Global fruit production is steadily increasing with the most increases of tropical fruits, such as pineapple, mango, papaya, litchi and dragon fruits. Tropical fruits are mainly produced by small-holder farmers in low- and middle-income countries and that helps farmers’ incomes and rural development.

Dragon fruits (Hyalocereus spp.) also named Pitaya and Pitahaya, originated from tropical America and currently distributed in tropical and subtropical America, Caribbean, Hawaii, Asia, Australia, Taiwan, Vietnam, Malaysia, Philippines and Israel. The fruit is a fleshy berry about 10-12 cm thick with red or yellow peel with scales and with or without spines. The pulp may be white, red or mixed white and red depending on the species. Seeds are very small, numerous and black, embedded within the pulp. The most noticeable functional bioactive compound in dragon fruits is the attractive deep red/purple pigment named batalain. It is an anti-oxidant, anti-inflammatory and natural colorant with great potential in food and processing industry. The small and edible seeds in the flesh contain omega-3 fatty acid which could enhance immune system and fight against diseases.

Dragon fruit production in Asia

Dragon fruit production and markets in Asia are fast growing for the past five years. Vietnam is the country with the largest area and production of dragon fruit in Asia and is also the leading dragon fruit exporter in the world. The area grown to dragon fruit is growing in Vietnam and increased rapidly from 5,512 ha in 2000 to 55,419 ha with a total output of about 1,074,242 tons in 2018.

Dragon fruit is popular in Taiwan in recent years due to its fast growth rate and great adaptability. The price also led more farmers to take part in its production. In 2016, the total cultivated area was 2,490 hectares with a production volume of 49,108 MTs and yield of 20 MT/ha. Red and white flesh varieties (ratio: 7/3) are current cultivated. The export volume in 2017 was 111 MTs, valued at US$311,770.

Dragon fruit is known as Mata Naga in Malaysia and is a minor crop, covering 695 ha mainly in Melaka and Johor in the south, producing 4401 MT in 2016 and 6,407 MT in 2017. In the Philippines, area planted to dragon fruit has been increasing in the past 10 years. Top production areas are mainly in Luzon and Central Visayas. In 2017, about 450 hectares were planted that produced 1463 MT of dragon fruit. Yield per hectare shows a positive trend from 1.41 to 3.25 MT. In selected plantations, yields of 10-15 MT/ha/year are possible for established plants that can be harvested 6-12 times per year.

Dragon fruit was introduced in India during the late 1990s. The cultivation is well suited in the agro-climatic regions of southern, western and north-eastern India that are dry and frost-free. The widely grown cultivar (white) is also the commonly seen in markets imported from Vietnam, Thailand, Malaysia, and Sri Lanka.

Pests and diseases

Dragon fruit canker caused by the fungus Neoscytalidium dimidiatum is the most destructive disease of dragon fruit in Asia. If not controlled, it has the potential to destroy dragon fruit orchards. Brown rot of dragon fruit caused by a fungus, Bipolaris cactivora, poses a serious disease risk of crop loss in the field and after harvest. The disease poses an extended serious threat to fruit export worldwide. Stem rot, anthracnose, and brown spot diseases are also common dragon fruit diseases. Fruit rot was serious at the postharvest stage. Chemical pesticide sprays to control diseased plants is commonly used in Asia. Dragon fruit anthracnose is mainly caused by Colletotrichum gloeosporioides. Different combinations of biological materials including plant extracts, bacterial and Streptomyces to control anthracnose in the field and glasshouse were tested.

Pest occurrences in dragon fruit during the plant growth and flowering stages, such as moths, thrips, aphids, and beetle pests, and during the fruit stage, such as fruit flies, mealybugs, stink bugs, beetles and snails. Most of the above pests have a direct or indirect relationship with ants, thus ant control is imperative. Effective management strategy including using low-toxic or pesticide-free pest control materials, applying area-wide integrated pest management (AW-IPM), early pest monitoring and prevention, and suppressing fruit fly population densities were recommended.

Dragon fruit is mainly propagated by cuttings and virus-infected mother plants can spread viruses via cuttings very easily. Cost-effective detection methods can be used for field survey and virus-free certification programs of mother stock and seedlings.

Postharvest handling and quarantine treatment

Cold storage prolongs fruit shelf-life and marketability. Improper postharvest handling and cold storage could cause fruit to appear dry and old, and can induce fungal diseases during and after cold storage. Precooling is the first and essential step right after harvest. Room cooling is a simple and common way to remove “field heat”. Forced-air cooling and hydrocooling are more effective. Packing: e. g. non-woven fabric with PE bag (24 holes with 0.8 cm diameter) can be used to avoid chilling injury. Active modified air packing (MAP) including bags sealed after flushing with 3% O2 and 5% CO2, followed by hypobaric and sealed packaging can maintain appearance quality after 19 days of 5°C storage. Container-based vapor heat treatment (VHT) for 2.5-3 hours can be applied as a quarantine treatment for export to Japan, to prevent proliferation of diseases and pests for DF export. VHT decreases disease occurrence, prolongs shelf-life, and does not significantly affect fruit maturation, taste and appearance.

International markets and challenges

Even though the overall production is continuously increasing, DF producers have seen prices of fruits decline since the product is mainly sold for local consumption or to neighboring countries. For example, retail prices in markets importing DF from Vietnam were USD 10-12/kg in the US and Australia, and USD 3.6-4.3/kg in China. Recent concerns over food safety, returns from pitaya could be significantly improved if small growers and exporters can gain access to new high value markets in Japan, Europe and North America.

Access to international high-end markets would enhance profitability, however several technical barriers and commercial challenges need to be resolved. Challenges with farmer awareness include fragmented DF farming areas, proper use of chemicals, access and use of cold chains and facilities to maintain quality, and proper postharvest handling. Commercial challenges include the fact that product output is not guaranteed, inability of demand to offer exclusive purchasing contracts with farmers, and limited capacity of small enterprises to create marketing plans and enter larger distribution channels.

Exports should try their best to assure product quality, even if there are many challenges ahead: unifying product quality standards throughout the country in accordance with Good Agricultural Practice (GAP) programs in place, international food hygiene and safety standards and, meanwhile, diversifying products from R&D of new varieties, processed food and promotion trade activities.

International sharing, learning and cooperation

Improved varieties with better adaptation of different growing conditions, disease resistance, good storage and processing properties, rich in nutrients and pleasant tastes and flavors would be competitive to meet requirements of diverse types of consumers and fast changing markets. Shuttle breeding, international cooperation, and joint efforts among DF breeders and researchers to accelerate the release of newly bred pitaya could be helpful approaches.

Highly perishable products, long transport distances and high production costs are significant challenges to the NZ horticulture industry. Nevertheless, horticulture is a major export earner for NZ and the country has a reputation as world leader in horticulture production and postharvest technologies. The evolution of Kiwifruit and Apple production systems in NZ and how these advances have been based on innovative research and the rapid adoption of new technologies by the industry could be shared and learned through international collaborations. In all cases intensification of planting has resulted in significantly high yields per unit of land area and remarkably high uniform fruit quality. Lessons learned in the development of the NZ horticultural export industry can be of value to Asian dragon fruit industries seeking to access the high value export markets in Europe and USA. Critical factors in New Zealand’s success have been a focus on consumer and market requirements for top quality produce, and increased production efficiencies to offset costs of inputs, labor, and transport.

Establishing food traceability system is a compulsory condition for exporting required by many countries. DFNet Partner from Vietnam shared the project of applying blockchain-based technology in building a traceability system for dragon fruits exporting to Australia. To support such a traceability system, the Australian Embassy, the Asia Foundation and the Institute of Policy and Strategy for Agriculture and Rural Development in Vietnam joined hands to establish a blockchain based identity and proof-of-provenance platform that allows tracing of a single dragon fruit back to an individual farm or farmer, as well as provide various information documenting the journey of dragon fruits from farms in Vietnam to importers in Australia.

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