Considerations when Pruning

Other Considerations when Pruning
1. Select only the parts to be pruned (minimal pruning)
2. Cut small branches first followed by large branches (minimal pruning only)
3. Always make a clean cut at the base of the branch and avoid leaving stumps where unwanted water sprouts may grow
4. Paint or spray the open cut with fungicide, tar or disinfectant when pruning is done during wet season
5. Remove all debris and maintain cleanliness of the surrounding areas.
Nutrient Management
In the first five years, the trees need high rate of nitrogen fertilizers. To promote faster vegetative growth, organic fertilizer application is also recommended. As the trees reach bearing age, more emphasis should be given on phosphorous and potassium. Phosphorous fertilizer promotes root and flower development while potassium is for fruiting and ripening. Apply fertilizercontaining 4-5% phosphoric acid and 8-15% potash.
Important Considerations in Fertilizer Application:
1. When applying fertilizer, dig a few holes (6-8 holes) around the tree or a canal within the area covered by the canopy. For big trees, follow canopy drip line.
2. The zone of maximum and efficient utilization of fertilizers is 30 deep and 100 cm from the trunk of 5-10 year old trees. This goes a little farther as the tree crown becomes wider
3. The preferred time of fertilizer application for non-bearing trees or at the juvenile stage is at the start and before the end of the rainy season, when the soil is still wet. Fertilizer can also be applied during the dry season if there is irrigation.
4. The procedure for fertilizer application is similar for both bearing and young trees.
5. At flowering, spraying of foliar fertilizer is recommended as supplement.
Flower Induction
In inducing mango trees to bear flower, the following should be considered:
1. Different mango varieties have varied flowering and fruiting habits. The ‘Carabao’ variety under normal conditions bears fruits every two to three years.
2. Chemical flower inducers should not be used under the following circumstances:
* When the tree is too small or still young
* When the leaves and buds are young
* When the tree is weak and sickly
* During rainy days
* Just after harvest or when the tree has fruits or is in flushing stage
3. High dosage of flower inducers (2.0 to 3.0% KNO3 ) should be used when:
* Trees are just starting to mature
* Leaves and buds are maturing
* The tree is healthy with vigorous buds and leaves
* During cloudy weather
* Sprayed six to seven months after harvest
4. Use low dosage of flower inducers (1.0 to 2.0% KNO3 ) when:
* Trees are big, old or fully mature
* Leaves and buds are fully mature
* Tree is healthy with dormant buds
* Sprayed during sunny weather
* Sprayed seven to nine months after harvest
5. Induce flowering only once a year
6. From flowering to harvest, it takes 7-8 months to rejuvenate and accumulate enough nutrients for the next fruiting season
7. Trees that bear fruits last season but have not flushed should not be induced to flower
8. Spraying should be done when the tree and leaves are dry and with no expected rain within the next 6 hours
Potassium nitrate is the generic name of chemical flower inducer in mango. The chemical symbol of this compound is KNO3. This contains 13% nitrogen and 46% potash, thus, 13-0-46. When sprayed, it supplies the potassium deficiency of the tree and in the process, induces flowering.
When spraying potassium nitrate, follow this simple steps:
1. Prepare a 1-3% solution depending on the condition of the tree.
2. Spray the leaves and branches totally wetting but not dripping.
3. Spray early in the morning (from sunrise to 9:00 am) or late in the afternoon (from 4:00 pm to 5:00 pm). This prevents leaf burning due to sunlight.
Water Management
For young mango trees, weekly manual watering should be done during dry months by saturating the soil with enough water followed by mulching. If drip irrigation is available, fertilizer application can be incorporated in the irrigation water.
For flowering trees, apply water weekly during flower initiation and fruit development and stop one month before harvest. Irrigate developing flowers and fruits to enhance fast development, minimize fruit drop and increase fruit size. The volume of water ranges from 60 to 100 liters per tree depending on size.
Pest Management
Fruit Protection
Wrapping or bagging of fruits is practiced in many areas because of the following:
* Minimizes incidence of fruit fly and other fruit insects
* Minimizes disease (fungal) infection
* Reduces incidence of mechanical damage
* Paper used serves as absorbent for latex flow during harvest
* Results to cleaner fruit skin and more attractive light green color
* Provides an estimate of harvestable fruits per tree
In general, bagging is recommended to protect fruits from pests and to reduce spraying of insecticides. This practice is done when fruits are about chicken’s egg size (55 to 60 days after flower induction)
Insect Pests
1. Mango leaf hopper
Damage: Sucking of plant sap causes withering and drying of tender shoots, flowers and very young fruits. In the process, insect secretes sticky fluids (honeydew) that promotes development of sooty mold, fungal disease.
Control: Spray recommended chemicals starting from flower/bud formation to fruit setting. Confidor is effective against hoppers.
2. Mango tip borer
Damage: Shoots wilt and terminal parts die. If infested, panicles break and the flowers shed off.
Control:
* Prune dead branches to discourage spread of insect. Burn parts that are affected.
* Since the adults start to destroy the flowers from the bud emergence to elongation, it is necessary to spray insecticides to protect these stages especially during hit months. Insecticides used for mango hopper control are also recommended for tip borer.
3. Twig cutters
Damage: This is very destructive during the dry season. When present, the number of flowers that will be formed is reduced. The most visible indication of the problem is the presence of dead twigs and leaves in the canopy.
Control:Pruning and burning e dead branches to discourage spread of insect. Protect flushes from adults by spray application of insecticide.
4. Pulp weevil
Damage: This is a unique pest since the larvae of the insect feed inside the fruit and destroy the pulp, yet the peel has no visible damage even up to harvest. The insect is present only in some parts of Palawan.
Control:
1. Pruning of crowded mango trees allowing light to penetrate in the canopy is unfavorable to the weevil. Dead or overcrowding branches should be removed.
2. Keep each tree free from weeds, fallen leaves, fruit droppings and other debris. Cultivation of soil is advantageous since this exposes and kills the weevil hidden in the soil after harvest. Burn infested fruits to eliminate sources of infestation during the next fruiting season.
3. For chemical control, Cypermethrin at 50 ml/100 li water provides good protection against the weevil. Fenvalerate and Carbaryl are also effective against the pest. The insecticide should be applied at 14 days interval from fruit set to full development of the fruits.
Note: Insecticides are not effective once the pest is inside the fruit.
5. Mango fruit fly
Damage: Adults lay eggs on mature fruits and larvae feed on the flesh. Affected fruits drop to the grown and are easily contaminated by microorganisms.
Control: Bagging, collection and proper disposal of fallen fruits and harvest at the proper stage of maturity. If chemicals have to be used, spray at 90 or 110 days after induction.
6. Mealy bugs
Damage: Attack newly-flushed leaves, flowers and fruits and suck vital plant saps. Affected parts turn yellow, dry up and eventually fall.
Control:Removal of infested fruits, flowers and leaves. Spray insecticides to kill ants associated with mealy bug.
7. Capsid bug
Damage: Attacks young leaves, twigs and fruits. Saliva of the insect is very toxic and the site of the puncture is marked by sunken blister. The lesions turn brown after 24 hoursbecoming black and scabby in 2-3 days. Infected young fruits fall prematurely. Locally, the damage is called ‘kurikong’ or ‘armalite’ or ‘buti’.
Control:Prune trees before induction, underbrushing areas around the tree, spray insecticide late in the afternoon and remove alternate hosts like cashew, guava and cacao.
8. Mango cecid fly
Damage:Adults, which are mosquito-like in appearance, lay eggs on new flushes. The larvae mine the leaves producing galls or swelling of tissues. Heavy infestation results to wrinkling of the leaves; the leaves remain yellow in color. Close examination of the leaves shows dark green, circular galls randomly distributed on the leaf blade.
Control:
1. Prune or cut infested leaves and burn.
2. Practice orchard sanitation. Underbrush weedy areas since adults stay in these areas.
3. Spray either Sevin, Decis, Karate or Stingray (3-4 tbsp per 16 liters water) to minimize damage.
9. Scale insect
Damage: In nurseries, leaves of grafted mangoes are readily infested with scale insects, causing them to dry and fall. On bearing trees, high populations of the insect cause blackening of canopy due to the growth of the fungus ‘sooty mold’. Affected leaves become covered with thin, black papery film which produces unsightly appearance. In addition, affected branches are deformed producing gall like protruberances.
Control:
1. Young scale insects are carried and distributed by red ants to different parts of the tree. To prevent infestation, destroy ants by spraying Malathion at 1 ½ tbsp per 16 liters water, Decis at 1-5 tbsp per 16 liters water or Karate at ¾ – 1 ½ tbsp per 16 liters water.
2. Prune and burn heavily infested plant parts like branches and leaves. This should be followed by spray application of insecticides recommended for this pest and application of high dose of nitrogen.
Important Diseases
1. Anthracnose
Damage: This is the most prevalent and destructive disease of mango both in the field and after harvest. Symptoms are exhibited not only on the fruits bust also on flowers and leaves.
Prevention and Control:
1. Field sanitation
2. Prune infected branches, burn them and bury the trash
3. Schedule flower induction after the rainy season or during the dry months
4. Include insecticide and fungicide when spraying flower inducer
5. Wrap the fruits 50-60 days after flowering to protect them from pests and diseases.
6. After harvest, practice hot water treatment
2. Stem end rot
Damage:This is another post-harvest disease of mango and appears during storage and transit. The disease occurs only in ripened fruits.
Control Measures:
1. During harvest, leave one centimeter pedicel attached to the fruit to avoid too much latex staining. The casual organism germinates and grows in the presence of latex.
2. Pack mangoes in boxes of two layers to avoid injury due to compaction
3. Do not use organic materials during packing
3. Scab
Damage: The disease occurs in nurseries and during moist weather. Damage occurs while fruit is still green
Control Measures:The methods of control are similar to that of anthracnose. However, scab is effectively controlled using copper fungicide.
4. Gummosis
Damage: This fungal disease causes stem bleeding, crown and root rot. Infection may start during the seedling stage and may appear during both dry and wet season.
Control Measures:
1. Plant in well-drained soil.
2. Disinfect nursery sites before planting with methyl bromide, Chloropictin or other fungicides
3. Avoid too close planting to allow aeration and ventilation.
4. Remove dirt, weeds or trash
5. Avoid dumpy soils for long duration at the base of the trees.
6. Cultivation to aerate the soil is necessary to reduce fungal infection
7. Prune crowded branches
8. Foliar spray of ethyl phosphate metaxyl ot prosethal at 2g per liter water every 80 days
9. Drench infected parts, exposed damage and cover with slurry of fungicide
5. Sooty mold
Damage:The causal organism (fungus) develops in the presence of honeydew excreted by insects like hoppers, scales and mealy bugs. As such, it stains the fruits and makes them look dirty and unattractive.
Control Measures:Spray insecticide to kill hopper, scales and mealy bugs. Bag fruits at 60 DAFI.
Integrated Pest Management
This involves the following practices:
1. Planting of healthy seedlings.
2. Proper land preparation and cultivation. This includes clearing and removal of infected plant residues in the field and exposing the soil to direct sunlight. This will help eliminate soil-borne pathogens.
3. Proper irrigation and drainage to avoid water logging and reduce water-borne diseases.
4. Correct distance of planting and row orientation. This will allow maximum sunlight penetration, aeration and ease of farm operations such as pest and disease control, cultivation, plowing, smudging, fertilizer application, harvesting, etc.
5. Introduction and maintenance of natural enemies and other biological control methods like entomophagous fungi against mango hoppers. Intercropping with trees that can repel harmful insects and serve as wind breaks.
6. Application of recommended fertilizers and soil conditioners, maintain the right pH of 6-7.
7. Practice of clean and sanitary culture. This includes pruning, weeding, thinning, cultivation and burning of infested debris.
8. Using insecticides and fungicides derived from plant extracts like neem, china berry and custard apple.
9. Use of baits and light traps for fruit pest (fruit fly and borers).
10. Monitoring of pest population and application of pesticide only when necessary.
11. Combine cultural, biological and chemical means to minimize pests.
Harvest Management
The following are the indications that mango fruits are ready for harvesting:
1. At 110 days (for very warm and dry environment), 120 days (warm climate) and 130 days (cool and high elevation) after flower initiation;
2. When the flesh is turning yellow;
3. When powdery deposit or “bloom” on the surface of the skin is detected;
4. When fruit has flattened shoulders at the stem end; or
5. When the pedicels of fruits turn dark green to brown in color;
6. 75% mature fruit samples sink when submerged in 1% salt solution
Harvesting by hand is the most effective way in order to avoid bruises or damage of the fruits. The best time to harvest is between 9:00 am and 3:00 pm since the tree and fruits are dry and the latex flow is minimal. Harvest with pedicel intact (1.5-2.0cm).
Trim off pedicels and let the latex dry before packing.
Post-Harvest Treatments
In order to sell quality fruits, the following post-harvest treatment are practiced:
1. Washing of fruits in water
– To remove dirt on the surface.
2. Hot water treatment
– This involves heating dipping the fruits for 5 to 10 minutes in heated water (52-55°C). This is followed by hydro-cooling (washing in cool water) and air drying.
3. Vapor Heat Treatment (VHT)
– This involves heating the fruit with water vapor saturated air until the fruit pulp reaches 46°C for 10 minutes.
Ripening of Fruits
Fully mature fruits may be induced to ripen faster and with uniform color. There are two ways to do this:
1. Use of calcium carbide (‘kalburo’) at the rate of 5 to 6 grams per kilo of fruit. This is done by wrapping the calcium carbide in paper or leaves and placed at the bottom of the container. The container should be covered for 2 to 3 days. For best result, allow fruits to produce yellow color and place ‘kalburo’.
2. Use of ethylene gas or ethyl water solution. The use of ethylene gas involves a chamber while in ethyl solution, the fruits are simply dipped in the solution.
Mango Processing Technologies
Being a perishable commodity, mango is processed in various forms to:
* Protect it from chemical deterioration and microbial contamination
* Provide additional income
* Ensure adequate and continuous supply of mango products the whole year round
Processed forms of mango:
* Dried mango
* Mango chutney
* Mango jam
* Mango cubes
* Burong mangga
* Mango atsara
* Mango puree
* Mango pickles (sweet and sour blend)
* Mango candy