PAPAYA CULTURE IN HAWAII 
29 
healing of the graft union. These tend to weaken the trunk and 
may admit destructive fungi, which may prove to be fatal to the 
plant. Some successful unions were made with whipgrafts. (Fig. 
29.) Grafted plants came into fruit from four to six months after 
the unions were made. During the remainder of their existence 
most of the grafts had 
periods of slow growth 
which were indicated by 
constricted sections of 
trunk with nodes more 
closely packed. Growth 
was not vigorous, and fruit 
production was not abun- 
dant. By January, 1924, 
all the grafted plants had 
died from lack of vigor. 
The results of the experi- 
ment indicated the im- 
practicability of trying to 
change the sex of papaya 
plants by means of graft- 
ing them in the field. 
CULTURE 
NATURAL REQUIREMENTS 
In Hawaii the papaya 
thrives best at altitudes 
below 1,200 feet, luxuriat- 
ing and producing its best 
fruit in the warmest lo- 
calities (P, p. 7-8). The 
effect of the lack of heat 
in the cool season is shown 
by the slow growth and 
the setting of less fruit, 
and also by a retardation 
of the processes of growth 
and ripening of the fruit. 
Fruit produced at high 
altitudes or that maturing 
during cool weather fails 
to reach its normal color 
and the flesh also is pale and of insipid flavor. Papaya plants when 
grown in warm and somewhat sheltered sections often appear to be 
more or less dwarfed in form and begin fruiting at an early age. 
(Fig. 30.) The plant, however, eventually reaches normal height. 
In regard to rainfall and moisture requirements, the plant is able to 
adapt itself to a wide range of conditions, and when well established 
suffers much less from a shortage of moisture than do many other 
kinds of fruit trees. The plant makes beneficial use of large amounts 
of water when it is supplied. Light, misty rain, blown continuously, 
or nearly so, by trade winds for several days, as occasionally takes 
Figure 29. — Grafting the papaya is not difficult, 
but it is generally unsatisfactory 
