Washa, W. B. A.; Nyomora, Agnes M. S.
Description:
Abstract: A study was conducted to investigate the effect of moisture and seed
treatment on the in-situ and ex-situ regeneration of Dalbergia melanoxylon in Pugu
forest reserve. Seed germination experiments was conducted for three months
between November and December 2005 in the nursery Botany Department of the
University of Dare s Salaam while seedling growth rate measurements were
conducted for 12 months between January and December 2006 in the Pugu forest
reserve. A total of 2 kg of D. melanoxy seeds collected from Pugu forest reserve and
some from Tanzania Tree Seed Agency (TTSA) were used for seed germination
experiments. A total of 25 seedlings approximately 2 years old were randomly
chosen from Pugu forest reserve for seedling growth rate experiments. A split plot
experimental design was used for seed germination in the nursery where soaked
and non-soaked seeds stood for main plot and different moisture level treatments
stood for subplot. Parameters recorded were germination dates, germination
percentages, seedling increase in height and seedling increase in girth. Manual
computation of data was accomplished according to Zar, 1988 where LSD was used
for mean separation to determine statistical differences between treatment means.
Tables and Figures were used to facilitate presentation and discussion of results.
Data analysis led to the conclusion that, a moderate ex-situ moisture level of 200ml
in a 1L pot per day effectively promoted seed germination up to 21% in seeds
previously soaked in water for 6 hours compared to high moisture treatment of
300ml in a 1L pot per day which effected seed germination only by 11.6%.. The
maximum in-situ growth rate was concluded to be 0.01 cm/month. The study
revealed that seeds and young seedlings of D. melanoxylon are vulnerable to high
moisture level while older trees are water and light demanding. It was
recommended that future researches should endeavour to increase seed viability by
harvesting them immediately from their maturity and storage in sealed containers,
conducting tissue culture to manipulate seedlings and hybridization experiments
with related species to reduce growth period.