Coconut foliar decay (CFD) is a disease of
coconut (Cocos nucifera L.) associated with infection
by coconut foliar decay virus (CFDV), which is endemic
in Vanuatu, South Pacific. The local cultivar ‘Vanuatu
Tall’ (VTT) is the only cultivar that is fully tolerant to
CFD, whereas introduced cultivars and hybrids are
affected to different degrees. From 1967 to 2008 a
conventional breeding programme was conducted with
the aim of creating hybrid planting material combining
tolerance to CFD with improved copra yield and high
copra weight per nut. This objective was achieved by
crossing the progeny of selfed trees of ‘Rennell Island
Tall’ (RIT) cultivar, selected for their low susceptibility
to CFD in field screening tests, with VTT, improved by
mass selection and intercrossing. An improved
VTT 9 RIT hybrid was identified with a high degree
of tolerance to CFD (less than 1% of diseased trees after
11 years of exposure to high disease pressure). The
annual production of the improved VTT 9 RIT hybrid
ranged from 21.9 to 28.6 kg of copra per tree, depending
on the RIT parent, and was, on average, 34% higher than
that of ‘VTT Elite’ an advanced cultivar obtained after
four selection cycles of local VTT. However, the
production of the hybrid in Vanuatu involves constraints
such as frequent replanting and isolation of the seed
garden and CFD control for the RIT parents. The
importance of conducting research on the genetic
determinism and the mechanism of tolerance to CFD
for better control of the disease in the event that it
spreads outside Vanuatu is discussed.