The mango, Mangifera indica, is a common landscape tree in many Hawaiian gardens and roadsides. As the scientific name implies, it has ties to India, having its roots in the northeast region of India to present day Myanmar (formerly Burma),
The mango, Mangifera indica, is a common landscape tree in many Hawaiian gardens and roadsides. As the scientific name implies, it has ties to India, having its roots in the northeast region of India to present day Myanmar (formerly Burma), where it has been cultivated for more than 4,000 years.
Today, it is found growing in all tropical areas of the world and has become ingrained into many local cultures.
The first mango plants arrived in Hawaii by about 1824 from Manila and were planted in downtown Honolulu by Don Marin, an early Hawaiian horticulturist (more on Marin next week). A few plants also were taken to Wailuku, Maui.
While these original plants served as the parental plants for many subsequent trees, many more varieties and cultivars were introduced to Hawaii from around the world.
Nearly everyone has a favorite mango, from common, Chinese, Perie, Haden, etc. And mangoes are not only for eating fresh, but used in a number of creative ways from pickles, relish, chutney, baked goods, and sauces.
What all mangoes have in common is the consideration a gardener needs to make prior to planting.
When deciding to plant a mango tree, proper location, cultivar characteristics and spacing are very important to consider. Mangoes do best in a lowland tropical climate (up to about 2,000 feet) with rainfall ranging from 10 to 100 inches annually. Soil pH should be slightly acidic, well-draining and not too fertile, which leads to excessive vegetative growth and little flower development.
Many cultivars of mangoes are available here in Hawaii and selection should be of a named variety that does well in your particular area and you find desirable in taste and appearance.
Mango trees can easily grow to more than 50 feet tall, dwarfing everything around them, so spacing to other plants, buildings or utility lines is critical unless pruning for size control will be practiced.
Also, harvesting fruit from a tree more than 20 feet tall is difficult to manage and anything taller multiplies the difficulty of harvesting quality fruit.
Care and maintenance of mango trees should follow this general protocol.
Complete fertilizers (8-2-9 or similar) should be applied on a regular basis, usually half before flowering and the other half after harvest within the canopy dripline. Application rate is 1 pound of fertilizer for every inch of trunk diameter at 4 feet height per year. Pruning should be done shortly after final harvest.
Flowering in mangoes can be stimulated by applications of 1 to 8 percent of potassium nitrate solution to dormant buds during months with cooler night temperatures. Only those plants with mature leaves will respond.
Response to night temperature and potassium nitrate concentration is cultivar specific and polyembronic cultivars (seeds made up of more than one embryo) are more sensitive than monoembroyic cultivars. Bud initiation was found to occur within two weeks on some branches, with remaining branches requiring additional sprays of potassium nitrate.
When application is made during periods with night temperatures above the threshold temperatures, stimulation of vegetative growth is more likely to occur.
Whether you live on the windward or leeward side of the island, fungal diseases can be devastating to mango production because of infection of flowers.
For those on the windward side of the island, rainy weather normally contributes to creating favorable conditions for the growth and spread of anthracnose, a fungal disease caused by Colletotrichum gloeosporides.
Anthracnose of mango is observed as the black lesions covering the flower panicle (buds, flowers and floral branching stem). From a distance the entire spike appears to be blackened, and it is one of the major reason why we have limited production in Hilo despite having an abundance of flowering.
Fruits that do set are infected with the fungus where it can cause tear stains (rows of small black spots that appear to run down the skin of the fruit) or the large black lesions on ripening fruit. The fungal organism will infect the very young fruit within the flower or shortly thereafter and wait until the fruit starts to ripen and soften before growing.
Therefore, covering or bagging the fruit prior to harvest will not prevent the black lesions from forming on ripening fruit.
On the leeward side, the fungal disease powdery mildew caused by Oidium mangiferae is a major cause of no fruit set.
Powdery mildew is favored by warm, dry weather prevalent on the leeward side. Symptoms of powdery mildew are a white powdery coating on the flower panicle leading to browning of tissues and death of the flowers. Plants are most susceptible at full bloom.
Even if fruit set occurs because of mild infection, fruits can develop purple-brown lesions that crack and form corky tissue. Young developing leaves also might be infected, causing leaf curl and necrotic spots.
If either fungal disease is known to be present in your area, the best control strategy would be to create environmental conditions that are less conducive to the development of the diseases. This might include rain shelters for anthracnose. Consideration should be given to chemical control of these diseases, which includes the use of either conventional or organic fungicides.
Read labels for approved use on mangos and directions for application.
A common question many people have is when to harvest mangos.
Those that change color to yellow or orange or red are fairly easy to estimate degree of ripeness.
Another general method to gauge to degree of ripeness is to observe the fruit shoulders. When the fruit shoulders have risen above the stem-end and there is a slight skin color break on the fruit, it can be picked.
For more information about mangos and other gardening topics, visit the CTAHR electronic publication website at www.ctahr.hawaii.edu/Site/Info.aspx (keyword: mango) or visit any of the local Cooperative Extension Service offices around the island. I can be reached at russelln@hawaii.edu.
