PAPAYA CULTUIiE IN HAWAII 
27 
life of the seedlings, and has been observed in papaya plants propa- 
gated from cuttings, grafts, and seeds in Hawaii. It appears as a 
natural old-age condition of an herbaceous, short-lived plant. The 
cuttings and grafted plants possibly carry and transmit the age limit 
as they do other varietal and specific characters of the original seed- 
lings. Wester (23, p. 57-59), who made rather extensive experiments 
in grafting tropical plants in the 
Philippines, briefly described cleft 
and side grafts successfully made 
with the papaya, but he did not 
discuss the practicability of vegeta- 
tive propagation. 
Grafting experiments with the 
papaya were continued for about 
four years at the station. The 
plants used varied from small-pot 
size to field-grown plants of about 6 
months of age. Where pot-grown 
plants were grafted, young seedlings 
about 2 inches high were trans- 
planted from the flat to 3!/2-inch 
pots of rich, sterilized soil. After 
a day or two in the slat propaga- 
tion house for partial shelter from 
the sun, they were put on benches 
in the open nursery in the full 
sunlight to enable them to make 
rapid and stocky growth. They 
were kept far enough apart to avoid 
spindling growth. Grown in this 
way, they required about 40 days 
to reach suitable size for graft- 
ing. At this age the stems of the 
young seedlings were easily grafted. 
The methods of grafting tried were 
the cleft-graft and the whipgraft. 
In the cleft-graft method the seed- 
ling is cut squarely off with a sharp 
knife at a convenient point above 
ground and where it is desired to 
insert the scion. The stump is then 
split clown about 1 to iy 2 inches. 
The scion is cut to a long wedge at 
the basal end and then pushed 
down firmly into the cleft of the 
stock; for further security the union 
is bound with raffia. The leaf blades 
of the larger leaves are clipped off to retard evaporation. This form 
of union is used only where the seedling and the scion are small and 
have not formed the hollow cavity which develops in larger papaya 
stems. Uniformity in size of stock and scion is not so important 
in grafting small plants as in the larger ones. However, the scion 
should not be larger than the stock. 
Figure 27. — The rooting of a cutting 
is slow and the newly formed roots 
are very fibrous. This method of 
propagation is unsatisfactory for com- 
mercial fruit production 
