- Clear/remove all stumps and grasses
- Plow twice and harrow thrice to loosen the soil.
- If the soil is acidic, incorporate dolomite lime during plowing and harrowing
- Get soil sample for analysis.
Field Layout and Distance of Planting
- The field layout should be either square or quincunx method depending on the topography of the orchard.
Distance of Planting
- 10 m x 10 m = 100 seedlings/hectare
- 8 m x 10 m = 125 seedlings/hectare
- 6 m x 8 m = 208 seedlings/hectare
- 8 m x 8 m = 156 seedlings/hectare
Preparation of Holes and Planting
- Dig a cubical hole measuring 50 cm. Wide and 50 cm deep. The hole will be filled up with a mixture of 50% decomposed measure, 50% top soil and 2 tablespoon of nematicide.
- Remove the plastic bag and plant the seedling into the prepared hole without breaking the ball of soil. Prune the roots to enhance root branching.
- Plant young plants at their dormant stage.
- Cover the hole with the soil-manure and press gently.
- Plant during the rainy season.
Care of the newly planted seedlings
- Water the plants immediately after planting to assure close contact between soil and roots and prevent wilting.
- Apply fertilizer when the newly planted trees started to developed new growth.
- Weed control – weeds compete with the seedlings for nutrients, sunlight and water.
- Mulching the trees with grasses, rice straw, rice hull and banana pseudostem will conserve soil moisture during dry period, prevent the growth of weeds and as source of organic matter after decomposition.
- Wounds on the bark and branches should always be painted with water repellant paints.
- Plowing and planting of intercrops should be 1-2 meters away from the rows or hills of the trees to avoid injury on the trunk, branches and roots
- Prune the young pummelo tree and leave three main framework branches. The lowest branch should be 40-60 cm. off the ground.
Care and management of non-bearing and bearing trees:
- Weeding. Weeds compete with the seedlings for nutrients, sunlight and water. Weeds must therefore be removed regularly or as the need arises. Avoid covercrops to creep around the base of the tree.
- Mulching. Mulching prevents the growth of weeds, and help conserve soil moisture and serve as source of organic matter when decomposed. During rainy season, however, mulch should not be placed to close to the tree because it is conducive to fungus.
- Intercropping. Intercropping is done to maximize land use. Banana (lakatan, latundan) intercrop can serve as windbreak, shade and source of early income.
- Irrigation. For sustained fruit production, it is important to water the pummelo before flowering and until after harvest to supplement rain. Pummelo plants are moisture sensitive during flushes of new growth, flowering, fruit setting, and fruit enlargement. As a practical guide for irrigation, watering should be done when 20-30 cm of the top soil is dry.A matured pummelo requires 100-200 liters of water per day especially during flowering, fruit setting and enlargement to a month before harvest.
- Pruning. Diseased and non-productive branches and water sprout using bolo, pruning shear or pruning saw must be pruned. All pruned surface must be painted to minimize entrance of micro-organisms and enhance healing. It is preferably done after harvesting.
Fertilizer Application and Management
1. Soil and Tissue Analysis
Soil and tissue should be collected and analyzed to determine the amount of fertilizer that will be applied. It is the most reliable way to determine the fertilizer requirements of pummelo.
Concentration of minerals found in branches, leaves and fruits of pummelo.
Elements Plant Parts
- Fruits Leaves Branches
- Nitrogen 2.0% 2.6% 1.2%
- Phosphorous 0.2% 0.18% 0.17%
- Potassium 2.0% 1.00% 0.75%
- Calcium 0.8% 4.2% 1.8%
- Magnesium 0.15% 0.25% 0.28%
2. Kinds of fertilizer
a.) Organic fertilizer
Fertilizer materials that came from living things. It can be animal manures or decomposed plant and animal bodies. This fertilizer material can:
- Improve soil structure and non-toxic to the root
- Improve soil aeration that encourage root elongation.
- Contain less nutrients
b) Inorganic fertilizer
- materials from weathered rocks plus the nitrogen coming from the atmosphere.
- granular from that contain on inert material called carrier.
- It contributes 80% I the soil mass
- Crop response in noticeable after a week
- Less bulky and easy to apply but expensive
- Makes the soil acidic, especially N fertilizers
- Toxic to the roots if applied in very high rates
3. Time of Fertilizer Application:
- Apply fertilizer when there is a sign of shoot growth.
- The recommended fertilizer levels should be applied in 2-3 installments; at the onset of rainy season, middle of rainy season, and towards the end of the rainy season
- Fertilizer are applied by digging holes around the tree within the area covered by the canopy.
- Fertilizers applied should be covered with soil to minimize surface evaporation and to prevent soil erosion.
- Maximum efficient utilization of fertilizer was found in 20-30 cm deep and 100-150 cm from the trunk of matured pummelo trees.
- Foliar fertilizer can be applied to supplement the soil applied fertilizers.
- It was found that Potassium applied on foliage increases fruit size and sugar content of the fruit.
- Foliar fertilizer are applied at 40 days after fruit set (DAFS); 60 DAFS; and 90 DAFS
4. Nutrient Deficiency Symptoms
1. Nitrogen (N)
- retards enzymatic activities and vegetative growth
- Yellowing of foliage
- Twig die-back
2. Phosphorus (P)
- Retard fruit development
- leaf and fruit abscission
- rough fruits
- thicker rind
3. Potassium (K)
- small fruit size
- immature fruit splitting (rind disorder)
- low sugar and acid content
4. Calcium (Ca)
- Breaking of branch
- short shelf life of fruits
5. Magnesium (Mg)
- yellowing of foliage
- reduce photosynthesis (low yield)
6. Zinc (Zinc)
- Smaller leaves
- chlorotic leaf spot
- twig die-back
- small size of fruits
7. Manganese and Iron (Mn and Fe)
- Small size leaves
- yellow color of leaves
- low fruit setting
- small size fruits
Part 1 | Part 2 | Part 3