Both species of Alocasia are very hardy and high yielding.
Colocasia and Xanthosoma are similar crops; they are complementary, not
competitive, because they are adapted to different growing conditions. Xanthosoma
are more drought tolerant than Colocasia, and they grow better in the shade. Both
types are highly resistant to attack by pests and diseases.
The description below refers to the two species:
Colocasia esculenta var. esculenta—normally called the Dasheen;
Colocasia esculenta var. antiquorum—normally called the Eddoe.
PLANTING
Propagation:
Dasheen—either by the leaf-bearing tops of mature corms, especially in the Pacific,
or by small side tubers or suckers;
Eddoe—small cormels (60–150 g) are planted whole.
Soil: the best are forest soils that have been cleared and burned for the first time.
Soils should be wet, heavy and fertile. Eddoes need less fertile soils than dasheens.
Some varieties are tolerant of flooding and salinity. Both normally respond well to
potash as well as nitrogen and phosphate, normally applied in two or three split
dressings.
Spacing: roughly 60–90 cm if grown in pure stands.
Intercropping: this is the normal method, mixed with okra, pigeon peas, maize, etc.
GROWTH CONDITIONS
Growth period: 5–6 months for eddoes, 8–10 months for dasheens.
Temperature: they need hot conditions; eddoes withstand low temperatures better
than dasheens, which need about 6 or 7 frost free months. The optimum daily
temperature is 21–27C.
Rainfall: dasheens need about 2500 mm per year, eddoes need less.
Pests: Taro Leafhopper (Tarophagus. proserpina), can be biocontrolled with Mirid
bugs; Gabi Moth larvae can cause major defoliation; Root-knot nematodes are a
serious pest in some countries.
Diseases: Taro Leaf Blight is usually the most serious, especially in the Pacific.
Symptoms are round, water-soaked dead spots on the leaves, then the plant collapses
and dies. Some control with fungicides such as Dithane. Root rots and virus diseases
may also be a problem.
YIELD
Dasheen—small side suckers are left in the ground after harvest and allowed to
regrow, or ratoon. The ratoon crop is often grown only for the leaves. Average
yields of corms are 15–20 MT/ha for the first harvest and 10–15 MT/ha for the first
ratoon crop.
40 MT/ha and more is possible.
Eddoe—this crop is not ratooned. The corms and cormels can be left “stored” in the
ground until needed during the dry season. The main, central corm is relatively small
but has many side cormels.