Agriculture Reference
In-Depth Information
5.7.4 Diseases, Insect Pests, and Their Control
The fungus Pythium is the major microbial disease of taro root and can cause significant
losses in yield. The fungus Phytophthora is the major disease of taro leaves. Tools used
in harvest are frequently disinfected with bleach, alcohol, or hydrogen peroxide,
especially when huli to be used for a future crop are harvested. This prevents the
spread of disease organisms. Only disease-free huli are then used for subsequent
crop production.
Both root aphid and leafhoppers are major insect pest of taro, although there are
also a number of other common pests such as mealybugs, snails, and slugs, which
can also cause yield losses, and nematodes, which will attack corms causing yield
loss and decrease in corms.
As with all crops, rotation and leaving fields without crops for a period of time are
effective in decreasing the incidence of disease and insects. However, there are also some
recommended practices such as isolation of fields, planting in small fields, intercropping,
and maintaining the soil pH close to neutral, which are practices different from those
commonly applied to potatoes, sweet potatoes, cassava, and the other tuber crops.
5.7.5 Harvesting and Postharvest Practices
Dry-land production takes from 5 to 12 months, while flooded production takes from 12
to 15 months. A general yellowing of the leaves indicates that the crop is ready for
harvest, which is commonly done by hand. Dry-land harvesting is easer than
flooded, as the roots in flooded conditions must be cut or broken to remove the
corms. Once harvested, the corms are dried and can be stored for short periods of
time in this condition.
Generally, taro is eaten shortly after harvest and thus is not generally stored. Some-
times processed into flakes or flour, taro can be stored for some time in this condition.
However, this is not a common practice, and taro in these or other processed forms is
not commonly nor regularly found.
5.7.6 World Production
The largest producers of taro are Nigeria, Ghana, and Cˆ te d'Ivoire, all in Africa. This,
however, should not lead one to the conclusion that taro is not important in the Pacific
islands; it is. As can be seen in Figure 5.13, taro production is mostly limited to the tro-
pical countries of the Pacific Ocean, Africa, and South America, although some is grown
in the United States and China. Also total hectareages planted is quiet small when com-
pared to other root crops. Nevertheless some peoples in these areas depend on taro as
their major source of carbohydrates in the diet.
5.7.7 World Trade
On a worldwide bases there is little trade in taro, as can be seen in Table 5.6. China is
the largest exporter followed by Fiji Islands, which exports less than one tenth the
