By Russell T. Nagata
By Russell T. Nagata
University of Hawaii at Manoa
College of Tropical Agriculture and Human Resources
Komohana Research and Extension Center, Hilo
The banana has been a part of Hawaiian gardens since the first Polynesians settled these islands. By most accounts, the early Polynesians brought three or four banana varieties to Hawaii, all of them starchy to semisweet in taste.
The remaining Hawaiian banana varieties are thought to have originated by mutations of the original introductions in a process called sport mutations. Sport mutations are naturally occurring changes in the genetic makeup of a plant and when selected and propagated will lead to a new variety.
Many new varieties of apples and citrus arose from the process of sport mutation. A recent sport mutation of banana in Hawaii has been the “hurricane” variety of dwarf apple banana reported on Maui. The name represents the larger trunk diameter of the sport mutation selection, thus giving it more resistance from toppling over in high winds.
Since the 18th century, with the discovery of the islands by Western civilizations, many other varieties, including sweet varieties of bananas, have been introduced into Hawaii and provided us with a diversity of fruit flavors, texture and color.
Hawaii was once a major producer of bananas for export to the mainland United States. At its peak export market around 1915, Hawaii shipped over 10 million pounds of banana out of a total production of over 16 million pounds. Worldwide competition and local fruit fly infestations led to the decline and extinction of the export industry.
Currently, Hawaii imports nearly 20 million pounds of bananas and commercially produces another 17 million pounds of fruit. Untold numbers of backyard fruit are also produced and can easily add an additional million pounds or more of fruit. Ten thousand households producing 100 pounds of banana would do it!
Have you given much thought to what the perfect banana would be like?
If you think of bananas as a single-dimension fruit, you have not paid attention or experienced the different flavor, texture and sweetness (or lack of) that bananas can provide. While some of you certainly grow varieties of banana based on your preference, many eat what is available for purchase.
Knowing that bananas have unique varietal characteristics can enhance your love of one of the perfect fruits in Hawaii. While choice may have a lot has to do with the intended purpose of the banana, time devotion to maintenance of the plant and personal taste, how do we select the perfect banana?
When researching the acquisition of bananas, you may have come across a capital “A” and/or “B” letter designation after the variety name and may have wondered whether these were letter grades on quality factors, as with pearls. While some would live up to the designation of “AAA,” as in Williams or Chinese varieties, one of the most beloved bananas — the Brazilian or, as locals refer to it, the apple banana — is “AAB.”
In actuality, the banana has a complex parentage and genetic makeup, being born from either of two parents or its hybrid. The two parental species are Musa acuminate and Musa balbisiana and are designated by the capital letters “A” and “B,” respectively. The genome can be diploid (two sets of chromosome, like humans), triploid (having three sets of chromosomes) or tetraploid and can contain one or both parental types.
Many diploid banana varieties are seeded, containing numerous pea-sized black or brown seeds, making them unfit for casual eating. While seedless diploid varieties are known, these are rare and seldom grown in Hawaii. The genetic makeup of the banana you grow will affect taste, texture, plant appearance and other characteristics. Knowing the characteristics that each parent imparts upon the progeny will give you insight into what the fruit and plant characteristics will be like.
Plants with “A” genome (“AA” and “AAA”) are sweet and soft, like the Williams or Chinese varieties, or often referred to as store or supermarket type bananas. “A” type plants in general require more water and care. They are more susceptible to banana bunchy top virus infection and, when infected, will not fruit. The “B” genome (“BB”) is less sweet, firm and starchy. The hybrids (“AB,” “AAB” and “ABB”) are a mixture of the two parents, and their characteristics reflect the percentage of each parent and range widely in taste and texture.
As a note: All sweet-apple tartness bananas are “AAB,” which is represented by our local favorite “apple banana.” Also, many of the original Hawaiian varieties are also “AAB” bananas. For a more in-depth knowledge on bananas, you can read the Angela Kay Kepler and Francis G. Rust book: “The World of Bananas in Hawaii: Then and Now.”
Next week I will cover, or uncover, a possible case of mistaken identity of one of Hawaii’s most beloved bananas, the “apple.”
For more information on this and other gardening topics, please visit the CTAHR electronic publication website at http://www.ctahr.hawaii.edu/Site/Info.aspx or visit any of the local Cooperative Extension Service offices around the island. I can be reached at russelln@hawaii.edu.