Taro corms packed in a 10kg box for sale.
Taro (Colocasia esculenta L) is a fast-growing crop that takes between 6 and 12 months to mature. The leaf, stalk and corm can be eaten; however, the main part marketed is the corm. Large-corm cultivars are grown for the fresh food market in Australia.
Taro is a resilient crop species, but radiation, temperature and water availability affect the total yield and the time taken to reach maturity. The following information on taro production is based on field observations, local growers' experience and literature, as little research has been conducted in Queensland.
Taro is grown in a range of climatic conditions, but appears to do better in wetter regions. The climate of the North Queensland wet tropics is appropriate for taro cultivation, as long as adequate irrigation and nutrition are provided. Taro is generally grown as an upland crop in North Queensland.
Taro can tolerate waterlogged conditions because of its ability to transport oxygen from the leaves to the root. It can be cultivated under flooded wetland, as may be found along stream banks, or as an upland crop.
Taro crops reportedly yield well if the annual average rainfall is at least 1500 mm and is evenly distributed throughout the growing season. For example, much of the upland taro grown in Hawaii is not irrigated, as crops depend on the regular rainfall. Optimum yields are obtained in areas with rainfall exceeding 2500 mm.
Being adapted to high temperatures and humidity, taro performs well between temperatures of 21oC and 27oC.
Taro will grow on a wide range of soil types from heavy clay loams to light volcanic soils. However, taro will only yield well when planted in fertile, friable soil that has a high water capacit and is rich in organic matter. A slightly acid soil (in the range of pH 5.5 to 6.5) with moderate clay content is ideal.
Permanently moist soils appear to be most desirable to maximise growth and yield. Moisture stress can be detrimental to growth and supplementary irrigation may have to be applied during dry periods.
Establishing and maintaining taro crops
Land preparation and propagation
Land preparation consists of weed removal and cultivation to ensure a friable soil texture. Deep ripping to improve root penetration is recommended if the soil is compacted. Mounding is recommended on the wet tropical coast of North Queensland and in areas where waterlogging or ponding may occur.
As flowering and seed production rarely occurs, taro is propagated by setts, which consist of the lower 30-40 cm of the leaf stalk together with the top 1-3 cm of the corm, from sucker corms and full corms. Healthy and vigorous medium to large setts from the mother plant generally yield higher than small setts. The larger setts also appear to grow faster and hence give better weed control. Setts should be clean, not discoloured or blackened, and free from mould and soft spots.
Planting and harvesting can occur at any time of year in response to consumer demand; however, with a defined alternation of dry and wet seasons, planting is generally done at or shortly before the beginning of the wet season.
Taro may be planted in rows or in plots. Planting holes should be larger than the size of the corm, usually 10-20 cm depending on the size of the sett. Other options are to prepare ridges or furrows, or practise flat planting. Shallow planting will result in corms developing above the ground surface and these exposed corms are more likely to be damaged by insect pests and rodents. Crops should be watered soon after planting to remove air pockets.
Little is known about planting density or distance in North Queensland. Growers generally plant one to three plants per square metre, giving a planting density of around 10,000 to 45,000 plants per hectare. Higher planting density produces more, but smaller, corms (anywhere from about 1500 g down to 400 g) and average yield per plant or per hill is reduced. Spacing of approximately 90 cm x 60 cm is common, and a slightly wider spacing may be used where cloud cover is frequent and growing conditions not optimum. Very wide spacings are not recommended, as this provides opportunity for weed growth.
Taro is one of a few crop species that can adapt to a range of moisture regimes. Overwatering is not harmful to its growth, but supplementary irrigation is essential during the dry season. Growth will be restricted and suckering and/or reduction in quality may occur if plants are water stressed.
Water can be applied by sprinkler, furrow or drip irrigation. The ideal amounts, however, are not known for taro cultivation in North Queensland.
Fertilised taro has been observed to perform and yield better than unfertilised plots, showing evidence of improved corm size and number. Experiments in Hawaii have shown that taro responds to regular applications of nitrogen (N), phosphorus (P) and potassium (K) fertilisers.
Nitrogen appears to be the main requirement. Like all tuberous crops, taro also has a high requirement for potassium, which is essential for starch formation. Liming may be necessary in acid soils. However, applications of fertiliser, especially nitrogen, made after the full canopy has formed may affect eating quality and palatability of the tuber.
Mulching is beneficial, provided the soil is not too high in organic matter already. As mulch breaks down, it improves growth rates by providing nutrients and improving soil structure and moisture.
Harvesting and marketing taro
Taro is harvested when the corm reaches the desired size. Crop duration for the different varieties grown in North Queensland ranges from 8 to 12 months, depending on the management of the crop. At maturity, the leaves begin to turn yellow and the petioles are shorter. The main corms begin to push out of the soil surface, which usually indicates that the crop should be harvested soon.
Harvesting is laborious, with growers pulling out the matured corms by hand. The main corms and secondary suckers are broken and loosened from the soil manually. The corms are then pulled out by hand, and these are washed to remove roots and soil and placed in bins for grading and packing. The skin is resistant to mechanical damage during handling.
Yields are variable, in the region of 4-20 t/ha. Yields up to 70 t/ha have been recorded in Hawaii with heavy fertilisation. A low yield of 2440 kg/ha is quite easily achievable.
Grading and storage
Corms are graded according to size or weight, depending on the market. The preferred corm weight is between 1 kg and 1.5 kg, depending on the variety. The cut flesh should look and smell fresh and juicy, and only quality corms with no rot or other blemishes should be packed. Buyers look for firm corms.
Under ambient temperature, taro does not store very well and should be consumed within two weeks. Refrigeration appears to extend storage life. It has been suggested that growers might market the corms with 5 cm green tops as this could extend shelf life.
In Australia, taro is sold mainly through specialty agents in Brisbane, Sydney and Melbourne, with some direct sales to retailers. Taro prices on the wholesale market are generally around $3 to $4 per kilogram. Corm weights of around 1-1.5 kg are desirable, although there appears to be an increasing preference for smaller taro.
There is a potential small corm (Jap taro) market in Japan; however, this market is yet to be tested. Due to insufficient production data and a firm idea of market prices, the economics for taro production is not established.
- About taro
- Taro pests and diseases
- Lambert, M (ed.) 1982, Taro cultivation in the South Pacific, South Pacific Commission, Noumea, New Caledonia.
- Purseglove, JW 1972, Tropical crops. Monocotyledons 1, Longman Group Limited.
- Tips for a successful business
- Horticulture and climate change
- Producing vegetables for a market
- Customer Service Centre