8 BULLETIN 45, HAWAII EXPERIMENT STATION. 
Whole v. cut seed. — Provided the young plant is furnished with a 
sufficient supply of nourishment by the seed piece until able to elab- 
orate its own food, there does not appear to be any difference whether 
the seed be entire tubers or cut pieces. It is true, however, that within 
limits the larger the seed piece the larger will be the resultant crop, 
but the smaller the percentage of marketable tubers. Whole tubers 
insure a good stand with greater freedom from disease. However, 
the growth of too many sprouts is to be discouraged, since too great 
a number of tubers will be set and comparatively few will be able to 
reach a satisfactory size. 
Greening the seed by exposure to light. — In order to hasten the 
germination or sprouting of seed, that is, to shorten the rest period, 
it is a common practice in Kula, Maui, to spread the tubers to be 
used as seed, as soon as they are dug, under a thin shade of bushes 
for several weeks or until they sprout. It is claimed that they will 
sprout in about half the ordinary dormant period. There is as yet 
no experimental evidence to support or controvert this statement of 
the farmers. This exposure, especialty to the high temperature of 
midday, probably serves to prevent any tendency of the seed to rot 
from the late blight fungus, but results in loss from other rots and 
from such insects as the tuber moth. The shortened period of dor- 
mancy, if a fact, is advantageous when potatoes are grown almost 
continuously and seed is difficult to obtain at certain seasons. 
Seed selection in relation to disease control. — Seed selection is not 
only of value in obtaining pure high-yielding strains within a va- 
riety, but it is of fundamental importance in preventing those diseases 
which are carried by the seed. Such supposedly nonparasitic but 
inherent diseases as curly dwarf, leaf roll, etc. ; the fungus diseases 
late blight, Fusarium wilt, rosette (Rhizoctonia), and those due to 
the scab fungi ; as well as certain insect pests, are carried by the seed. 
For avoiding these diseases any of the following well-known methods 
of selection are available: (1) Selection from the pile or lot, (2) field 
selection, (3) hill selection, and (4) regional selection and use of cer- 
tified seed. 
Selection of healthy tubers of uniform size and shape for seed from 
the mass is valuable in disease control, though not necessarily so 
in obtaining productive strains. As mentioned above, hill selection 
is of value both in disease control and in obtaining productive strains. 
Regional selection and the use of certified seed may well serve as 
means of starting seed plats in Hawaii. Seed should not be obtained 
from regions or from fields where noxious pests are known to be 
prevalent. 
Cutting seed. — In cutting potatoes for seed the tubers must be so 
cut that each seed piece or set shall have at least one strong eye. and 
it is desirable that each shall weigh about 1J ounces. First cut a 
thin slice from the stem end of the tuber and examine the flesh for 
