18 BULLETIN 55, HAWAII EXPERIMENT STATION 
trees can be prevented from encroaching on the zone occupied by the 
bananas by maintaining a narrow ditch 3 or 4 feet in depth at a 
distance of about 4 feet from the row of trees adjoining the field. 
Good examples of controlling horizontal root growth of wind- 
breaks are to be found in different parts of the Territory. Vigorous 
and prolific plants can be grown in close proximity to tree wind- 
breaks where the ditch method is used. A windbreak of round, 
dense-topped trees intermixed with the taller topped forms makes 
an irregular and more satisfactory shelter than one of uniformly 
tall, dense trees. 
PRUNING 
Both vigor and productivity of the banana plant are greatly in- 
creased by proper sucker pruning. The plants soon lose their 
ability to collect and assimilate sufficient plant food to maintain all 
their suckers when developed to abnormally large fruiting condi- 
tions, as is often done for commercial purposes. Fruit of improved 
size and quality can be had by pruning out the poorer suckers and 
forcing each clump to produce two to four fruiting trunks. Grow- 
ers may time their crops to meet market demands. By choosing 
the right time to start new suckers, it is possible to bring in the 
greater part of the crop during the season of highest prices. 
A thorough knowledge of pruning requires considerable study and 
practice. The difference between desirable and undesirable small 
suckers is hard to determine. Undesirable specimens should be 
removed before attaining a height of 2 feet, for the larger they 
grow the more food they will take from the parent plant, and the 
more their young roots will interfere with the root system of the 
clump. Selected suckers of a size for transplanting should be so 
carefully removed as not to injure remaining suckers or the core 
and root system of the parent. The roots of the severed sucker 
should be removed before transplanting. 
Practically all the work in sucker pruning is done with a long- 
handled, chisellike cutting tool, commonly called a " sucker spud," 
which is very similar to the Hawaiian a o-o." After removal of 
some of the soil from around the sucker the spud is forced straight 
down between the sucker and the corm of the parent plant to mgke 
a clean cut without bruising either. In pruning out small, unde- 
sirable suckers care must be taken to cut far enough into the hard, 
Avhite part of the corm to prevent the suckers from sprouting again 
ana necessitating a repetition of the work. 
The large terminal bud of the flower stalk may be pruned out 
when the fruit has set and a few clusters of the staminate flowers 
have fallen. When the earlier leaves of the plant complete their 
assimilative function they hang pendant around the trunk, protect- 
ing it from the rays of the sun. If they are pruned out, the outer 
sheathing of the trunk may be injured and the whole plant may 
sutler . The dead leaves may be pruned out, however, and used for 
wrapping the fruit for shipment when the plants are set close to- 
gether and the trunks are Avell shaded by the foliage. When a 
iDimch of fruit forms about a leaf petiole the leaf should be pruned 
out to prevent its causing any irregularity of the fruit. 
