bulk seed and most nurseries compensate for low and irregular germination
by sowing extra quantities of seed for transplants. An experiment designed to test
scarification procedures showed that immersion in 80° C water, followed by a 24-hour
soak, significantly reduced seed germination, whereas soaking in cold water for 24
hours had no effect. Furthermore, there was a poor correlation between laboratory germination
tests and nursery emergence. No differences in germination were detected
when ripe seed was harvested from the same orchard trees at 3-week intervals during
the peak fruiting season (May to July).
Planting Stock Quality: Various methods to establish C. arborescens in the field have
been tested for their effect on survival and growth (Dupuis, 1986a; Reid, 1991). Direct
seeding of the species has consistently failed in the field and can be recommended only
ifseed is plentiful. Container types and potting mixes showed no effects on a fertile site
near Port-au-Prince. However, seedlings raised in a polythene sack survived better on a
drier, less fertile site than did the smaller-containerized seedlings raised in the
Rootrainer or Winstrip. This difference was accounted for by the larger soil volume of
the sack and a more well-developed seedling root system.
Figure 2.9 Deformed leaves of a C. arborescens nursery seedl ing probably are caused
by an aphid-borne virus.