Template:Chapters 5.12

5.12 -Taro: Production outline, challenges, and opportunities

Zach Telfer, University of Guelph, Canada

Suggested citation for this chapter.

Telfer,Z. (2022) Taro: Production outline, challenges, and opportunities. In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org

Overview of Taro Production

Taro (Colocasia esculenta (L.) Schott) is a tropical crop primarily grown in Asia, Africa, and Oceania (Miyasaka et al., 2012). The corm at the base of the plant, where the roots and leaves grow from, constitutes the main edible part (Onwueme, 1999). Nigeria produces the largest acreage (>800,000 ha) while Cameroon, Ghana and China contribute significant acreage for a global production of 10.2 tonnes across 1.7 million ha (FAO, 2019). Conventional taro production in Hawai’i can produce a net return of over $1000/acre based on corm sales (Miyasaka et al., 2001) whereas taro is often grown for subsistence or local market sale in West Africa (Ubalua et al., 2016). The corm is roughly two-thirds water, and the rest is primarily starch, while it is also rich in potassium, phosphorus, magnesium, calcium, zinc and iron (Mergedus et al., 2015). Corms can contain 7% protein by dry weight but are low in several amino acids including histidine, lysine, isoleucine, tryptophan, and methionine (Onwueme, 1999). As a secondary food item, taro leaves can provide important minerals and vitamins including iron, copper, magnesium, potassium, and zinc (Gupta et al., 2019), fiber (Miyasaka et al. 2012), and folic acid (Rao et al., 2010). Climate change is forecasted to significantly alter the global water cycle, with certain regions receiving more rainfall while others will experience decreases (Collins et al., 2013). African growers, for example, have acknowledged that climate change is a significant threat to their production system as rain infrequency is already an issue (Bammite et al., 2018). Taro presents an opportunity for smallholders to adapt to these changing parameters. Taro is shade tolerant and can benefit as an under-canopy crop from the microclimatic conditions created by trees (Sanou et al., 2012), shielding itself from direct heat. Furthermore, Taro's ability to grow in poorly drained soils can allow for crop productive in underutilized land (Amadi et al., 2015), particularly lands that become flooded.

Factors that Impact Taro Production

Taro is a water demanding crop, but this varies between cultivars. Taro can be grow throughout its entire life cycle on flooded lands (wetland production) where 2500 mm rainfall is optimal for yield (Ganança et al., 2018). However in dryland production, water requirements are estimated at 1500-2000 mm (Onwueme, 1999). Taro should be planted at the onset of the main rainy season (Onwueme, 1999) as high rainfall is most critical during the first 20 weeks of growth (Ubalua et al., 2016). Planting materials consist of: suckers produced by the plant; small corms from the previous crop; Huli - the apical 1-2 cm of corm with a 15-20 cm length of petiole; or corm pieces from a previous harvest; if using corm pieces, it is advised to pre-sprout them before planting (Onwueme, 1999). Dryland taro is best planted on ridges made 70-100 cm apart, with the plants on the top of the ridge 50-90 cm apart (Onwueme, 1999). Though taro can tolerate production in shaded environments, as noted earlier, full sun produces the highest yields (Djukri, 2006). This allows taro to be intercropped; additional taro plants or an intercrop can be planted in the furrows of the ridges (Onwueme, 1999). Examples of taro intercrops include black pepper (Silbanus and Raynor, 1992), young rubber trees (Djukri, 2006), Bambara groundnut (Mabhaudhi and Modi 2014), maize (Rao et al., 2010; Singh et al., 2012), rice, ginger, legumes, or sweet potatoes (Rao et al., 2010). Annual intercrops should be planted simultaneously with taro to allow for intercrop harvest before it competes with the taro (Onwueme, 1999). Mulching, particularly with rice husks, increases yield in part due to improved water management (Juang et al., 2020), however organic inputs are often too expensive to produce an economic return from taro despite yield increases (Miyasaka et al., 2001). Wetland taro can be planted into water-retaining soils similar to rice paddy (Onwueme, 1999). Corm production requires a 12-15 month growing season (wetland taro) or 5-12 months (upland taro), and the plant clearly signals corm maturity by the yellowing and death of the outer leaves (Onwueme, 1999).

Weeding is a production constraint for taro production in West Africa (Bammite et al., 2018). Wetland taro is typically highly effective at mitigating weeds as most weeds cannot survive in the flooded cropland, while upland taro requires weed control for the first three months (canopy closure prevents weed issues afterwards) (Onwueme, 1999). Taro is susceptible to herbicides (Bammite et al., 2018), but nitrofen at 3-6 kg/ha for wetland taro, or Promtryne at 1.2 kg/ha, Dalapon at 3 kg/ha, Diuron at 3.4 kg/ha or Atrazine at 3.4 kg/ha for upland taro are effective (Onwueme, 1999). Hand weeding taro at 30, 60, 90, and 120 days after planting can significantly improve yield and can even justify the hiring of people to ensure it is complete so long as the labour cost is low (Ragus et al. 1993),

Taro leaf blight disease, caused by the fungus, Phytopthora colocasiae, can cause complete loss of harvestable corms (Singh et al., 2012). The disease has significantly disrupted Samoan, Dominican Republic, Cuba, and Puerto Rican production (Singh et al., 2012). This blight is a threat to African production, with incidences in Nigeria, Ghana, and complete destruction of the crop documented in Cameroon (Grimaldi et al., 2018). Disease symptoms present as an expanding water soaked lesion that dries during the day and eventually produces amber/orange droplets (Singh et al., 2012). Taro leaf blight can be controlled using metalaxyl and phosphoric acid, although mancozeb and copper provide protection if applied before infection (Singh et al., 2012). Cultural management practices for taro leaf blight include increasing the distance between plants at planting, and intercropping. Ensuring the removal of infected leaves is the most critical and impactful non-chemical management practice but is not helpful during a large outbreak where it could mean the loss of all yield (Singh et al., 2012).

Taro beetles (Papuana spp.) are a significant insect issue in the Pacific region, as the adults directly feed on the corm and live for nearly two years, although imidacloprid and bifenthrin are effective at protecting the crop from infestations (Brown and Daigneault, 2014). Flooding the land or planting into mulch reduces the population of these beetles, or the beetle seems to be unable to live on plots shaded by vined intercrops (Lebot 2020) Aphids and root knot nematode (Meloidogyne spp) are also common issues (Cho et al., 2007; Lebot 2020).

Taro Breeding

Regions where taro has been introduced typically have low genetic diversity, as taro primarily reproduces vegetatively (Kreike et al., 2004). Southeast Asia is the evolutionary origin of taro (Singh et al., 2012). Taro breeding typically requires artificial stimulation of flowering with the plant hormone gibberellic acid to enable sexual reproduction (Amadi et al., 2015). Complicating breeding, taro has both diploid and triploid lines (Amadi et al., 2015). Currently, there is no CGIAR (Consultative Group for International Agricultural Research) mandate for taro breeding, but the Pacific Islands and CePaCT (Centre for Pacific Crops and Trees) now has mandate to support worldwide breeding activities and has over 800 accessions of taro (Taylor et al., 2009).Currently, CePaCT relies on national partnerships for the sharing of taro accessions, but is working to develop pathways to reach farmers more directly through NGOs, researchers, or producer organizations (Ebert and Wagainabete, 2018)

There is a major divide in variety types of taro. The dasheen type (C. esculenta esculenta) produces a single large corm for harvesting, while the eddoe (C. esculenta antiquorum) type produces a smaller corm with multiple side cormels which can all be harvested (Mikami and Tsuitsui, 2019). Some cultivar impacts have been noted for different production types. The cultivars Aweu and Bun-Long perform well under flooded conditions due to superior formation of the arenchyma which allow oxygen to reach the flooded roots (Abiko and Miyasaka, 2020). Bun-long is also noted for its favourability in producing taro chips (Cho et al., 2007). Landraces from Umbumbulu, South Africa, are used in upland production and have been noted to tolerate lower water availability (Mabhaudhi et al., 2013). Major traditional breeding efforts have been put forward to breed for taro leaf blight resistance (Singh et al., 2012). Successes have been documented (Taylor et al., 2009; Lebot et al., 2018), with taro leaf blight immunity noted in Malaysian cultivars: Hitan, Cina, Jenjarum (Lebot et al., 2018). Genetic modification (GMO) technology has also been used to create taro leaf blight resistance, although several regions have banned the production of GMO taro, such as Hawaii (He et al., 2010). Ultimately, breeding advances can improve several aspects of taro production including water requirements, disease protection, and acridity. However, crop advancements need to be paired with local, accessible production guides to mitigate climate change. Ultimately, breeding advances can improve several aspects of taro production including water requirements, disease protection, and acridity. However, crop advancements need to be paired with local, accessible production guides to mitigate the impacts of climate change.

Cooking and Post-Harvest Strategies for Taro

Raw taro consumption causes irritation or stinging effects within the mouth and can be difficult to digest, so cooking is required prior to consumption; cooking with acidic ingredients or baking soda can improve food acceptability (Rao et al., 2010). Once cooked, the starches in taro are highly digestible for humans and represent a beneficial dietary carbohydrate for people with diabetes (Simsek and Nehir El., 2015). The Pacific Islands have a variety of production methods revolving around fermenting and cooking the taro corm (Rao et al., 2010); elsewhere the corms are typically boiled or roasted (Singh et al., 2012) or fried as chips or fries which attracts an international market (Lebot 2020). Cooked taro can also be made into a paste (Lebot 2020), mixed with cassava or cereals or prepared into a flour (Bammite et al., 2018). In Indonesia, engaging a woman’s farmer group to turn taro into a flour or chip was shown to increase revenue by 3-7 times (Elisabeth 2015). In West Africa, mashed taro is often used as a weaning diet, while the flour is commonly used to prepare ‘fufu’ that is a component of stews (Opara 2003). The taro leaves are frequently eaten as a vegetable that requires cooking as well (Bammite et al. 2018) and are best consumed when they are young. which can however reduce corm production (Ebert et al., 2018). Cooking leaves with coconut cream is a popular form of preparation (Opara 2003). Leaves can also be steamed and then ground into a powder for months of storage (Rao et al., 2010)

The high moisture content of taro produces storage difficulties (Lebot 2020). Since taro is propagated vegetatively, issues with storing taro can lead to lack of planting materials (Opara 2003; Ifeanyi-obi et al., 2017). At ambient temperatures, taro stores for 2-4 weeks but can drop significantly in weight due to moisture loss during that time (Paull and Cheng Chen, 2015). Ideally, taro is stored in a room at 10-14˚C with 80-90% RH, which allows for 18 weeks of stable storage (Paull and Cheng Chen, 2015). Without climate controlled facilities, taro corms can be stored in a cool, shaded place for up to one month although they should be sun dried prior to storage; storing in a polyethylene bag is equally effective (Lebot 2020). There are opportunities for cooperatives to form effective exporting businesses around taro; Nicaragua experienced a taro boom between 2006-2014, with the country shipping nearly $10 million of taro per year to the United States, however strong production practices and an established relationships with the receiving country/importer are critical to ensure that a high quality product is well received (Donovan et al., 2017). Since the majority of taro is produced in West African countries, there is significant potential for trade growth as currently essentially none of this production reaches international trade markets (Ubalua et al., 2016).

Future Reading/Helpful Tips and Links

Taro Planting https://www.youtube.com/watch?v=wfOKKgI9WAs

Taro Harvest and Cleaning of Corm https://www.youtube.com/watch?v=fpA7axC7SY8

How to Cook Taro https://www.youtube.com/watch?v=ALy95vqHrM0

Cooking Taro Chips of Fries https://www.youtube.com/watch?v=QW6vNGG9m-g

Cooking Taro Leaves https://www.youtube.com/watch?v=uobhYCEXNQg

Hawai'an Taro Farm - with tips of wetland harvesting, planting, and cooking https://www.youtube.com/watch?v=KiVtltb2zxs

Taro Planting Details

https://greenharvest.com.au/Plants/Information/Taro.html

Taro Extension Pamphlet – India http://www.kiran.nic.in/pdf/farmers_corner/newpamplets/Taro.pdf

Growing root crops on Atolls – has pictures and info for nutrient deficiency, pests, diseases http://www.spc.int/DigitalLibrary/Doc/LRD/Agriculture/Crops_manual_attols_final_web.pdf

Taro Leaf Blight Management www.ctahr.hawaii.edu/oc/freepubs/pdf/PD-71.pdf

Propagating taro by the normally dormant buds present on huli and corm www.ctahr.hawaii.edu/oc/freepubs/pdf/PN-021.pdf

Taro Cultivation in Asia and the Pacific – production guidelines http://www.fao.org/3/AC450E/ac450e00.htm

Comparison of Taro Production and Constraints between West Africa and the Pacific https://lrd.spc.int/genetic-resources-publications/doc_download/609-gr-ts-t3-kwadwo-ofori-samoa

Global Crop Diversity Trust Taro Production Guidelines https://www.genebanks.org/resources/publications/descriptors-taro/

Processing Taro Chips www.ctahr.hawaii.edu/oc/freepubs/pdf/FMT-1.pdf

Centre for Pacific Crops and Trees (CePaCT) https://www.croptrust.org/genebank/secretariat-of-the-pacific-community-center-for-pacific-crops-and-trees-cepact/

References

1. Abiko, T., & Miyasaka, S. C. (2020). Aerenchyma and barrier to radial oxygen loss are formed in roots of taro (Colocasia esculenta) propagules under flooded conditions. Journal of Plant Research, 133(1), 49–56. https://doi.org/10.1007/s10265-019-01150-6

2. Amadi, C. O., Onyeka, J., Chukwu, G. O., & Okoye, B. C. (2015). Hybridization and Seed Germination of Taro (Colocasia esculenta) in Nigeria. Journal of Crop Improvement, 29(1), 106–116. https://doi.org/10.1080/15427528.2014.980023

3. Bammite, D., Matthews, P. J., Dagnon, D. Y., Agbogan, A., Odah, K., Dansi, A., & Tozo, K. (2018). Constraints to production and preferred traits for taro (Colocasia esculenta) and new cocoyam (Xanthosoma mafaffa) in Togo, West Africa. African Journal of Food, Agriculture, Nutrition and Development, 18(2), 13388–13405. https://doi.org/10.18697/ajfand.82.17360

4. Brown, P., & Daigneault, A. (2014). Cost — Benefit Analysis of Managing the Papuana uninodis (Coleoptera : Scarabaeidae) Taro Beetle in Fiji Cost – Benefit Analysis of Managing the Papuana uninodis (Coleoptera : Scarabaeidae) Taro Beetle in Fiji. Journal of Economic Entomology, 107(5), 1866–1877. https://doi.org/10.1603/EC14212

5. Cho, J. J., Yamakawa, R. A., & Hollyer, J. (2007). Hawaiian kalo, past and future. Honolulu, Hawaii. Retrieved from https://scholarspace.manoa.hawaii.edu/bitstream/10125/12594/1/SA-1.pdf

6. Collins, M., Knutti, R., Arblaster, J., Dufresne, J. L., Fichefet, T., Friedlingstein, P., … Wehner, M. (2013). Long-term climate change: Projections, commitments and irreversibility. In T. F. Stocker, D. Qin, P. G. K, M. Tignor, S. K. Allen, J. Boschung, … P. M. Midgley (Eds.), Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 1029–1136). Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press. https://doi.org/10.1017/CBO9781107415324.024

7. Djukri, D. (2006). The plant characters and corm production of taro as catch crop under the young rubber stands. Biodiversitas, 7(1994), 256–259. https://doi.org/10.13057/biodiv/d070312

8. Donovan, J., Poole, N., Poe, K., & Herrera-arauz, I. (2018). Ambition meets reality: lessons from the taro boom in Nicaragua meets reality. Journal of Agribusiness in Developing and Emerging Economies, 8(1), 77–98. https://doi.org/10.1108/JADEE-02-2017-0023

9. Ebert, A. W., & Waqainabete, L. M. (2018). Conserving and sharing taro genetic resources for the benefit of global taro cultivation: A core contribution of the centre for pacific crops and trees. Biopreservation and Biobanking, 16(5), 361–367. https://doi.org/10.1089/bio.2018.0017

10. Elisabeth, D. A. A. (2015). Added value improvement of taro and sweet potato commodities by doing snack processing activity. Procedia Food Science, 3, 262–273. https://doi.org/10.1016/j.profoo.2015.01.029

11. FAO (Food and Agriculture Organization of the United Nations). (2019). FAOSTAT Statistical Database. Rome. Retrieved from http://www.fao.org/faostat/en/#data

12. Ganança, J. F. T., Freitas, J. G. R., Humberto, G. M., Rodrigues, V., Antunes, G., Gouveia, C. S. S., … Lebot, V. (2018). Screening for drought tolerance in thirty three taro cultivars. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 46(1), 65–74. https://doi.org/10.15835/nbha46110950

13. Grimaldi, I. M., Leke, W. N., Borokini, I., Wanjama, D., & Van Andel, T. (2018). From landraces to modern cultivars: field observations on taro Colocasia esculenta (L.) Schott in sub-Saharan Africa. Genetic Resources and Crop Evolution, 65(7), 1809–1828. https://doi.org/10.1007/s10722-018-0651-4

14. Gupta, K., Kumar, A., Tomer, V., Kumar, V., & Saini, M. (2019). Potential of Colocasia leaves in human nutrition: Review on nutritional and phytochemical properties. Journal of Food Biochemistry, 43(7), 1–16. https://doi.org/10.1111/jfbc.12878

15. He, X., Misayaka, S. C., Zou, Y., Fitch, M. M. M., & Zhu, Y. J. (2010). Regeneration and transformation of taro (Colocasia esculenta) with a rice chitinase gene enhances resistance to Sclerotium rolfsii. HortScience, 45(7), 1014–1020. https://doi.org/10.21273/HORTSCI.45.7.1014

16. Ifeanyi-obi, C. C., Togun, A. O., Lambdoll, R., & Arokoyu, S. (2017). Socio-economic determinants of cocoyam farmer’s strategies for climate change adaptation in southeast Nigeria. Journal of Agricultural Extension, 21(2), 91–104. https://doi.org/10.4314/jae.v21i2.8

17. Juang, K. W., Lin, M. C., & Hou, C. J. (2020). Influences of water management combined with organic mulching on taro plant growth and corm nutrition. Plant Production Science, 1–18. https://doi.org/10.1080/1343943X.2020.1820877

18. Krieke, C. M., Van Eck, H. J., & Lebot, V. (2004). Genetic diversity of taro, Colocasia esculenta (L.) Schott, in Southeast Asia and the Pacific. Theoretical and Applied Genetics, 109, 761–768. https://doi.org/10.1007/s00122-004-1691-z

19. Lebot, V. (2020). Tropical root and tuber crops: cassava, sweet potato, yams and aroids (Second Edi). Wallingford, UK: CAB International. https://doi.org/10.1079/9781789243369.0000

20. Lebot, V., Tuia, V., Ivancic, A., Jackson, G. V, Saborio, F., Reyes, G., … Iosefa, T. (2018). Adapting clonally propagated crops to climatic changes: a global approach for taro (Colocasia esculenta (L.) Schott). Genetic Resources and Crop Evolution, 65, 591–606. https://doi.org/10.1007/s10722-017-0557-6

21. Mabhaudhi, T., Modi, A. T., & Beletse, Y. G. (2013). Response of taro (Colocasia esculenta L. Schott) landraces to varying water regimes under a rainshelter. Agricultural Water Management, 121, 102–112. https://doi.org/10.1016/j.agwat.2013.01.009

22. Mabhaudhi, T., & Modi, A. T. (2014). Intercropping taro and bambara groundnut. In E. Lichtfouse (Ed.), Sustainable Agriculture Reviews: Volume 13 (pp. 275–290). Switzerland: Springer International Publishing. https://doi.org/10.1007/978-3-319-00915-5_9

23. Mergedus, A., Kristl, J., Ivancic, A., Sober, A., Sustar, V., Krizan, T., & Lebot, V. (2015). Variation of mineral composition in different parts of taro (Colocasia esculenta) corms. Food Chemistry, 170, 37–46. https://doi.org/10.1016/j.foodchem.2014.08.025

24. Mikami, T., & Tsutsui, S. (2019). Taro (Colocasia esculenta (L.) Schott) production in Japan: Present state, problems and prospects. Acta Agriculturae Slovenica, 114(2), 183–189. https://doi.org/10.14720/aas.2019.114.2.4

25. Miyasaka, S. C., Hollyer, J. R., & Cox, L. J. (2001). Impacts of organic inputs on taro production and returns. Honolulu, Hawaii. Retrieved from https://scholarspace.manoa.hawaii.edu/bitstream/10125/12451/1/SCM-3.pdf

26. Miyasaka, S. C., McCulloch, C. E., & Nelson, S. C. (2012). Taro germplasm evaluated for resistance to taro leaf blight. HortTechnology, 22(December), 838–849. https://doi.org/10.21273/HORTTECH.22.6.838

27. Onwueme, I. (1999). Taro cultivation in Asia and the Pacific (Vol. RAP Public). Bangkok, Thailand. Retrieved from http://www.fao.org/3/AC450E/ac450e00.htm

28. Opara, L. U. (2003). Edible aroids: Post-harvest operations. INPhO - Post-harvest Compendium. https://doi.org/10.1007/978-1-4615-6015-9_13

29. Paull, R. E., & Cheng Chen, C. (2015). Taro: Postharvest quality-maintenance guidelines. Honolulu, Hawaii. Retrieved from www.ctahr.hawaii.edu/oc/freepubs/pdf/VC-5.pdf

30. Ragus, L. N., Almario, V. M., & Richards, H. (1993). Yield and profitability of taro production under three weed management schemes at Rota, Commonwealth of the Northern Mariana Islands. Honolulu, Hawaii. Retrieved from https://www.ctahr.hawaii.edu/oc/freepubs/pdf/RES-140-30.pdf

31. Rao, V. R., Matthews, P. J., Eyzaguirre, P. B., & Hunter, D. (Eds.). (2010). The global diversity of taro ethnobotany and conservation. Biodiversity International. Rome, Italy. Retrieved from https://www.bioversityinternational.org/e-library/publications/detail/the-global-diversity-of-taro-ethnobotany-and-conservation/

32. Sanou, J., Bayala, J., Bazié, P., & Teklehaimanot, Z. (2012). Photosynthesis and biomass production by millet (Pennisetum galucum) and taro (Colocasia esculenta) grown under baobab (Adansonia digitata) and nere (Parkia biglobosa) in an agroforestry parkland system of Burkina Faso (West Africa). Experimental Agriculture, 48(2), 283–300. https://doi.org/10.1017/S0014479712000014

33. Silbanus, S., & Raynor, B. (1992). Intercropping colocasia taro with black pepper (Piper nigrum) on Pohnpei. Honolulu, Hawaii. Retrieved from www.ctahr.hawaii.edu/oc/freepubs/pdf/PN-021.pdf

34. Simsek, S., & Nehir El, S. (2015). In vitro starch digestibility, estimated glycemic index and antioxidant potential of taro (Colocasia esculenta L. Schott) corm. Food Chemistry, 168, 257–261. https://doi.org/10.1016/j.foodchem.2014.07.052

35. Singh, D., Jackson, G., Hunter, D., Fullerton, R., Lebot, V., Taylor, M., … Tyson, J. (2012). Taro leaf blight — A threat to food security. Agriculture, 2, 182–203. https://doi.org/10.3390/agriculture2030182

36. Taylor, M., Tuia, V., Kambuou, R., & Kete, T. (2009). Root and tuber crops of the Pacific: A resource for meeting the challenges of the 21st century. In 15th Triennial ISTRC Symposium (pp. 14–22). Lima. Peru: International Society for Tropical Root Crops. Retrieved from http://www.istrc.org/images/Documents/Symposiums/Fifthteenth/s1_taylor.pdf

37. Ubalua, A. O., Ewa, F., & Okeagu, O. D. (2016). Potentials and challenges of sustainable taro (Colocasia esculenta) production in Nigeria. Journal of Applied Biology & Biotechnology, 4(01), 053–059. https://doi.org/10.7324/jabb.2016.40110