8 BULLETIN 1167, U. S. DEPARTMENT OF AGRICULTURE. 
cause of the labor and other costs involved in providing supports, 
growers quite frequently omit them (PL VIII), but it is believed 
always at the expense of yield. In Florida a particular disadvantage 
in growing yams on clean-cultivated ground without supports is 
that in the early part of the season the tips of the vines are injured 
by the heat of the surface soil. Reports of experiments in the West 
Indies nearly all indicate that staking the vines pays in increased 
yields. Nearly double the rate for unstaked vines has at times been 
obtained by staking. The results of experiments in Florida confirm 
those obtained elsewhere. 
YAMS AS ORNAMENTALS. 
As a screen for a porch (PL IX, Fig. 1) or an outbuilding the 
yam is a useful ornamental. The vine grows rapidly in a reasonably 
fertile soil, and if sufficient moisture is supplied a prolific growth of 
very attractive foliage is secured. Where the season is of seven or 
eight months' duration a fair-sized tuber may be expected from each 
plant by the time the vine is finally killed by frost. But vigorous 
vine growth may be obtained where the frostless season is much 
shorter, and the use of the yam as a screen or shade alone under 
such conditions is well worth while. 
COST OF GROWING YAMS. 
On account of the deep preparation of the soil required for the 
best results in the field cultivation of yams, the need of the vines 
for support, and the labor and care necessary in the proper harvest- 
ing, curing, and packing of the tubers for shipment, the cost per 
pound to the producer must be greater than for the commoner root 
crops. However, the people accustomed to use yams show a willing- 
ness to pay the necessary price, just as in times of potato scarcity 
people will pay a very high price for this usually moderate-priced 
vegetable. Besides this, the better varieties of yams possess such 
merit that it may fairly be assumed that many fancy markets now 
unfamiliar with the yam will gradually come to demand it as they 
become acquainted with it. 
HANDLING THE YAM CROP. 
HARVESTING AND STORING. 
Yams may be harvested about the time of the first killing frost, 
or some time later if succeeding frosts are not so severe as to en- 
danger the tubers in the ground by freezing. Digging should be 
done with spade or shovel in bright, warm weather in order to per- 
mit the tubers to dry well before being stored or shipped. It is 
preferable to dry the freshly dug yams in the shade rather than to 
expose them to the direct sunlight. 
The tubers must be handled carefully, especially in digging and 
immediately thereafter, since they are then exceedingly tender and 
brittle, and bruise or break very easily. Any bruised or cut sur- 
face should be dried quickly in the sun,, and if the weather is cool 
or damp at time of harvest it is important to let all the tubers cure, 
without touching each other, for several days in a warm, dry, well- 
ventilated room. In subsequent storage the yams should be placed 
