All About Bananas

Banana Basics

• Bananas, botanically known as Musa acuminata, belong to the Musaceae family.
• A banana is an edible fruit from large herbaceous flowering plants in the genus Musa.
• In some regions, cooking bananas are known as plantains.
• Banana fruit exhibits variations in size, color, and firmness.
• Bananas are usually elongated and curved with a soft, starchy flesh
• The rind, which covers the fruit, can be green, yellow, red, purple, or brown depending on ripeness.
• Fruits grow in clusters from the top of the plant.
• Modern edible seedless bananas derive from two wild species: Musa acuminata and Musa balbisiana.
• Bananas are believed to have originated in Malaysia approximately 4,000 years ago.
• Alexander the Great's army documented bananas circa 327 BC.
• Banana clusters contain 50-150 fruits, divided into 10-25 bunches called "hands".
• Roughly 50 species exist within the Musa genus, encompassing both bananas and plantains.

Cultivation and Consumption

• Bananas (Musa spp.) thrive as a tropical crop in wet regions such as Africa, the Americas, South and Southeast Asia, and the Pacific Islands.
• About 87% of bananas are consumed locally, with the remainder distributed beyond tropical areas.
• Bananas have undergone cultivation and hybridization for thousands of years.
• Edible bananas are hybrids of Musa acuminata (diploid) or M. acuminata crossed with M. balbisiana (triploid).
• M. acuminata is found throughout Southeast Asia.
• M. balbisiana is mainly in mainland Southeast Asia.
• Domestication of M. acuminata led to seed suppression and parthenocarpy, enabling cultivation without fertilization.

Economic and Nutritional Aspects

• Bananas are a popular fruit in America.
• Bananas can be eaten raw or used in chips, ice cream sundaes, oatmeal, pancakes, and cereal.
• The BRAT diet (Bananas, Rice, Applesauce, Toast) includes bananas for those with diarrhea or upset stomachs.
• Bananas contain potassium, which regulates fluid balance, and fiber, which aids digestion.
• Plantains, a larger, green banana variant, are commonly fried, mashed, or boiled, especially in Latin American cuisine.

Banana Varieties

• Gros Michel bananas are flavorful but vulnerable to Panama disease and leaf spot.
• Cavendish bananas are a hardier group.
• Cavendish bananas have been crossed with Gros Michel to produce commercial varieties.
• Other varieties include Cavendish, Valery, Lacatan, and Robusta.
• Valery, Lacatan, and Robusta are the top three cultivated varieties.

Planting Methods

• Bananas are propagated vegetatively.
• Pseudo stems produce maiden, water, and sword suckers.
• Water suckers have the same width from top to bottom.
• Water suckers originate from a remote or grandparent corm.
• Do not use water suckers for planting.
• Sword suckers are vigorous, produced by the main stem, large at the bottom, and taper upwards.
• Sword suckers have long, thin leaves.
• Sword suckers are the best for planting.
• Maiden suckers are between sword and water suckers with tapering stems and narrower leaves.
• Maiden suckers are good planting materials.
• The best plants come from old stems' corms with one or two buds.

Growing and Planting

• Bananas grow for several years in alluvial valleys and plains.
• Banana plants can remain productive for 10–20 years without replanting.
• The average productive growth period without replanting is approximately 5 years.
• This 5 year period is common for crops planted on clayey soils.
• New banana planting materials must be free of pests and diseases.
• Inspect old corms or suckers for plant borers and nematodes.
• Remove all roots and trash, and cut away any decaying stem portions.
• Dip the stem in Nemagon with a sticker like Triton.
• Plant suckers or corms ("heads") in holes about 45cm wide and 45cm deep.
• Space plants about 2.4m x 2.1m apart.
• Spacing depends on soil fertility, land slope, and variety.
• Bananas are now sold by weight instead of by stem or bunch.
• Farmers aim to produce a high yield per hectare.
• Reducing the spacing between plants allows more plants per hectare, increasing yield.

Fertilization and Pruning

• Bananas need fertilizer to maintain high production levels.
• Apply fertilizer at least twice per year.
• Adjust fertilizer type and rate according to soil testing.
• A mixed fertilizer is generally recommended.
• Bananas do not usually show major mineral deficiencies.
• The approach to pruning suckers has changed due to selling bananas by weight.
• In fertile soils, keep up to four or five suckers per parent plant.
• In less fertile soils, allow only two suckers at different developmental stages.
• Decide if and how much sucker removal is needed.
• Remove unwanted suckers from the parent plant using a sharp tool like a cutlass.
• Cut between the sucker and the parent plant.
• Remove suckers furthest from the parent or on a lower slope.
• They are less firmly established.
• Make a smooth, clean cut to prevent infection.

Harvesting and Post-Harvest

• Cut off the top of the pseudo stem and leave it as mulch at the base of the plant.
• Pseudo stems can also be fed to cattle or used as supplementary feed.
• Most losses occur during harvesting.
• Bunches are often rejected if fruits are immature or bruised.
• Wrap young fruits in polythene bags to prevent grazing.
• Transport bananas from the field to boxing plants.
• Cut bananas into hands, wash, and box for shipping.
• Dip banana hands in growth regulators like gibberellins to improve post-harvest storage.
• Keep bananas at 13°C to 15°C with 85% relative humidity to extend storage time.

Pests and Diseases

• Banana bunches are sometimes encased in plastic bags.
• These bags can be coated with pesticides.
• The Cavendish banana cultivar is at risk of becoming unviable in the next 10–20 years due to lack of genetic diversity.
• 'Gros Michel' followed this fate.
• Lack of genetic diversity in bananas makes them vulnerable to diseases.

Panama Disease

• Panama disease comes from a Fusarium soil fungus (Race 1).
• Panama disease enters through the roots.
• The fungus spreads through water to the trunk and leaves.
• Gels and gums are produced that cut off water and nutrient flow, wilting the plant and exposing it to sunlight.
• Before 1960, "Gros Michel" was the main banana, but highly susceptible to Panama disease.
• Cavendish replaced Gros Michel because, among resistant varieties, it has the best quality fruit.
• Cavendish requires more shipping care, and its quality is debatable compared to Gros Michel.

Tropical Race 4

• Tropical Race 4 (TR4) is a Panama disease strain discovered in 1993.
• TR4 has eliminated Cavendish bananas in several Southeast Asian countries.
• This has not yet reached the Americas.
• Soil fungi spreads via footwear, clothing, or tools.
• TR4 is likely to enter Latin America this way.
• Cavendish is susceptible to TR4.
• Cavendish is likely to disappear from commercial production due to TR4.
• The only known defense to TR4 is genetic resistance.

Black Sigatoka

• Black Sigatoka is a fungal leaf spot disease first observed in Fiji in 1963 or 1964.
• Also known as black leaf streak.
• The disease spread through tropics via infected banana leaves used as packing.
• Black Sigatoka affects all banana and plantain cultivars.
• Photosynthesis is impeded by blackening of leaves.
• Leaves eventually die.
• Fruit production decreases by 50% or more.
• Bananas ripen prematurely, making them unsuitable for export.
• The fungus is becoming resistant to treatment.
• Treatment is costly.
• Intense spraying is raises environmental concerns.
• Some resistant bananas have been developed, but lack commercial acceptance due to taste and texture.

Banana Bunchy Top Virus

• Banana Bunchy Top Virus (BBTV) spreads via aphids.
• BBTV stunts leaves, causing a "bunched" appearance.
• Infected plants usually do not produce fruit.
• Mild strains exist but are mistaken for malnourishment.
• There is no cure for BBTV.
• Effects can be minimized by planting tissue-cultured plants, controlling aphids, and destroying infected plants.

Banana Bacterial Wilt

• Banana Bacterial Wilt (BBW) is caused by Xanthomonas campestris pv. musacearum.
• BBW was originally found on Ensete ventricosum in Ethiopia in the 1960s.
• BBW appeared in Uganda in 2001.
• BBW affects all banana cultivars.
• BBW has been diagnosed in Central and East Africa, including Rwanda, the Democratic Republic of the Congo, Tanzania, Kenya, Burundi, and Uganda.