EDIBLE CANNA IN WAIMEA DISTRICT OF HAWAII 9 
Boil 2 pounds of white arsenic and 0.42 pound of caustic soda in water until 
the solution becomes clear. This is made up to 1 gallon with water. For the 
succulent plants like honohono, dilute to 25 gallons, and for grasses such as 
Panicum, dilute to 10 gallons. Soap added at the rate of 1 pound per 100 gallons 
of spray increases the effectiveness of the spray. 
Poison bait should be used to control cutworms which attack 
young fields of canna during the late spring and early summer. A 
number of formulas suitable for the purpose have been published by 
the station (1, p. 7). 
WINDBREAKS 
During the greater part of the year the Waimea district is swept 
by high winds which shred the leaves of the canna plant, draw mois- 
ture from the soil, and otherwise prevent normal growth. Crops 
which are protected by windbreaks make more vigorous and thrifty 
growth than do those left exposed in the open. 
Trees and plants which are used for windbreaks in the Waimea 
district include eucalyptus (fig. 3), black wattle, Monterey cypress 
Fig. 3.— Eucalyptus windbreak, showing paucity of foliage near the base 
(fig. 4), castor-bean trees (fig. 5), and the banana plant, and combi- 
nations of these. The eucalyptus is quick growing, attains sufficient 
height in three or four years to protect a field, and has the additional 
value of supplying fairly good fence posts and firewood when the trees 
are thinned out or pruned. The black wattle also is quick growing 
and furnishes more durable posts than the eucalyptus, but bends 
with the wind to such an extent as to utilize too much ground. The 
Monterey cypress requires 10 to 12 years to attain a height sufficient 
to protect a field, but makes an ideal windbreak when it is planted in 
combination with eucalyptus or black wattle. The Monterey 
cypress makes straight growth, attains good height, and covers com- 
paratively little area. The lower branches of the eucalyptus die 
when the tree is about 15 feet high, and the spaces left by these should 
be filled by the slow-growing cypress. After 10 or 12 years, when the 
faster growing trees are removed for fence posts or firewood, the cypress 
can carry on alone. (Fig. 6.) Any variety of banana plant which does 
83065—28 2 
