16 BULLETIN 55, HAWAII EXPERIMENT STATION 
Green manure crops greatly benefit Hawaiian soils, many of which 
are lacking in organic matter. 
Some planters consider root cutting, such as is done by the plow, 
of value particularly during certain seasons. The roots of the 
banana plant usually grow out horizontally with little branching. If 
they are severed several feet from the plant the cut ends will send 
out a number of feeders, which spread in all directions. Root 
cutting should be done before the plants begin to fruit. 
In certain parts of Central America where the Gros Michel 
(Bluefields), and other tall-growing varieties are cultivated, banana 
plantations are located on forest-covered areas. The locality is first 
selected, consideration being given such important factors as climate, 
rainfall, drainage, likelihood of damage by flood and wind, and the 
feasibility of obtaining labor and supplying transportation. After 
surveys, trails, roadways, and main drainage ditches are completed, 
the underbrush is cut sufficiently to permit systematic lining and 
staking, after which the planting material is set at intervals of 12 
to 18 feet each way, or otherwise, as the grower decides best. As 
the banana plants develop the land is kept cleared of undergrowth, 
and the remaining trees are removed until finally the forest is 
replaced by the field. The clumps of banana plants will have in- 
creased sufficiently in size and number by the end of the year to 
cover the fields with vegetation maintaining a condition of tem- 
perature and moisture not greatly unlike that formerly existing in 
the virgin forest. (For detailed information on the development 
of banana plantations, see 16, p. 21.) 
The above outlined method, with some modification, might be ap- 
plicable to vast areas of Hawaiian subforest lands at elevations of 
500 to 2.000 feet. The excellent underdrainage of the geologically 
new lava soils would greatly lessen the extensive preparation and 
cultivation necessary on the lower lands where the Chinese variety 
is most commonly grown. 
A survey of the banana-growing possibilities on the island of 
Hawaii at elevations of 500 to 2,100 feet was made by the writer in 
1924. Bluefields, Chinese, and several other varieties of the native 
cooking banana of the Maoli type were found in cultivation in clear- 
ings at elevations up to 2,100 feet. The plants were free from insect 
pests and disease and were making luxuriant growth, producing 
large bunches of fruit, specimens of which on ripening proved to be 
of excellent quality. Although banana culture at the higher eleva- 
tions requires a longer time to mature the fruit than it does at the 
lower levels, cost of production is considerably reduced by the simple 
methods of culture used, and by the natural rainfall, which makes 
irrigation unnecessary. It was also found that enough clean, healthy 
propagating material of the varieties could be assembled and multi- 
plied rapidly to start a plantation of no small consequence, and that 
all the stock needed could be obtained in the Territory, thus pre- 
cluding the introduction of disease and insect pests from other coun- 
tries against which quarantine regulations now exist. 
IRRIGATION AND DRAINAGE 
Where irrigation is to be practiced, the ditches should be laid out 
on contours enabling the water to cover every portion of each division 
