Production of Pummelo, Part 1 Primer and Cultivars

Pummelo (Citrus maxima), Suha or Lukban is one of the most popular specie of the Citrus family. It has a long shelf life that it can be transported to distant markets.

The pummelo tree grows from 5-15 meters in height and has low spreading branches with a canopy size ranging from 500-900 centimeters. Its leaves are ovate to oblong with leaf size ranging from 5 cm x 12 cm to 8 cm x 20 cm wide when fully expanded.

The flowers are located either in the axial or terminal point, raceme type of inflorescence and fruit is yellowish green in color, nearly round to pear-shaped. It matures five to six months after flowering. The juice vesicles are either white, light pink or red, depending on the variety. Seeds are few to nil ridged, deltoid to globous in shape and mono embryonic.

Uses

  • The fresh juicy pulp vesicles are eaten fresh out of the hand or in the fruit salad and sometimes the juice is extracted for beverage.
  • The white inner part of the peel can be candied after the outer peel containing oil glands have been removed.
  • In Vietnam, the aromatic flowers are used in making perfumes.
  • The wood is used for tool handles and firewood while leaves, flowers, fruits and seeds are sometime used as herbal medicine to treat cough, fevers and gastric disorders.

Properties

The edible segments form only a small fraction of the thick-skinned fruit. A 100g edible portion is composed of the following:

  • Water (g) 89.00
  • Protein (g) 0.50
  • Fat (g) 0.40
  • Carbohydrates (g) 9.30
  • Vitamin A (IU) 49.00
  • Vitamin B1 (mg) 0.07
  • Vitamin B2 (mg) 0.02
  • Niacin (mg) 0.40
  • Vitamin C (mg) 44.00

Recommended Pummelo Cultivars

a. Magallanes

  • Origin Davao City
  • Yield (No of fruits /tree 227.00
  • Weight of fruit (g) 859.03
  • Edible portion (%) 44.20
  • Total soluble solids (%) 9.00
  • Flesh color Pink

b. Amoy

  • Origin Canton, China
  • Mantan Yield (No of fruits /tree 203.00
  • Weight of fruit (g) 814.83
  • Edible portion (%) 52.85
  • Total soluble solids (%) 9.22
  • Flesh color Pink

c. Siamese

  • Origin Thailand
  • Yield (No of fruits /tree 252.00
  • Weight of fruit (g) 1050.91
  • Edible portion (%) 51.07
  • Total soluble solids (%) 9.41
  • Flesh color White

d. Dela Cruz Pinl

  • Origin Lubongan, Toril, Davao City
  • Yield (No of fruits /tree 347.00
  • Weight of fruit (g) 784.76
  • Edible portion (%) 57.57
  • Total soluble solids (%) 9.67
  • Flesh color Pink

Soil and Climatic Requirements

1. Soil Requirement

  • Adapted to a wide range of soil types provided, they are reasonably deep, well-drained and aerated with high moisture retention.
  • Optimum pH range from 5.5-6.5.
  • Liming to increase pH when it is below 5 (acidic).
  • Water logged soils, sticky heavy soils, wet soils and those underlain with hardpan should not be used.

2. Climatic Requirement

  • Grows in lowland tropics in elevation up to 400 meters above sea level with optimum temperatures of 23-300C.
  • Optimum light requirement of 32.3-86.1 klux
  • Annual rainfall requirement of 1500-1800 millimeters.

Production of Seedlings for Rootstocks:

  • Select fully developed seeds from mature/ripe fruits of Calamandarin (bleieved to be a hybrid of calamondin and mandarin)
  • Seeds should be selected from fruit trees that are free from Citrus Canker (Xanthomanas Citri) to avoid contamination on the seed.
  • Fruit that dropped or fall on the ground should not be picked up and use as seedlings for rootstock.
  • Disinfect the seeds with CHLOROX at 5% solution, rinsed with tap water and air dry before sowing.
  • Seed beds (nursery) should be isolated from existing citrus orchard to prevent possible contamination through insect vectors.
  • Soil media should be light type (sandy loam) and free from any soil borne insect pests like root grubs and nematodes.
  • Sterilize the soil media.
  • Extracted seeds should be sown immediately to avoid drying.

Care of Seedlings for Rootstock

  • Water the seedbed to facilitate germination.
  • When seeds started to germinate, exposed the seedbed to sunlight. Do not put shades. Shades provide a microclimate which favors the growth of dumping-off pathogen. Seedlings that grow without shades are hardy and free from dumping-off disease.
  • Seedlings do not need too much water. Too much water on poor drained beds predisposes the seedlings to dumping-off disease.
  • Spray chemicals to protect young seedlings from pests and diseases.
  • Recommended minimum dosage should be used to prevent leaf burn.

Potting and Transplanting of Seedlings

  • Seedlings are ready for potting 21-28 days after germination in “7 x 12” x .003 polyethylene plastic bags containing garden soil and place them in the nursery.
  • Avoid transplanting seedlings with deformed root system (goose-neck root)
  • Calamandarin seeds are polyembryonic thus from 1 seed, 2-3 seedlings germinate. One of the seedlings that germinate is an off-type. This seedlings are characterized by their stunted growth, weak and the leaves produced are smaller that other seedlings. These seedlings should be eliminated.
  • Water immediately the newly potted plants.
  • Fertilize the seedlings when signs of new shoots or growth have developed.

Asexual Propagation and Care of Budded Seedlings

  • Rootstocks are ready for budding in 6-8 months; or at least pencil-sized in stem diameter.
  • Apply nitrogenous fertilizer at 5-10 grams per plant 2-3 weeks before budding.
  • A round bud-stick give more good buds that angular bud-stick.
  • Budding should be done at a height of 6-8 inches above the ground level.
  • Do not fertilize newly budded plants; unless the bud eye have shown signs of growth.
  • Remove the wrap of bud 3 weeks after budding.
  • To hasten growth of bud-eyes, “lopping” or “cripping” the top of the seedlings 2-3 inches above the bud is recommended.
  • When bud-eyes started to germinate; decapitate the rootstock 1-3 inches above the bud-eye union to force the growth of the bud-eye or scion.
  • Weeding should not be done when the scion are succulent and tender, thus are susceptible to breakage when touch.
  • Budded plants are ready for planting at 8 months old.

For more info, contact:

Dept.of Agriculture
D.A. Compound, Elliptical Rd., Diliman,Quezon City
Tel. Nos. (632) 929-6065 to 67 / 920-3991 / 928-1134
Web: www.da.gov.ph

source: www.usm.edu.ph

 

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