Mangoes can be propagated sexually through seeds and asexually (vegetative) through grafting, budding or inarching.
1. Sexual Plant Propagation
Advantages
· Trees planted from seeds are deep-rooted, thus, anchorage and nutrient exploration is enhanced.
· Long lived. Trees planted from seeds survived over a hundred years and are prolific producers of fruit.
· It is an easy and fast way of multiplying a variety.
Disadvantages
· Seeded trees do not produce fruits that are “true to type”, which means that trees coming from superior trees do not always come up to the expectations of the growers such as size and sweetness of fruits.
· Trees have enormous size(tall with large canopies), as such many of the cultural practices like pruning, spraying, bagging and harvesting are difficult to implement.
· Seeded trees take longer time to bear fruits. Many produce fruits only after 8 to ten years from planting.
2. Asexual Plant Propagation
Advantages
· Produce fruits that are “true to type”. When planted, the expected characters of the parents are carried to the next generation.
· Earliness to bearing (precocity) takes shorter time. Under proper management, grafted trees bear fruits one to two years after planting. However, it is recommended that four years of growth should be maintained for proper establishment of trees in the field.
· Trees are generally small in size and several numbers can be planted to a hectare. In addition, many of the recommended cultural practices can be implemented without much difficulty (spraying, cultivation, bagging and harvesting)
Disadvantages
· Grafted trees are shallow-rooted and are easily uprooted by strong winds and typhoons.
· It is a common notion that grafted trees have shorter life span. However, this is yet to be proven since many grafted trees are more than 80 years and are still vigorous and productive.
3. Growing of rootstocks
Seed collection
· Collect seeds from fruit retailers, processors and institutional sources.
· Seeds may come in single variety or in a mixture of different varieties. For rootstocks, use ‘Carabao’, ‘Pico’, ‘Indian’ or ‘Pahutan’.
· Avoid mango seeds which were extracted mechanically. These seeds can have broken cotyledons or injured embryos resulting in poor germination.
· Seeds kept in frozen storage have reduced viability.
· Seeds should come from mature fruits only. They are available from January to June with peak in April and May.
Transport of seed
· For short distances, dump seeds in trunk haulers or trailers. Do not place in close containers, however if needed, kaings are suitable.
· For long distances, dehusk the seeds and cover them with moist sawdust. This keeps seed viable for up to a week.
Dehusking
The husk of the seed prevents the entry of water and oxygen needed on germination. Dehusk seeds to prevent rotting and failure to germinate. To dehusk:
· Cut from the base of the seed,
· Split it off, and scoop out the seed (embryo). Dispose the husk and sow the seed immediately.
Sowing
Nursery rows are established in small areas of land within the nursery in which seedlings are grown at closer spacing until they are asexually propagated.
For seedbeds with light to medium soil, sow seeds with the concave side down at 1.0 to 2.0 cm deep or at the subsurface of the medium. Otherwise, seedlings will develop crooked shoots and roots that snap off when uprooted by hand.
· Seedbeds’ sizes may vary but usually measures 1.0 meter wide and 2.0 to 3.0 meters long.
· Raise the seedbed 10 to 15 cm high and its side may or may not be bordered by hollow blocks or bamboo walls.
· Fill up the seedbed with fine sand, coir dust, loam soil, or any of these combinations provided it is well drained. Sand facilitates uprooting, with minimal damage to roots.
· Keep under shade. If it is in the open field, use a mat of woven pieces of bamboo or any suitable material over the seedbed to provide shade (net).
· Seeds germinate 10 to 15 days after sowing. Seedlings are ready for transplanting when these have two to three pairs of green leaves (25 to 30 days after sowing). Put seedlings in plastic bags (7 inches x 10 inches) containing two parts garden and one part manure.
In the absence of seedbed, spread on the ground by covering them with coir dust, sawdust, or rice hull to pre-germinate.
Transplanting and Potting
· Transplant seedlings at 30 cm x 60 cm in nursery rows or individual containers four to six weeks after germination
· Site should be well-drained and fertile
· In the absence or lack of suitable area for nursery rows, seedlings are transplanted directly in plastic bags measuring 13 to 15 cm in diameter and 20 to 25 cm deep.
· Plastic is highly suitable because they are cheap and less bulky compared to tin cans or clay pots.
· Prior to transplanting, each bag is perforated at the sides to provide drainage and its two bottom corners are pushed inward to make its bottom flat when filled with growing medium. This provides stability for the plant
· Use an equal proportion of the fine sand, garden soil and compost as growing medium. Fill the bag until about two cm from the rim.
Care after Potting
· Place the seedling under the shade of trees or coconut and banana leaves. Net screen may also be used.
· Water seedlings regularly, especially during the dry months. Mortality of seed is high when water becomes a problem. It is recommended that water should be applied directly in the bag and not poured on the leaves to minimize the incidence of diseases, especially anthracnose.
· Inspect seedlings weekly for presence of insects, particularly scales, corn silk beetle, tip borer, cecid fly and diseases such as anthracnose and seedling rot. If these problems occur, apply insecticides or fungicides.
· Fertilize with 3.0 to 5.0 grams of ammonium sulfate per plant, a month after planting and two to three in a year.
· Seedlings can be grafted when their stems attain ‘pencil’ size diameter and are approximately 8 to 10 months old.
4. Selection of Scion
· Collect scions from bearing trees of outstanding cultivars with the following characteristics:
o Mature
o 6 to 8 in inches long, 1 cm in diameter
o About six to 10 months
o Plump terminals
o Have active growing points
· Collect scions from the current season’s flush
· Use younger scions
· Defoliate scions after collections
· When transporting to a distant place, wrap the scions with moist newspaper, paper towels or sphagnum moss before placing them in polyethylene plastic bags or Styrofoam box until they reach the nursery
5. Cleft Grafting
This is the most popular and successful method of asexual propagation in mango. It is easy to perform and the percentage of success is high
Steps in cleft grafting
1. Collect scions from scion grove using a pruning shear/knife. Obtain scions with pencil size diameter and protruding buds
2. Prepare the scions by cutting them to about six to eight inches. Remove the remaining leaves.
3. With a sharp grafting knife, cut the rootstocks 15 to 16 inches from the base. This will give allowance for the second grafting if the earlier procedure fails.
4. Make incision on the cut portion just enough for the pointed end of the scion to be inserted
5. Make a perpendicular cut on both sides of the scion to form a ‘wedge’ shape tip.
6. Insert the ‘wedge’ shape portion of the scion in the rootstock, aligning their cambium layers properly.
7. Securely tie the point of union using a plastic strip to ensure good trip
8. It is also recommended to cover/wrap the remaining portions of the scion with plastic strip to minimize drying
9. Observe the growing points after 10 to 15 days and open the wrapped portion to allow shoot development
10. Remove water sprouts to ensure good growth
11. Place the grafts under shade. Shoots will develop from the scion after two weeks if grafting is done properly. When this happens, loosen the plastic that covers the tip to enhance development.
12. Do not remove the remaining plastic that ties the scion until the wound is totally healed
1. Dig seedlings carefully and see to it that their roots remain covered with the soil.
· The size of the ball increases with plant size
· For a one-year old grafted mango, a ball measuring about 15 to 20 cm in diameter planted into a 25 to 30 cm deep hole is sufficient
2. Dig carefully when the soil is moist to avoid breaking it and in turn disturb the root system
3. When balling is completed, lift the plant from the hole
4. Wrap the ball with old sacks
5. Place the newly balled plant under the shade and plant them as soon as they recover from balling stress.
6. Side Grafting
Mature seedlings with oversized stems can be propagated through side grafting. With this method, the scion is placed in a portion of the rootstock where there is maximum contact between the cambium layers of the two parts.
High percentage of successful side grafting can also be achieved. The procedures are the same in cleft grafting except that the vertical cut is made at the side of the rootstock. Exposed parts should be painted with used oil.
7. Splice grafting
Splice grafting is another method of asexual propagation in mango. However, it is seldom used due to the difficulty of fitting the scion with the stock.
Theoretically, it is better than cleft grafting because healing would be faster since there is only a small wound to heal. Moreover, the diagonal cuts on the rootstock and scion give greater contact between the cambiums of the scion and the stock.
8. Care of the Graft
Water the grafted plants regularly. If grafting is successful, new shoots will develop in two to three weeks. Remove the plastic cover of the scion so it will not interfere with the growth of the shoot. However, retain the plastic that secures the scion with the stock until the shoot has matured. Apply fertilizer and control pests and diseases regularly.
9. Balling
The practice of lifting the seedlings grown in nursery rows by digging their roots is called balling. This is usually done for overgrown plants.
Note: Balling is seldom done for mangoes, since grafts are grown in containers (cans, plastic bags, etc.)
10. Hardening
Grafted mangoes are ready for field planting 5 to 6 months after grafting, provided proper care is given. However, it is suggested that young grafts should be hardened prior to planting. This is done by gradually exposing the grafts to light and with holding water. By doing so, you prepare the plant to the harsh environment in the field.
