Leo Skliros, President of the Mango Industry Association of Northern Australia, has the ability to help mango trees flower and bear fruit early in winter (July).
Like all countries in the Southern Hemisphere, the seasons in Australia are opposite to those in the Northern Hemisphere. December to February is summer, March to May is autumn, June to August is winter, and September to November is spring.
Skliros grows Kensington Pride mangoes— a variety highly favored in Australia for its sweet, juicy flesh, but with inconsistent growth. So how did he manage to get mangoes to bear fruit in July, when this variety typically harvests at the end of September?
Kensington Pride mangoes are popular in Australia for their sweet, juicy flesh, but they have inconsistent growth. (Photo: ABC).
Skliros explains: “It’s a bit like KFC. The dish with ‘eleven herbs and spices’ is a secret recipe, and there’s a lot involved.” But if you dig a little deeper, the recipe isn’t entirely a mystery.”
“Many growers have what they believe is their own secret recipe, but it’s just variations of what growers do around the world,” he says.
“It’s all about timing. You need to be in the right place at the right time.” Skliros analyzes, adding that everything a mango grower does can affect the outcome, but the timing of fertilization and pruning is crucial. This process is quite complex, but Skliros reveals that some fertilizers are used to reduce nitrogen and increase calcium levels, and when the weather is cooler, potassium nitrate can be sprayed to encourage mango flowering.
Tim Elliott from Red Rich Fruits states that the timing of fertilization is also influenced by lunar cycles, atmospheric pressure, and thermal density, factors that can make a difference between flowering or leafing.
Other variables to consider include location—especially in areas with changing microclimates—along with water, biosecurity, and plant health. A tree must have enough energy to flower, hold flowers, and set quality fruit.
Surprisingly, Elliott mentions that some trees thrive in rocky mountainous regions. Unable to be taken outdoors for planting, growers can have more control over nutrient timing with fertilizers, and thus the trees will flower.
“Now, all these factors can contribute to early fruiting or later fruiting depending on the purpose,” Elliott affirms.
According to Elliott, some farmers use a method of branch cutting (ring-barking) to encourage flowering, although this can affect the health of the tree.
Skliros, on the other hand, refers to a different strategy: tree pruning. In addition to using machines, this involves chemicals targeting the roots and keeping the tree size manageable so that they do not grow too fast, too tall, or too vigorously.
Insects are another important variable. Insects include both beneficial and harmful types. Sometimes, pesticides are used if pests break out, especially when buds begin to bloom. Then, important pollinating insects come in and do the pollination work once the tree has flowered.
Researchers have found that flies tend to be the most significant pollinators on mango trees, followed by various species of bees, beetles, ants, butterflies, and moths. With this information, Elliott says that trialing growers need to find what works best for them, with some quite creative results.
“I visited one grower who used to work on a fishing boat,” he says. This grower hung barramundi fish carcasses on a second tree, attracting flies and providing excellent pollination.
The process of getting mangoes to fruit early involves a lot of experimentation, mistakes, and learning how to understand the mango tree. “There are many ways people have figured out to make trees flower,” Elliott explains. “So, if applied, instead of one flower, growers can produce hundreds of flowers blooming early.”
Encouraging mangoes to fruit early has created a niche market for Australian mango growers. However, will these tricks and techniques make winter mangoes, which can fetch up to $70 per tray in premium fruit shops, more accessible in the future?
Elliott hopes not. “Early mangoes should always be a luxury item,” he concludes.
