Abstract:
To meet the increasing demand for Cape St. Paul Wilt Disease (CSPWD)
tolerant coconut seedlings, this research was carried out to develop
interventions for improving seed nut germination and vigour, seedling quality
and vigour and Sri Lanka Green Dwarf (SGD) fruit characteristics. Seven (7)
different experiments were carried out to assess pre-nursery practices, seedling
spacing and fertilizer application, ablation and fruit thinning towards addressing
deficiencies in coconut nursery and tree management practices. Fully burying
Sri Lanka Green Dwarf crossed Vanuatu Tall (SGD x VTI) coconut hybrid
seed nut in decomposed sawdust at pre-nursery stage improved germination
rate, speed of germination and germination index respectively by 33%, 30%
and 98% relative to the control. A treatment combination of 60-cm triangular
spacing and fertilizer application of 47.3:96.6:126.0:28.4 g seedling·1
N:P20S:K20:MgO produced good quality SGD x VTI coconut hybrid
seedlings with averagely 34% higher vigour, 12% bigger collar girth, 11 %
wider canopy diameter and 5% increase in height relative to the control.
Thinning ofSGD coconut variety to 10 fruits per bunch increased crude protein
and Vitamin C contents of fresh fruits by 31 % and 42% respectively; and
average fresh fruit weight by 32% and its components: husk, shell, kernel and
water averagely by 42%, 61 %, 42% and 65% respectively. Findings of prenursery
studies are recommended for dissemination to appropriate entities to
improve seed nut germination rate and increase supply ofSGD x VTI coconut
hybrid seedlings to fanners. Further research is recommended for assessing
field perfonnance of SGD x VTI coconut hybrid seedlings as affected by
potassium nitrate soaking treatment, planting depth or nut size.
