Bananas, known for their distinct shape and color, are often likened to crescent moons due to their curvature. While there's a common misconception that bananas curve towards the sun as they grow, scientific evidence suggests otherwise, pointing to a biological explanation for their shape.
Negative Geotropism: The Curvature of Bananas Explained
When bananas are in their early stages, they initially grow straight downward toward the ground. However, as they mature and increase in size, they start to bend upwards, seeking sunlight for sustenance. This natural phenomenon, known as negative geotropism, is what causes bananas to curve.
Negative geotropism prompts the banana to flex upward during its growth process. This is driven by the presence of auxin, a plant hormone that influences how the plant responds to sunlight.
This bending occurs as the banana adapts its growth pattern to move toward the sunlight, effectively folding against its weight. In essence, geotropism, in this case, refers to the plant's growth pattern concerning gravity, where bananas tend to grow away from gravity and towards the sun, hence the term "negative geotropism."
Dole, the global food company responsible for banana distribution, elaborates on their website about the development of bananas from banana flowers, which emerge as buds from the pseudostem, the sturdy central trunk of the plant. Under each petal of the flower, a series of small banana fruits begin to take shape.
As these fruits grow larger, they undergo negative geotropism, redirecting their growth trajectory towards the sunlight rather than continuing their downward path. This upward growth is crucial for bananas growing in rainforests, where sunlight is scarce, and the sideways penetration of light through the dense vegetation is limited.
By reaching upward towards the breaks in the canopy where sunlight filters through, bananas mitigate the risk of toppling over due to imbalanced growth. If bananas were to grow solely towards the limited sunlight that penetrates sideways through the foliage, the plant could become unstable and prone to toppling over.
Therefore, bananas adapt by growing upwards towards the openings in the canopy where sunlight is more readily available. This evolutionary response ensures the banana plant's stability and optimal exposure to sunlight for photosynthesis, essential for its growth and development.
Are There Straight Bananas?
Bananas were first cultivated in South Asia and New Guinea before reaching Europe around CE 300. By the 1800s, selective breeding had resulted in the familiar long and curved appearance of bananas consumed today.
Further selective cultivation occurred in the 1900s, as large-scale plantations, managed by major distribution companies, prioritized bananas with uniform appearance, taste, and disease resistance.
The curved variety of bananas predominates among the numerous types of this fruit, which exceed 1000 in variety, showcasing diverse colors, sizes, and shapes. Naturally occurring organic bananas often exhibit green or brown hues, with a shorter and bulkier appearance and minimal curvature.
In 2022, Fairtrade introduced the world's first upright banana, facilitating consumers in making sustainable choices by promoting this innovative variety.
The creation of the upright banana stemmed from a collaborative effort between Fairtrade, AgroFair, and farmers from the Plátano Recto cooperative in Colombia, implementing a unique method to support the truss stem, enabling bananas to grow straight and addressing the tendency of standard bananas to curve due to gravity.
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