Chapters 5.21
5.21 -the Potential that Dragonfruit Holds to Help Smallholder Farmers Adapt to Drought/Climate Change
Breanne Duncan, University of Guelph, Canada
Suggested citation for this chapter.
Duncan,B. (2022) the Potential that Dragonfruit Holds to Help Smallholder Farmers Adapt to Drought/Climate Change, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Overview of Dragon Fruit Potential
Dragon fruit (Hylocereus undatus) (Kishore, 2016) is recognized across the globe with names such as Pitaya, Pitahaya, Strawberry pear, or night blooming Cereus (Castro et al., 2018). Hylocereus undatus was subjected to human selection in the Mayan lowlands in Mexico before 3400 BC, and is presently popular today within tropical regions of northern South America, Central America & Mexico. There is no doubt that Dragon fruit has gained an increase in demand due to the attractive colour of its edible fruit, as well as its rich nutrient and potential health properties — and as a result has become an increasingly important, successfully cultivated crop on smaller scale farms in places like Vietnam, Colombia, Ecuador, USA, Thailand, Japan and Australia (Mustafa et al ., 2018). Today, dragon fruit has become an excellent crop to assist smallholder women farmers, not only as a channel of support for their families, but also as an aid to combat climatic changes (Kishore, 2016).
H. undatus belongs to a group of night blooming, semi-epiphytic climbing cacti (Castro, 2018). It particularly belongs to the genus Hylocereus which itself has 14 species (Hart, 2005). A long-term breeding program using Hylocereus undatus seeds/materials was started at Ben Gurion University of the Negev in Israel, whose goal was to improve fruit traits and yields of the easily intercrossed but under researched crop (Tel-zur, 2015). H. undatus is a diploid, perennial crop that proves to be a very viable option for dry land agriculture in arid/semi-arid regions which are exceedingly getting warmer due to climate change (Castro, 2018). This is because the semi-epiphytic cactus dragon fruit possesses the Crassulacean acid metabolism (CAM) photosynthetic pathway, which reduces the plants water loss during the daytime (Tel-zur, 2015). This demonstrates the plants potential to be highly adaptable to dryer and hotter environments (Castro, 2018).
H. undatus grows well in any well draining soil and prefers sandy, dryer, slightly acidic soil with a pH range between 5 and 7 (Tel-zur, 2015). The plant produces reproductive buds during the months of June through September, flowering for 30+ years (Castro, 2018). It was further observed that the flowering heavily relies on longer day length, requiring no less than 13 hours of daily sunlight and a high humidity between 60-80%, preferring a growth temperature of 30-32˚C (Castro, 2018). Important to note is the minimal requirement of rainfall needed for these plants to produce fruit is only approximately 1270mm of water per year, yet in some scenarios it can cope with less (Kishore, 2016). Dragon fruit can be grown from cuttings of a previous plant, or simply by extracting seeds that are found within the fruit itself. Attaining seeds from a seed bank may be a possibility. While fruit can take six to eight months to flower from seeds, dragon fruit once mature will subsequently have 4-6 fruiting cycles each year, bearing fruit for up to 30 years (Asmara, 2020). The number of viable seeds found within the plant is the most important determinant of fruit size and quality (Castro, 2018). This crop is naturally pollinated by moths, bats, and butterflies who are nocturnal pollinators (Tel-zur, 2015). Very little maintenance or tools are required to ensure the plant reaches optimum maturity aside from minimal pruning and possible trellis/climbing support structures to support the strong aerial roots that will grow rampant over the years. (Tel-zur, 2015; Kishore 2016). Regarding fertilization, field studies were conducted in Brazil throughout 2013-2016 that discovered potassium fertilization increased production and provided a better quality of pitaya fruits (Fernandes et al., 2018). Particularly, their studies demonstrated that K2O fertilization should be from 106 - 133.3 g K2O in the first year and 200 g K2O in the second and third years after planting (Fernandes et al., 2018). The fruit is preferably harvested at maturity which minimizes the incidence of chilling injury during cold storage, allowing the fruit to maintain desirable quality during marketing (Mustafa, 2018). However, relatively scarce information is available on the changes to the physiochemical properties of the fruit during cold storage (Mustafa, 2018). Being a tropical fruit, it has been assessed that the fruit is best stored between 14-20 ˚C and could become susceptible to chilling injury at 6 ˚C (Mustafa, 2018). The fruit at maturity is marketed or enjoyed by locals as is, or is often used in sorbets, can be dried at high temperatures and preserved for years if sealed properly in airtight containers at room temperature, or is even used as thickening agents or natural colourants in the food industry (Khuwijitjaru, 2018; Asmara, 2020). Due to its favourable qualities, dragon fruit holds high economic potential as an exotic crop in national/international markets with an unmet demand from hotels/restaurants globally (Hart, 2005; Kishore, 2016). The demand for dragon fruit internationally exceeds the supply, thus creating opportunities for smallholder farmers to commercially grow dragon fruit on larger scales and additionally to fill agri-tourism niches (Hart, 2005).
Benefits of Growing Dragonfruit
Here, I will examine how dragon fruit can be utilized as a channel of support for women smallholder farmers, as well as a successful and viable crop to combat climatic change. As already introduced, Hylocereus undatus remains an excellent option for climates that are increasingly getting warmer and dryer, due to its ability to store water in its stem, night-time opening of the stomata, CAM photosynthetic pathway, (Tel-zur, 2015; Castro, 2018). Dragon fruit requires very little equipment, resources or maintenance besides root climbing support and minor pruning to ensure high quality of fruit. Further, drying out of dragon fruit for preservation or to reduce post-harvest losses is a commonly used technique that requires little energy — an additional advantage for smallholder farmers (Khuwijitjaru, 2018; Asmara, 2020).
Research has shown how this species has been locally eaten by inhabitants of the Mayan region for years as a means to treat gastric and enteric diseases, for they have found this plant to hold nutraceutical health properties and anti-inflammatory characteristics (Mustafa, 2018; Kishore, 2016). Dragon fruit is rich in micronutrients and phytonutrients like Vitamin C, potassium, magnesium and calcium (Asmara, 2020). In these antioxidant and nutrient packed fruits, a typical 100 g serving will contain 3% of one’s recommended dietary intake (RDI) of vitamin C, 4% of iron and 10% magnesium - and additionally contains betalains, hydroxycinnamtes and flavonoids which are all antioxidants that help fight off chronic diseases ((Khuwijitjaru, 2018). Even the seeds of dragon fruit contain an oil that is found to have a high content of polyunsaturated fat acids, providing essential acids which are required by humans but cannot be naturally produced by our bodies (Khuwijitjaru, 2018). In terms of marketing and sales, it may be recommended for several women farmers in tropical, smallholder communities to join together into cooperatives to achieve an appropriate scale.
Critical Analysis of Growing Dragonfruit
Despite its economic potential, dragon fruit has received limited attention from the scientific community and until recently little was known regarding cultivation, optimal agro-techniques, flowering and pollination, pests and diseases, harvesting issues, etc. (Tel-zur, 2015). There are clear challenges that dragon fruit may pose to small scale farmers, including its susceptibility to chilling injury, radiation burning from sunlight as well as fungal infections (Tel-zur, 2015; Asmara, 2020; Hart, 2005). While more drought tolerant than citrus, dragon fruit still remains susceptible to burns from direct sunlight and therefore shade-nets may assist in increasing yields (Tel-zur, 2015). Chilling injury occurs around 6 ˚C posing a threat to its desirable colouring and quality during marketing, while different varieties of fungal infections may appear sticky on stems of over-matured fruit (Mustafa, 2018). Particularly, Dragon fruit are susceptible to multiple rotting diseases or scabs. Some of these key fungal infections include Anthracnose, Blight, Blotch, and different rots (Fernandes et al., 2018). Further, these diseases may develop during transport to markets, as storage is also concern for these fruits. In most tropical regions, dragon fruits are packed into 10 kg wooden crates, carefully placed as to not bruise or damage them during their travel (Fernandes et al., 2018). Alternatively, a preferred storage method with more ventilation for the fruits involves plastic crates that are more durable, easier to clean and re-use and reduce the risk of disease. The crates are more expensive, though in the long run they are durable with lower risk of disease.
In general, however, if women smallholder farmers were able to grow Hylocereus undatus, very few challenges and resources aside from common agricultural knowledge would be required in order for her to learn how to use this fruit as a channel of support for her and her family, and additionally as a means to combat climatic changes.
Links to Additional Resources
https://www-sciencedirect-com.subzero.lib.uoguelph.ca/science/article/pii/S0304423816305477?via%3Dihub —> Diagram of phenological growth stages of dragon fruit (Hylocereus undatus) according to the extended BBCH scale.
https://scholarspace.manoa.hawaii.edu/bitstream/10125/2403/FN-9.pdf —> Diagrams of propagation methods, and growing plantings.
https://www.youtube.com/watch?v=kgGNEJagk5U —> Time lapse of dragon fruit seeds germinating.
https://www.youtube.com/watch?v=P5uUzniBvAQ —> How to grow dragon fruit from cuttings of an established plant.
https://www.youtube.com/watch?v=UW2yS7uQ1zw —> Time lapse of dragon fruit bud to fruit.
https://www.youtube.com/watch?v=rg4efYvgmpw —> Easy pruning technique/demonstration to assist with propagating and proper growth.
https://www.youtube.com/watch?v=BMMfM3maMkE —> Video to describe how small scale women may start off growing dragon fruit in their backyard, very small scale - at home adaptable tips.
https://www.youtube.com/watch?v=eAY4OdcekWA —> Larger scale dragon fruit farms in Asia - shows from growing to sales production.
https://www.youtube.com/watch?v=1yEW5zUiheY —> Episode 1: Excellent video with all informative details on growing dragon fruit - small/large scale.
https://www.youtube.com/watch?v=LhOV8n-eBaM —> Episode 2: All facts about harvesting.
References
1. Asmara R., Dwiastuti R., Sakdiyah H., Ningsih K. (2020). Economic Valuation for Organic Farming of Dragon Fruit: Cost Benefit Analysis Approach. IOP Conference Series: Earth and Environmental Science, 469, 1-8. https://iopscience.iop.org/article 10.1088/1755-1315/469/1/012082
2. Castro, A., Lascurain-Rangel M., Gomez-Diaz J.A., Sosa V. (2018). Mayan Homegardens in Decline: The Case of the Pitahaya (Hylocereus undatus), a Vine Cactus With Edible Fruit. Tropical Conservation Science, 11, 1-10. https://journals.sagepub.com/doi/full/10.1177/1940082918808730
3. Fernandes, Denison Ramalho, Moreira, Rodrigo Amato, Cruz, Maria do Céu Monteiro da, Rabelo, Josimara Mendes, & Oliveira, Jéssica de. (2018). Improvement of production and fruit quality of pitayas with potassium fertilization. Acta Scientiarum. Agronomy, 40, e35290. Epub March 29, 2018. https://doi.org/10.4025/actasciagron.v40i1.35290.
4. Hart, G. (2005). From Prickly Pear to Dragon Fruit. Cactus and Succulent Journal, 77(6): 293-299. https://bioone-org.subzero.lib.uoguelph.ca/journals/cactus-and-succulent-journal/volume-77/issue-6/0007-9367(2005)77[293:FPPTDF]2.0.CO;2/FROM%20PRICKLY%20PEAR%20TO%20DRAGON%20FRUIT/10.2985/0007-9367(2005)77[293:FPPTDF]2.0.CO;2.full.
5. Khuwijitjaru P., Komonsing N., Nagle M., Mahayothee B., Muller J. (2018). Influence of drying conditions on colour, betacyanin content and antioxidant capacities in dried red‐fleshed dragon fruit. International Journal of Food Science & Technology, 54(2): 460-470. https://ifst.onlinelibrary.wiley.com/doi/abs/10.1111/ijfs.13958
6. Kishore, K. (2016). Phenological growth stages of dragon fruit (Hylocereus undatus) according to the extended BBCH-scale. Scientia Horticulturae, 213, 294-302. https://www.sciencedirect.com/science/article/abs/pii/S0304423816305477
7. Mustafa, A. M., Ali, A., Seymour G., Tucker G. (2018). Treatment of dragonfruit (Hylocereus polyrhizus) with salicylic acid and methyl jasmonate improves postharvest physico-chemical properties and antioxidant activity during cold storage. Scientia Horticulturae, 231(27): 89-96. https://www.sciencedirect.com/science/article/abs/pii/S0304423817305939
8. Tel-Zur, N. (2015). Research and Development of Pitahayas - Dragon Fruit - Vine Cacti: Limitations and Challenges and the Current Global Market. International Society for Horticultural Science, 1067(50): 365-370.
9. Tel-Zur, N. (2015). Pitahayas: Introduction, Agrotechniques & Breeding. International Society for Horticultural Science, 995(13): 109-115.
10. Zee, F., Yen C. R., Nishina, M. (2004). Pitaya (Dragon Fuit, Strawberry Pear). Co-operative Extension Service College of Tropical Agriculture and Human Resources, 9, 1-3.