The Real Reason Mangoes "Fall Before Ripening" ─ The "Stop" Signal Molecule Released by the Tree

"Fallen Mangoes = Ripe" is Actually a Dangerous Assumption

When you look up at the mango tree in your garden, you might see a green fruit drop. Even if you pick it up, the aroma is weak, and it doesn't ripen to sweetness — many people have likely experienced this.

In Australia's mango-producing regions, this isn't just a "disappointment at home." Every season, a large number of mangoes fall before ripening. Fallen fruits are hard to market, leading to income loss for farmers and food waste and resource wastage for society. According to the article, under certain conditions, only about 0.1% of the fruit reaches maturity. phys.org

Moreover, over 63,000 tons of mangoes are produced annually in Australia, making it a high-value crop that significantly contributes to the economy. News
Therefore, understanding "why they fall" and "how to prevent them from falling" is a theme that directly connects not only to farmers but also to food stability in the era of climate change. phys.org

The Key is "Stress" — Trees Shed Fruit to Survive

At the heart of the article is a rather blunt fact.
**For trees, fruit is a "luxury item"** and is the first to be cut when the environment becomes harsh.

For humans, it's like avoiding high-calorie indulgences when feeling unwell. Plants are the same; when stressed by heat, drought, strong winds, or leaf damage (from pests or defoliation), their internal balance shifts, and resource allocation leans towards "survival mode." phys.org

Here, plant hormones and the "sugar budget" become crucial.

• Plant Hormones: Chemical signals that regulate the growth of flowers and fruits, and fruit drop. Their concentration and reaction change under stress. phys.org

• Carbohydrates (Sugar): Fuel for growing fruit. If leaves are damaged or water is insufficient, they can't be produced or transported. phys.org

When the supply of sugar is disrupted, the tree decides "it can't grow them all" and drops the fruit to reduce the burden. The article explains that at this time, the hormonal balance is also disrupted, triggering the switch towards fruit drop. phys.org

Reading the Molecular "Quit Signal": The Stage is the "Pedicel"

Interestingly, researchers are not ending this phenomenon as merely "bad weather," but are viewing it as a molecular-level decision-making process.

The article describes that when stress disrupts the balance of sugar and hormones, the tree issues a molecular "resignation notice" to the fruit. Researchers call this the molecular "quit signal". phys.org

To decipher this signal, attention is focused on the pedicel, which connects the fruit and branch. This is a "communication bridge" where nutrients and signals pass, and simultaneously a control tower that regulates "detachment/retention." The research aims to analyze the gene expression in this pedicel tissue (which genes are turned ON/OFF) to identify the pathways that trigger fruit drop. phys.org

In other words, the aim is not to
"guess the cause after the fall," but to
identify the "signal" before the fall and create a state where intervention is possible.

Promising Countermeasure: Plant Growth Regulators (However, "Timing" is Crucial)

So, what are the means of intervention?

The article highlights as "promising" the use of Plant Growth Regulators (PGR). These are agents that supplement or adjust the function of plant hormones, aiming to maintain fruit even under stress. phys.org

Here, the point was not so much about whether it works or not, but about timing.

• It was more effective to treat at an early stage during the flowering period (before the fruit is fully developed)

• As a result, in initial trials, yields increased by up to 17% phys.org

The article describes this early intervention as akin to a "hormonal pep talk" for the tree. phys.org
Strengthening the retention signal before the tree leans towards the decision to "have to drop" — it's a very rational concept.

However, there is an important caveat.
This research is still pre-peer review, and it is planned to be published after further verification of seasonal, varietal, and regional differences. phys.org
It's important not to jump to conclusions that a "universal prescription has been found" immediately.

Why This Matters Now: It's Not Just a Mango Problem

The scope indicated by the article is not limited to the field of mango cultivation.
Early fruit drop occurs in other fruit trees like apples, citrus, and avocados, with hormone imbalance due to stress as the underlying cause. Therefore, understanding the "molecular switch of fruit drop" in mangoes could potentially be applied to other crops. phys.org

In an era where climate is unpredictable, agriculture is entering a phase where "experience and intuition" alone are not enough to succeed.
Visualizing what's happening inside plants and taking action at the right time is the essence of "precision agriculture."

Social Media Reactions: Empathy and Practical Questions Emerge Rapidly

In connection with this article (originating from The Conversation and introduced on Phys.org, etc.), three main types of reactions are noticeable on social media.

1) Home Gardeners: "My Mangoes Also Fall. What Should I Do?"

On Facebook, posts sharing the article have received quite earnest inquiries like "They always fall before maturing. There's sunlight and rain, so why?" Facebook

In another post, questions like "Why do immature mangoes keep falling?" are noticeable, indicating that it's a common issue even at the household level. Facebook

This article resonates because, while it's a scientific discussion, it's a theme many people are currently struggling with.

2) Agriculture and Food Waste Context: "Science to Reduce Waste is Justice"

On LinkedIn, posts from those in the food and agriculture sectors positively introduce the article as "science to reduce waste in cultivation fields." linkedin.com
Because it directly connects to the social theme of "reducing food waste," the significance of the research is easily conveyed.

3) Spread Accounts: "This is Something Everyone Wants to Know"

On X (formerly Twitter), posts quoting and spreading the key points of the article can be confirmed (at least shared in a form that excerpts the beginning of the text). X (formerly Twitter)

On social media, topics that combine "everyday mysteries" with scientific explanations are strong and naturally spread easily.

Note: Due to viewing and acquisition restrictions, we could not confirm a large amount of "comment section discussions" on social media. Therefore, the above is organized based on the range of posts and reactions that could be confirmed. linkedin.com

Looking Ahead: From "Falling Fruit" to "Resilient Fruit"?

The future depicted in the article is not about flashy genetic modifications or "super varieties."
It's about understanding the mechanism by which trees drop fruit and increasing retention rates with minimal intervention, timed with periods of increased stress. . phys.org

If pre-mature fruit drop decreases, farmers' incomes stabilize, consumers can access affordable fruits, and society as a whole reduces resource waste. As climate change progresses, "not dropping" becomes not a luxury but a strategy to protect the food base.

Whether mangoes will "hold on" to the tree next season.
The battle begins quietly, not at the branch tips, but deep within the pedicel. ##HTML