Tropical Hawaiian summers are perfect for the heavy production of banana fruit. In fact, this time of year folks have such an abundant supply of the fruit that it is hard for a family to eat them all. Even using them for banana smoothies, pancakes, bread, fried bananas, banana chips and dried bananas, just to mention a few uses! Bananas are rich in nutrients and especially good for supplying potassium. Home grown bananas are a great way to reduced your grocery bill.
However, when crops like bananas, coffee, cocoa, macadamia, avocado and others are grown on a larger scale than the small farm or home garden, it becomes more of a gamble.
Farming for a living is challenging. It is enough to drive you bananas, especially if you are a commercial banana grower in Hawaii.
Our islands are ideally suited for producing delicious banana crops, but diseases like Panama Wilt and Bunchy Top Virus some times make it a real gamble. Fortunately there are varieties that are resistant to Panama Wilt. Banana Bunchy Top Virus is kept under control so far. This means that all infected banana plants must be removed to avoid the spread of the disease, and that means the cooperation of everyone.
Without cooperation, the disease will spread. If you have stunted unproductive banana plants, it might be a good idea to give Kamran Fujimoto a call at Hawaii Department of Agriculture, 974-4145. He can assist you in identifying the disease affected plants and what to do about it. Other resources include the Big Island Banana Association and the University of Hawaii College of Tropical Agriculture and Human Resources.
There may be another way of beating the virus. The University of Hawaii College of Tropical Agriculture and Human Resources (CTAHR) has been attempting to engineer virus resistant plants. This approach could also be used to build in resistance to other banana diseases. Another approach is to seek biological controls of the aphid that spreads the disease from one plant to another. These are long-term solutions. In the meantime, it is imperative that back yard gardeners make every effort to remove infected banana plants if they have them.
Despite these pesky diseases, you may grow this amazing plant, but be sure you get healthy plants with which to start. Most nurseries selling banana plants make sure that their stock comes from disease free sources, but be sure to ask.
The four secrets to success with bananas begin with the soil first. Banana plants thrive best on good soils fairly rich in organic material, and in moist situations, provided the soil is well-drained. They will grow in nearly any soil except one composed almost wholly of sand or rock. Bananas are seriously damaged by salt water and by high chloride accumulation in soils due to intrusion of brackish water in coastal areas.
The second secret is wind protection. Strong trade winds, tropical storms and the occasional winter storms can do serious damage. The leaves are likely to be tattered, therefore, plants should not be put in an exposed location. Tattered leaves cannot function as well.
Third is that varieties are important. The dwarf variety, Cavendish or Chinese, is better adapted to small garden conditions as it has a short, stout stem from 4 to 7 feet tall, with broad leaves borne on short petioles. It is somewhat hardier and more wind resistant than taller varieties. The fruit is of medium size, thin skinned, and of good quality. Growing larger, to 20 feet, the “Brazilian” banana is hardy and prolific, but not of as good quality. “Williams Hybrid” is larger fruited than the other two and yet not as tall as the apple. It is superior for home gardens and is grown commercially. Other less known varieties with potential are “Cuban Red”, “Dwarf Jamaican”, and the “Thousand Finger” of Indonesia.
Fourth is fertilization. Banana plants are heavy feeders and respond well to fertilization. Most Hawaiian soils are deficient in the major elements, nitrogen, phosphorus and potassium, and may be deficient in the elements, magnesium, calcium, copper and zinc. Bananas require all of them. As a general rule, bananas will thrive on the fertilizer mixtures shown by experience to be necessary on other crops grown on each particular soil type. The amounts required will also vary with the various soil types. Since the Bananas are heavy and constant feeders, results usually will be better from frequent light applications than from infrequent heavy applications. Mulches, compost and manures greatly benefit the plants as well.
While the plants are young, it is best to remove all suckers but one. This will force strength into the flowering stalk and leave one to take its place after fruiting. This way, larger bunches of fruit can be expected. Later, when the mat has matured, from three to five stalks may be allowed to grow if well spaced. Bananas harvested seven to 14 days before ripening and hung in a shady, cool place on the bunch will develop their flavor and nutritive value better than if allowed to ripen on the plant.
Bananas are hardy as far as pests are concerned. Occasional sprays of fungicides may be needed to keep leaves and fruit free of streaking or spotting fungus organisms. Be sure to read and follow manufacturers directions on the label.
The main disease problem to avoid besides Bunchy Top is Panama Wilt. Bluefield bananas are susceptible as are several Hawaiian varieties. If the disease is present, plant resistant varieties like Williams and Cavendish, since there is no economic cure for the disease.
As an additional point of interest, there are two species of ornamental bananas that are quite cold hardy and can be grown at high elevations in Hawaii even where heavy frost occurs. In fact, they have been grown as far north as Western British Columbia and on the east coast to Washington DC. The two species are Musa bajoo from Japan and Musa sikkimensis from the high Himalayas. In humid climates with hot summers and sub freezing winters, they die back to the ground. Given a protective layer of mulch, they emerge in the spring to give a lush tropical look to the temperate garden. For example, there is a beautiful stand at the Fiji House near the University of Washington campus in Seattle.
This weekly column is provided by the University of Hawaii at Manoa College of Tropical Agriculture and Human Resources Cooperative Extension Service.