Colocasia esculenta (L.) Schott (1832)

Corms underground, starchy; stolons elongate, with nodes produced at or near surface, spreading horizontally. Leaves: petiole green, often purple apically, 30--80(--180) cm, spongy and filled with air spaces; blade green to dark green or glaucous blue-green on adaxial surface, usually with red or purple spot at point of petiole attachment, peltate for 2.5--7 cm, 17--70 ´ 10--40 cm; primary lateral veins parallel, secondary lateral veins netted, forming collective vein between primary lateral veins; apex mucronate. Inflorescences: spathe 20--35 cm; tube green; blade orange outside and in, opening basally and reflexing apically at anthesis to expose spadix, more than 3 times longer than tube; spadix 9--15 cm. Flowers: pistillate flowers pea green, interspersed with white pistillodes; ovaries 1-locular; ovules 36--67; sterile flowers white to pale yellow; staminate flowers and sterile tip pale orange, stamens 3--6, connate. Fruits orange. Seeds 1--1.5 mm, not observed in flora area. 2n = 28, 42 (Old World).

Weeding must be preformed during the first six months after planting. If weeding is not done on a regular basis during the first six months, taro production can be reduced by as much as 50 to 85 percent. Weeding after six months is usually not important because the taro crop forms full ground cover therefore preventing young weeds from growing. Unwanted vegetation can be controlled using mechanical means or through the use of approved herbicides.

The taro must be weeded and mulched several times during the crop’s growth. Commercial fertilizers are also used to produce larger plants.

When the crop is ready to be harvested, the taro are pulled out of the ground and the corms cut off. The new planting material will also be prepared at this time. If the taro is being grown for the leaves, the leaves should be picked about two months after planting when the leaves are large but still young. If the taro is being grown for the corms, then they should be harvested when the corms reach maturity. Taro that is being grown for the corms should not be used for leaves because picking the leaves while the corm is developing will damage the corm.

"Herbs, rhizome stoloniferous. Leaves few to many, peltate, 20-28 x 10-18 cm, ovate, cordate to sagittate at base, glabrous; nerves 6 pairs, united to form an intramarginal vein; lowest pair with lateral nerves of the basal lobes, intercostae curved; petiole 30-45 cm long, cylindrical, smooth. Peduncle solitary or few together, 10-20 cm long, stout; spathe to 20 cm long, yellow, lanceolate, constricted above the base; limb acuminate. Spadix 10 cm long, cylindrical, appendages terete, obtuse. Male flowers above, to 5-6 cm of the spadix, stamens 6; female flowers on lower, 2 cm of the spadix; ovary 1-celled, ovules many on 2-4 parietal placentas. Neutral flowers many, peltate, between the female and male flowers. Fruit an aggregate of berries, globose."

Taro is usually the first crop planted after the clearance of a forest fallow because the soil if very fertile. However after repeated use the soil becomes less productive and will require organic or inorganic fertilizer to maintain high yields. If commercial fertilizer is used be sure not to place the fertilizer in the bottom of the hole with the sucker because the fertilizer will destroy the young sucker.

In the South Pacific, “tiapuli” or setts are prepared from the suckers or main plant. The tiapuli consist of the cormels with the petioles and are the main material used of propagating taro. Small tiapuli used for planting can have a considerable effect on yield if weeding is delayed during early establishment. Large size planting material grows more vigorously, giving full ground cover earlier and hence providing better weed control. Planting depth should be in a furrow or hole about 30 cm deep. Planting should be timed to rainfall with lower rainfall areas planted during the early part of the rainy season for best survival and production. In areas with well-distributed rainfall or if one is using irrigation the effect of planting dates is less important because planting can occur throughout the year. Most of the planting and production operation is manual in small communities except for occasional chemical weed control.

In Hawaii, the planting material is called huli. Huli are the cormels ('oha or keiki) that have been trimmed. When the kalo plant is harvested, the keiki are cut off from the harvested makua plant and their leaves and corms are cut off, leaving only about a quarter of an inch attached to the stem. These huli are then left in a cool, dry place for a day or two to allow the cut to heal before they are planted again. The huli should be kept moist so that they don’t dry out but should not be left in standing water otherwise they will rot. After a day or so, the huli will be ready for planting.Wet kalo is grown in the lowlands and on valley floors in man made terraces (Lo'i) that are irrigated by diverted mountain streams. The huli may be planted in rows or in mounds in the lo'i. They will grow to maturity in 9-14 months, depending on the variety. Wet kalo must have cold water running through it’s lo'i because warm, standing water will cause the kalo to rot.