Viability of Seeds — Akamine 
37 
EXPERIMENTAL PROCEDURE 
The seeds of the seven forest tree species 
used in these studies were harvested and col- 
lected from the various forest reserves 
throughout the Territory by the foresters of 
the Territorial Board of Commissioners of 
Agriculture and Forestry. The viability studies 
were conducted by the Department of Plant 
Physiology at the University of Hawaii Agri- 
cultural Experiment Station. Freshly harvested 
and cured seeds were used. Species and their 
storage periods are listed in Table 1, 
Because of the dijSiculty encountered in 
most of the species in separating normal em- 
bryonated seed from empty seed by external 
appearance the ”per cent normal seed” for 
each species was determined from internal 
examination of lots of known numbers of 
seeds obtained at random (Table 1). Germina- 
tion tests were conducted on lots of seed 
counted out at random, and the percentage of 
germination was based on the "per cent 
normal seed.” 
Seeds were stored at relative humidities of 
approximately 30, 45, 60, 75, and 90 per cent 
at temperatures of 45°, 59°, and 70°-80° F. 
(room temperature) The required humidities 
were maintained with solutions of sulphuric 
acid of various concentrations (Akamine, 
1943 ) in large desiccators. Some seeds of each 
species were stored in airtight containers 
without humidity control at each temperature, 
and control lots of seeds stored in the open 
were also included under each temperature. 
At intervals during the storage period, the 
specific gravity of the sulphuric acid solutions 
was determined with a hydrometer, and any 
divergence from the required specific gravity 
was corrected by the addition of water or con- 
centrated sulphuric acid. 
At the time of storage, an initial germina- 
tion test was conducted on the seeds of each 
species. Thereafter, germination tests were 
^The cold storage facilities of the United States 
Department of Agriculture Bureau of Entomology and 
Plant Quarantine at Honolulu, T. H., were used during 
the early stages of this study. 
conducted at intervals, once in approximately 
1 to 2 months, at the beginning of the storage 
period, and once in approximately 6 months, 
during the latter part. Data on the germina- 
tion test period, germination condition, 
number of replications, and number of seeds 
per replication for seeds of each species are 
shown in Table 1. In all cases, tap water was 
used in the substratum. The sandalwood 
seed, with its seedcoat removed by hand, 
was treated with a fungicide ("Thiosan”). 
The seedcoat was removed to hasten germi- 
nation, and the fungicide was applied to pre- 
vent the contamination of the germination 
medium by mold organisms. Before testing 
them, the seeds of mamani were mechanically 
scarified for 2 to 3 minutes in a shaking 
machine (Akamine, 1942), using an equal 
amount of black sand and seed. The black 
sand was used to abrade the seedcoat, which 
in this seed is impervious to water and hence 
requires scarification in order for the seed to 
germinate. The few hard unswollen seeds re- 
maining at the end of the germination test 
were nicked on the seedcoat with a knife and 
left for an additional period to germinate. In 
all cases, all sound ungerminated seeds left 
at the end of the test were considered viable 
and included in calculation of the germina- 
tion percentage. Because of their enormous 
size, the seeds of Norfolk Island pine were 
germinated in a Minnesota seed germinator 
at room temperature instead of in the petri 
dish. The criterion of germination was the 
emergence of normal primary roots and 
shoots. 
EXPERIMENTAL RESULTS 
For the sake of brevity, the voluminous 
germination data on the stored seeds have 
been omitted in this paper, and, in their place, 
graphs^ constructed from these data are pre- 
sented in Figures 1 to 7. To present the trend 
of the germination more readily, the curves 
for these graphs were drawn from points ob- 
^The author is indebted to Herbert Sakamoto for the 
construction of the graphs. 
