Why mangoes bear fruits all year-round now

Wherever you go now in the Philippines, you can see stalls selling mangoes along the road. (Henrylito D. Tacio)

By Henrylito D. Tacio


By Henrylito D. Tacio

Michael Bassey Johnson, the man behind The Book of Maxims, Poems and Anecdotes, has written something about mango, the Philippines’ fruit icon. “If you wait for the mango fruits to fall, you’d be wasting your time while others are learning how to climb the tree.”

Israelmore Ayivor, author of 101 Keys to Everyday Passion, also reminded, “Don’t sit at home and wait for the mango tree to bring mangoes to you wherever you are. It won’t happen.”

When it comes to mango, Philippine mangoes are the number one. In fact, former Agriculture Secretary Leonardo Q. Montemayor said a local variety has found its way to the Guinness Book of World Records as “the sweetest of its kind in the world.”

Wherever you go now in the Philippines, you can see stalls selling mangoes along the road. (Henrylito D. Tacio)

Although mango is the country’s fruit icon, it is not endemic to the Philippines. History records showed that mangoes originated from the Myanmar region, where it was known to have been cultivated 4,000 years ago. Buddhist monks took the mango to Malaya and eastern Asia in the 5th century B.C. 

In the 18th century, Portuguese explorers would introduce mango in Brazil. From there, mango cultivation would reach Florida, United States in 1833 and eventually Africa and  other lowland tropical and subtropical areas. Today, there are about 83 mango-producing countries in the world. 

There are several varieties of mango grown in the Philippines, but when people talk about the fruit, they are actually referring to mango carabao. The fruit is elongated and kidney-shaped, weighs about 240 grams, with thin, yellow pulp, very tender taste, and a slight aroma.

Before 1974, mangoes were available for a short period of time only, specifically during the summer months. “Despite the superior taste of mangoes, and despite having been around since six centuries ago, they remained virtually a commercially neglected fruit that raised little revenue,” observed Dr. Ramon C. Barba, the man who invented a way to induce more flowers in mango trees and was named national scientist in 2014. “This lowly status was largely because mango has unreliable fruiting habits.”

In those years, the fruit habits of mangoes were seasonal, biennial, and erratic. Dr. Barba, whose academic background is agronomy and fruit production, reported: “If (mangoes) bear fruit one year, they may not do so the next year. Usually, mango trees bear fruit for only one month in a year. Yield may vary from year to year, from tree to tree in a grove, and even from branch to branch in a tree.”

These unreliable fruit habits of mangoes were the reason why investors were not so keen in engaging in mango production. “A requirement for economic stability of any fruit industry is regular production, which means active control of flowering and fruiting,” Dr. Barba recalled in his Dr. D.L. Umali Lecture, “Revolutionizing Agricultural Science and Farming Technology: Chemical Flower Induction of Mango.” 

“Controlled flowering,” he continued, “is ideal to produce out of season crop, to increase production during the normal flowering season, or to offset its biennial, erratic, and sparse fruit bearing habits.”

To solve the problem, farmers at that time resorted to the ancient and unique practice of smudging. It is the process of building a smoky fire beneath the tree, and then allowing the dense smoke to pass through the foliage continuously for 20 days. This process helped advance the bearing of fruit in about a month.

“Smudging is cumbersome, slow, costly, and unreliable,” Dr. Barba remarked of the folk practice.  “Overall, smudging as a technology did not propel the mango fruit crop to commercial prominence.”

However, he observed that the ethylene in smoke produces the flowering effect; since ethylene is a gas, the mango tree would then have to be covered in order to get the best results from smudging. This gave him the idea believing there was a better, more efficient and economical way than smudging to induce flowering in mangoes.

That was what he did. As Assistant Professor at the Fruit Crops Section Department of Agronomy at the University of the Philippines College of Agriculture, he considered the possible use of synthetic growth regulator Ethrel on mango.  

But research was already conducted on it. When he reviewed the result of the study, he found out that using high concentrations of Ethrel in mango causes defoliation. In low concentration, however, the success rate of flower induction was reduced.  

When his request to further conduct experiments on it, he was turned down. So, he decided to conduct private experiments at the Quimara Farms in San Jose del Monte in Bulacan, where he served as farm consultant. He was asked to rehabilitate the 500 mango trees planted which were 10 years old, not over 15 feet high, and had not yet attained the flowering stage.

“(The mango trees) appeared stunted and with no sign of flowering at an age when flowering should have started,” he recalled. “The owners allowed me free use of their farm for experimentation.”

Dr. Barba tried some chemicals until he settled for potassium nitrate (KNO3) which, without his knowledge, was already used as a direct agent to induce flowering of any plant. “I found out that KNO3 at 1% aqueous solution was effective as a spray to induce flowering in mango,” he recalled. “Lower concentrations were not as effective, while higher concentrations were wasteful and may injure the shoots. Bulging of normal shoots was observed after one week, and flowers appeared during the second week.”

He was ecstatic with the result. “In early January 1970, I sprayed one hundred trees with the same solution used in the first experiment I conducted barely two weeks earlier in order to verify the initial results,” he said. “I dissolved one kilogram of KNO3 in 100 liters of water and sprayed the solution as a drenching spray on the mango trees. In one week. Buds began to form; in two weeks, the buds were developing into flowers; and after four months, fruits reached maturity and were ready for harvesting.”

It was just a matter of time that mango production would become a money-making venture. “Mango is now on its way to becoming a major tropical and subtropical high-value fruit commodity,” Dr. Barba predicted. “This would not have been conceivable if the KNO3 flower induction technology was not in place to provide a regular and steady supply of mango for the local and international market.”

When the technology was made public in 1974, it was held as a breakthrough. In A Guide to Mangoes in Florida, author R.J. Campbell noted: “Sometimes ago, researchers discovered that they could induce good mango flowering in areas where it normally was poor by spraying the leaves with a solution of potassium nitrate. This discovery stimulated investigators in many countries on flower induction of mango… Control of flowering is a topic of great interest and an area receiving considerable research attention throughout the world.”

In 1978, the prestigious Reader’s Digest also hailed the discovery: “One of the pioneers is the Philippines…  Scientists at the Los Baños College of Agriculture have found that potassium nitrate sprayed in mangoes at 1 percent concentration induces the trees to flower early and profusely…  Mango, until recently, was, for most, an exotic name in travel books. Now, the mango is enjoyed all over the world, and is likely to become the king of tropical fruit.”

Dr. Barba’s discovery went unnoticed until 2008, when the Switzerland-based World Intellectual Property Organization (WIPO) recognized the mango flower induction technology through a short documentary film that promotes intellectual property. It was the first time that a country from Asia and the Pacific Region was included in the WIPO documentaries.

As a scientist, “his other research breakthroughs include banana micropropagation and tissue culture of sugarcane and tissue culture of calamansi, all of which have left lasting impacts on the respective agribusiness potentials of these commodities.”

In 2001, Dr. Barba told a local newspaper that farmers should not spray their mangoes with too much flower inducer because “it is bad for mangoes.”

In 2011, he was honored with the D.L. Umali Award. The citation reads in part: “As a scientist, Dr. Barba’s philosophy hinges on the continuous search for new frontiers. He uses his imagination to discover a possible new direction, and to take the bold and untried steps to discovery by relying on the rich store of knowledge that has come his way. 

Dr. Barba died on October 10, 2021 at the age of 82.

Thanks to Dr. Barba, mangoes can now be eaten all-year round. Mango tops as the most favorite tropical fruit in the Philippines. This was based on the survey conducted by this author. More than 50% of the 70 respondents interviewed via e-mail and text messaging have chosen mango as the fruit of all seasons.

By spraying mangoes with flower inducer, mango fruits can now be harvested throughout the year (Henrylito D. Tacio)

Dr. Marimel Yap-Veloso, consultant ophthalmologist at the Asian Eye Institute in Makati City, reasons out: “Mango is sweet and satisfying – and it has great texture, too! It’s great on cakes, pies and as a juice or shake. It’s a versatile fruit. The green variety is also delicious with fish and bagoong.”

Lionel Tierra, a Filipino who now lives in California, prefers ripe mango. “It is succulent, sweet and heavenly to the taste,” he wrote. “I’ve tried durian, star apple, and atis, among others – they are all very good to taste, but mango, to me, is still the best. Mango is like my best friend and sweetheart.  All other fruits are just good friends and acquaintances.”

Larry Stoffel, an American who is married to a Filipino, confirmed this. “The rich juicy flavored mango from the Philippines is the most fantastic fruit I have ever tasted,” he revealed. “It’s true that we import mangoes from other countries but those imports cannot duplicate the mangoes I have eaten in Bohol. I miss the mangoes and can’t wait until I can have some more when I go back there.”

Now wonder there is a sure market for mangoes, according to the Agribusiness and Marketing Assistance Division (AMAD) in Davao Region. Around 93 percent of the country’s mango supply is consumed locally.  Of this proportion, it is estimated that 75 percent are eaten as fresh fruit and 25 percent are processed into various product forms.

The Philippines is one of the world’s leading mango producers and exporters. Karina Fernandez-Stark, Vivian Couto and Gary Gereffi, authors of “The Philippines in the Mango Global Value Chain,” pointed out: “The Philippines holds a relatively significant position in the mango global value chain (GVC).”

The country has been an important player in the global market since the 1980, with exports taking off in the 1990s.  “Leading processors have been steadily gaining access to regional and global markets,” the three authors wrote in their paper.

In 2021, the total volume of mango exported from the Philippines amounted to around 10.08 metric tons, according to The total value of exported mangoes amounted to around P617.8 million.

The Rome-based Food and Agriculture Organization (FAO) of the United Nations said the Philippines accounts for an average of 10% of the world’s fresh and dried mango exports. The major export destinations were the United States, Hong Kong, South Korea, and Japan.

Among its other foreign markets are Australia, Singapore, and some European countries (Belgium, Germany, Hungary, Ireland, Finland, Poland, Italy, the Netherlands, and the United Kingdom).

Most mango exports come from Guimaras Island, particularly those that go to Australia and the United States. In 1993, the National Mango Research and Development Center in Guimaras was established as the center for research and development of the mango industry.

Mangoes can now be sold anytime of the year (Henrylito D. Tacio)

Most of those who have tasted the mangoes from Guimaras said that the fruit tastes differently from mangoes in other parts of the country or anywhere else in the world.

One blogger wrote: “Guimaras is located in the Western Visayas region, where the climate is not as humid as the other areas of the country. The location as well as the climate directly affects the quality of any fruits. Moreover, the soil where these trees are planted is very rich in nutrients which help the trees to bear fruits that are rich in flavor and nutrition.”

 Next to banana and pineapple, mango is the third most important fruit crop of the country based on export volume and value.

Photos by Henrylito D. Tacio

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