PAPAYA rri.TCKK l.\ HAWAII 
25 
the parent plant so as to leave the natural enlargement on the basal 
end of the cutting. At this point the tissue is fairly hard and will 
tend to root without decaying if the surface is smoothed with a sharp 
knife. The inner tissues of the papaya plant, if exposed, are excep- 
tionally favorable for the entry, rapid development, and spread of 
destructive fungi. Cuttings, particularly when sections of branches 
are used, should be dried for a day or two to heal the cut surfaces. 
The exposed cut surface of the stems of such cuttings above ground 
should be capped with a small amount of grafting wax. All large 
leaf blades should 
be removed, leaving 
only petioles several 
inches in length. 
This prevents undue 
transpiration from 
taking place and 
thus keeps the cut- 
tings from wilting. 
The petioles will 
soon drop and leave 
leaf scars which will 
heal before fungi 
have time to enter 
them. 
At the station the 
cuttings were rooted 
in different medi- 
ums, such as coral, 
beach, and black vol- 
canic sand, and well- 
decomposed lava 
soils. Trials in these 
soils weremade in the 
propagating house, 
in open benches sev- 
eral feet above 
ground in the nurs- 
ery, and in the field, 
Trials in the field 
were made in both 
decomposing tufa 
soils and basaltic 
soils. All the trials 
were made without 
bottom heat. The 
time required to produce sufficient roots for transplanting the cut- 
tings varied from two to five months. This period probably could 
have been reduced considerably by the use of bottom heat, such as has 
been advantageously applied in the rooting of some other kinds of 
cuttings. Whole branches used as cuttings will begin to send out new 
leaves from the terminal buds a few days after being set. These 
leaves, which are produced mainly from the reserve nutriment in the 
tissues of the cuttings, will continue to grow, and will cause that 
section of the trunk supporting them to become stunted if the roots 
Figure 25. — A 2-year-old plant which has flowered freely 
but has produced no fruit just coming into bearing 
