Quality is a concern in all aspects of banana production, but harvesting and post-harvest stage is also most important.
Characteristics of Good Quality Hands
ü No or very few blemishes, spots or bruises;
ü No malformed or under developed fingers; and
ü No missing or cut-off fingers between existing fingers.
Harvesting
Time of harvesting
Banana harvesting depends on:
ü The distance where the fruit is to be consumed or marketed:
· For the local or nearby market: bananas should be harvested a few days before they ripen.
· For far-away markets: bananas must be picked less mature (but to attain natural sweetness, fruits must be harvested at a mature stage).
ü Processing: fruits that will be processed into chips can be harvested at an earlier stage than fruits that are intended for the fresh market.
Fruit maturity
The maturity of the fruits can be assessed from:
ü The fruit color and the angularity or fullness of the fingers
· For local markets or home consumption- Harvest when the fruits are fully filled and turning from green to yellow.
· For the far-away markets- Harvest the fruits when they are less mature, when they are still green with plainly visible angles.
· These indicators depend also on the variety as some are still angular even when fully mature.
ü The number of the days from flower emergence-color coding applied during bagging is helpful in the assessment of the maturity.
ü A combination of grade and fruit age- At a certain time after flowering, check all the bunches with the same color code and check the grade of the fruits with a caliper.
· When any of the three fingers in the center of the outer whorl of the 2nd hand from the top fail to enter the caliper or when they enter with difficulty, the bunch is ready for harvest
· The bunches that are not ready for harvest are checked again one week later.
· The 3rd week, the bunches are harvested anyway, regardless whether the fruits pass the caliper or not.
Harvesting Operation
In harvesting, it is necessary to follow these tips:
1. Avoid injury or damage to the fingers, since this leads to black patches and rotting afterwards.
2. In dry periods, don’t stop irrigating the plants at least one week before harvest, since it reduces fruit quality and shelf life.
3. Harvest the bunches preferably in the morning.
4. Harvesting is the best done by two persons- A “cutter’ who will cut the the pseudo stem and a “backer” who will carry the bunch:
· The cutter cuts the trunk slowly and partially at about 1/3 from the top, for the bunch to fall slowly.
· The cutter holds the tail end of the bunch before it touches the ground.
· The cutter then cuts the peduncle, leaving about 30 cm of the stalk for easy handling.
· The bunch is lowered on a shoulder pad on the backer.
5. Do not place the bunch on the ground or against a banana plant, to avoid bruising the hands.
6. Leave at least 2 m of pseudo stem standing for 1 to 2 months as a reservoir for water and nutrients for the following sucker.
7. Cut off the leaves that directly shade or obstruct the follower.
8. After 1 to 2 months, cut the old pseudo stem and leaves, chop lengthwise and crosswise into small pieces and use as mulch.
Post-harvest Care
Transport from field to packing house
· Bring the bunches or hands to a shaded area soon after harvesting in commercial plantations-aerial cables or tractor-drawn trailers are used to transport the bunches to the packing area. Small-scale banana growers sometimes de-hand bunches right in the field.
· Cover the fruits with leaves to prevent scalding by the sun.
· During dry periods, spray the bunches with water (pre cooling).
· Handle the bunches and fruits with care-leaves or plastic sheets can be used to cushion the fruits to minimize rubbing and bruising.
· Closely pack the bunches, so there is no space for shaking during transport.
· Ensure adequate ventilation during transport.
Deflowering, dehanding, washing, sorting and packing
These operations are done mainly for bananas intended for export, but also significantly improve quality of bananas for the local market.
· Remove the floral parts from the fingers, within 2 to 3 minutes before cutting the hands off the stem to keep the latex from drying and causing spots.
· In removing the hand from the stem, leave as much crown as possible to the hand.
· Carefully hold the detached hand.
· Carefully hold the detached hand by supporting the whole hand and not just holding one or a few fingers, which may break the neck.
· Carefully place the hands in the tank filled with clean water with 10 ppm chlorine (to keep the water free from bacteria).
· Make sure the hands do not strike against each other or the side of the tank.
· Wash off any dirt and spores of fungi adhering to the fruits.
· Transfer the hands to another tank, where they are selected and sorted.
· Separate fruits with bruises, scabs, scars and oversized, undersized or malformed fingers.
· Kalium aluminium sulfaat can be sprayed or sponged onto the fruits to control fungi and to prevent latex flow.
Packing
Bananas for local market should be packed in wooden crates, lined with newspapers or plastic sheets. Bamboo baskets should be avoided as much as possible, since they can easily be deformed, are unstable and have sharp edges that can damage the fruits.
Bananas for export should be packed in carton boxes with holes (2.5 cm in diameter) for ventilation. The boxes must have cardboard or foam at the bottom and lined with thin
polyethylene films. Hands must be separated by cardboard or foam to prevent bruising.
Storage
· Cooling the fruits in optimum storage conditions (13 to 14°C and 95% relative humidity) is the most effective way of prolonging shelf life, storing below the optimum temperature will result in chilling injury.
· Fruits may also be stored at ambient conditions with a modified atmosphere by:
¾ Sealing the fruits in polyethylene bags before packing them in cartons.
¾ Using ethylene absorbents in the boxes (clay-ash chips dipped in saturated potassium permanganate (KMnO4) at 2 chips per kg fruit).
Combination of low temperature and modified atmosphere increases the storage life more and minimizes the occurrence of chilling injury.
Embedding the fruits in moist sawdust (1 kg of sawdust mixed with 1.5 liters of water for 1 hand weighing 2 kg) can delay ripening by one month.
Ripening and Degreening
The optimum temperature for ripening is 25 ± 2°C. using ethylene helps in ripening bananas. There are two ways to use ethylene:
· It can be generated or released at a concentration of 500 to 1,000 ppm inside a closed room at a temperature of 25°C and 80 to 90% RH.
· It can be sprayed or be used to dip the fruits in 500 to 1,000 ppm, but leaves residue on the fruits.
