Opinion Piece by Mike Prociv, I have shared this as interesting seeing other peoples opinions on the dragon fruit growing industry.
You may agree or disagree, or just learning something new from another persons opinion.
Mike is the creator of MPH Variety.
Advice to any person wanting to grow Dragon Fruit for the first time.
There are around a dozen species of climbing cactus that produce commercial quality, edible fruits. These have been cultivated and traded by Central American people for thousands of years, but they have only come to the attention of Western people as a commercial food crop, about 40 years ago. In the last decade, global interest in these fruits has increased at phenomenal rate. Many people have taken advantage of this trend as an easy way to make money through the sale of plant cuttings.
Generally, people around the world have an expectation that when they purchase one fruit tree, that single tree will produce fruit by itself and without any interference from people. Of course, there are some species that require a male tree and a female tree in order to set fruit.
The wild species, collectively called pitaya or dragon fruit, generally are self-sterile, that is, the flowers will not accept their own pollen – they cannot set fruit by themselves. In order to set fruit, they must be pollinated using pollen from another plant. In the natural environment, night active blossom bats and moths transfer the pollen from flower to flower thus performing the pollination process that sets the fruit. Cuttings from these plants have translocated across the globe to sites where there are no natural pollinators, or where insufficient genetic variations occurs within a close distance. Here, people must hand pollinate each flower in order to set fruit. This entails growing more than one variety, then, if they flower synchronously (the flowers only open for one night and no one can predict which nights they will open), take pollen from one variety to pollinate the other variety.
As more people experiment with breeding, thousands of new cultivars are emerging. There are now dragon fruits that express, along a sliding scale, the following attributes: flavours and flesh textures; fruit size, shape and weight; thorny skin or smooth skin with no scales to long scales; green, yellow, pink, red and maroon skin; white, pink, red and magenta flesh. Breeders have developed many excellent quality varieties with highly improved flavour and sugar content that are also self-fertile – that is, a single plant will self-pollinate and set fruit by itself. These improved, self-pollinating varieties have now made the self-sterile varieties redundant.
The original self-sterile white pitaya was brought into Australia over 100 years ago. People have grown them for their ornamental night flowering, never knowing that they produced fruit. Today there are daily web postings for the sale, or free give-away, of dragon fruit cuttings that must be hand pollinated, but rarely is that highlighted. Many people are now wanting to grow their own dragon fruit yet know nothing about them. Would you sell or gift a self-sterile dragon fruit cutting or seed, to a person knowing that they will need to regularly monitor the flowering, know what night the flower will be open, go out between 9-10pm to harvest the pollen, then store some in the fridge or immediately pollinate flowers of another variety. If they missed a flowering, there won’t be any fruit set. That will be the situation for the life of the plant. This explains why there are so many daily social media posts asking: “why are my flowers turning yellow and dropping off; why aren’t I getting any fruit?” Why go through all of that when you can grow one self-pollinating plant that will give you fruit without you doing anything?
What is the take home message: If you want to grow dragon fruit plants for its fruit, then only obtain a guaranteed self-pollinating variety. If it can’t be guaranteed, don’t accept it, even if it is for free. Many of these sellers have a “buyer beware” policy, so ask the question and be sure.
Background – what is Dragon Fruit?
There are currently about 13 identified species of climbing cactus plants in the genus Hylocereus inhabiting Central America from Mexico to Brazil. They inhabit a range of environments from coastal lowlands to lower altitude ranges encompassing tropical rainforests, seasonally wet woodlands and dryer savannahs. Being climbers, they grow up and over things to reach full sunlight. They will only flower in full sun and only on branches that are suspended downwards. Typically, in many plant groups and Hylocereus is no exception, individual plant flowers do not accept their own pollen. This is an evolutionary trait to prevent inbreeding. So, they are totally dependent upon animal pollinators to transfer pollen from one plant to another plant to achieve seed set via the production of a fruit. The flowers are notoriously large meaning that they had evolved to attract large pollinators such as nectivorous bats, monkeys and other mammals such as rats etc. Insects are attracted to the flowers in large numbers but their role in cross-pollination is doubtful. You can image one bee enters a flower the size of a dinner plate with hundreds of stamens containing pollen many times larger than the mass of the bee. The bee can completely fill up in one flower and return to the hive without visiting another flower. (Bees do pollinate self-fertile flowers but that is a story for another time).
Now, all of the members of this Hylocereus genera can cross-pollinate all the other members and each can produce fertile offspring from these crossings. (The spiny yellow fruited pitaya was described as Selenicereus megalanthus, but some years ago it had a name change to Hylocereus megalanthus). The definition of a “species” is: “a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g., Homo sapiens”. Arguably, all of these members of the Hylocereus genera are just one species and what are now described as species are most likely sub-species or varieties.
Throw into this mix the human influence. The Aztecs, Mayans and Incas held vast civilizations over thousands of years throughout the natural range of the Hylocereus group, a plant they referred to as “pitaya” or “pitahaya”. These civilizations constructed vast road networks linking cities and villages. Food plants were transported and traded across this entire area and pitayas were grown as garden food plants in practically every village. With so many pitaya plants being transported vast distances over a long period of time, it is natural that there would be a lot of cross-pollination between varieties and seeds would have naturally germinated and emerged demonstrating a variety of new traits. The plants showing new desirable traits were favoured and traded with neighbouring villages. Over time, new varieties emerged from this process.
Just to complicate things more, pitaya plants are not consistent in how they present. Every aspect of a life form is governed by its genetics. Each individual pitaya plant has its own unique genetic code – each plant is different in the same way you are different from the other members of your family. When one pollen grain (male) fuses with one ovary cell (female) a seed is formed. One pitaya fruit can contain 2000+ seeds – each seed has its own unique genetic code. Some genes are dominant e.g., those responsible for producing thorns, so they override the recessive genes for smooth skin. Some genes are co-dominant, so the result is a mix of both genes eg red flesh X white flesh gives pink flesh (in some cases). These can be measured and are predictable. Genes also have an unpredictable characteristic of being switched on or off. Environmental factors can trigger these “switches”. For example, the Israelis’ developed a variety by crossing spiny yellow with a red, resulting in what they named “Desert King”. Other than the thorny skin inherited from the yellow, the fruit was the right size, the right colour and sweet. It was exported to the European market. Years later someone decided to establish a Desert King farm in Hawaii. Desert King was developed in the Negev Desert with its freezing winters, blistering summers with low humidity. These environmental conditions triggered the genes to express themselves in the form that produced that desirable Desert king fruit. Take that same plant to a milder, wet and humid location and different genes are triggered to express the fruit in a different way. The first crop was inedible and as a consequence, the entire orchard was ripped out.
Pitaya (white Hylocereus undatus) was introduced into Vietnam by the French colonialist well over 100 years ago. These were plants that were not self-pollinating. Eventually varieties emerged through mutations and they developed an industry on their very large, smooth, pink skinned, but bland variety. To establish the industry, a marketing ploy invented a mythological story of the “Dragon Fruit” which launched pitaya onto the world market under that invented name.
Interestingly, pitaya also landed in Australia around 100 years ago as an ornamental plant known as “Orchid Cactus” or “Lady of the Night”, favoured for its magnificent night floral displays. People in Cairns had them all their lives, growing right to the tops of tall coconut trees and never realising that they were dragon fruit because they never produced fruit – they were not self-fertile.
This often answers the common questions – “why isn’t my dragon fruit plant producing fruit?” and “why are the flowers turning yellow and dropping off?”
Australians’ first introduction to pitaya were some of the poorest examples of the fruit. Once tried, people did not want to try it again. The attitude developed that white was not worth eating. It is going to take a lot of education and promotion to change these first perceptions. Some of the tastiest fruit I have enjoyed were white fleshed – they do exist.
The other most commonly asked question relates to the design of trellises. It is difficult for a newby having received a cutting, to imagine what size it might grow to. The below photo shows a pitaya plant that has gone feral opposite the Cairns airport. It consumes an entire 30m high rainforest emergent tree as well as every understory shrub and rock for an acre beneath the tree. You can see closed yellow flowers on the suspended branches, yet no fruit set.