Nendran the commercial plantain variety in Kerala occupies 50 % of the total area in the state & maximum quantity of the fruit is sold locally. Small quantity is exported to middle east , with target of large Indian community. Also due to separate AEZ in Kerala for Banana have boosted the export of plantain. Presently shipment carried out by air is constrained by the higher expenses involved. This protocol of sea shipment is prepared with the national & international references, where the practical trials have been conducted for the quality in shipment.
Nendran Varieties: Nedunendran, Chengalikodan and Attunendran & Nendran is grown throughout Kerala.Thrissur,Ernakulam,Malappuram,Calicut,Palghat ,Wynad are the prominent districts.
Pre Harvest Spray Requirements: Pre harvest spray of Sulphate Of potash before harvesting improves the shelf life of Plantain. Spray 1.0 or 1.5 % SOP before harvest. (FP- 91)
The maturity index must consistently meet two requirements. It should ensure:
For each week bananas harvested one week earlier than normal harvest age, the green life increases by 3-5 days.
Hands of 75 – 80 % maturity must be harvested .
Almost all damage caused to the fruit occurs during loading & unloading operations.Overhead cableways must be used in banana transport to packhouse. This is the most successful method of minimizing damage during the movement of plantain from the point of harvesting to the packing station.
The operation required for preparing & packing bananas for export will be the same irrespective of the type of structure .the operations include dehanding, washing, selection, & grading, fungicide application & packing.
Dehanding: Dehanding site should be close to the end of the wash tank.The bunches arrived other than cable way system, they should not be stacked on the ground , but immediately hung from an overhead structure at the correct height. Bunch is proximally hung with largest hand uppermost.
Dehanding must be done with a sharp chisel type dehanding tool, by leaving maximum crown attached to the hand. Crown should be cut evenly, other wise it’s outer finger may be detached.
The knife must be very sharp to give a clean, smooth cut in a single movement.
The separated hands must be spread on a clean surface to drain the latex for 10 minutes.
After drain of latex then hands must be placed immediately in the wash tank.
Washing: As soon the hands are drained from latex they are placed in the wash tank to remove the dirt & latex which exudes from the cut surface of the crown. There should be flow of water through the tank to avoid accumulation of dirt & fungi spores, which may infect the crown of hand. If there is no continuous fresh water supply, chlorine (@ 100 mg / lit active chlorine) & / or alum (@10 gm / lit) are normally added to recirculated water to remove the latex & destroy microorganisms. Dehanded fruit is washed for 4 minutes. Normally, the flow of the water should be from the dehanding end of the tank, so that the hands of plantains move along to the far end where workers select & grade them prior to fungiside application.
Quality Inspection at packing plant: An inspector checks for minimum finger length & caliper grade, as well as different types of damages, & marks the hands or whole bunches that have to be rejected. The selection procedure continues at the water tanks of the packing plant.
As the shipments of plantains is done with hands packed in fibreboard boxes, the principle postharvest disease problem has been crown rot. This develops from the infection of the cut surface of the crown tissue, which spread in to the fruit stalk.Fungi causing post harvest diseases of banana,
Most of the disease are occasional serious where infection levels are high & favourable conditionas occur.Al post harvest disease organisms are widespread in the field growing & sporulating on decaying banana flowers, bracts & leaves.The spores are blown by wind or splashed by rain on to the fruit & also carried on bunches to contaminate the packing station environment, including washing water.
Since most post harvest diseases of Plantain originate in the field from infected plant trash, plantain field hygine & regular disease control measures play an important role in post harvest disease management.In the field dead flower end must be removed when the plastic covers are placed on the developing bunches.Some farmers keep the flowers upto harvest if not removed spores of the fungus damaging plantain is carried in packhouse operation.
Fungicide treatment on the dehanded bananas: The most effective postharvest control of crown rot is provided by treatment with benzimidazole group of fungicides., those most commonly available being thiabendazole( 2-thiazol-4-yilbinzimidazole ) & benomyl [ Methyl -1 ( butylcarbamoyl) benzimidazole-1-yl carbamate ] . Thibendazole is available in the form of wettable powder & emulsifiable concentrates & benomyl as a wettable powder.Also Bavistin 500 ppm for 10 minutes is the best treatment.
Fungicide application is made after the hands of fruit have been washed, but they must first be drained of excess water. Especially when dipping is in small amounts of fungicide suspension, other wise water adhering to the skin of fruit may dilute the fungicide below its effective concentration.Since good coverage of the crown is necessary, stack the washed hands in perforated plastic trays to drain. Followed by fungicide application.
Drying : Hands are placed on cushioned , rotating drying table for air drying.
Seal fruit in polythene (polyethylene) bags. Plantains sealed in polythene bags remain green for a longer period.. As the fruits respire, the atmosphere within the bag decreases in oxygen and increases in carbon dioxide. Respiration is then inhibited because of the reduced oxygen. Plantain may be sealed individually, or several fruits may be bagged together. The plantains must be packed in a regular pattern in the box in such a way that the hands of fruit do not move & damage each other when the box is handled.
The pack should be full & tight enough to prevent the contents moving.
All plantains exported must be packed in double walled fibreboard boxes holding an average weight of 5 to 10 kg. These cartons must be lined with a polythene sheet of 100-guage thickness to help reduce moisture loss & 2 % ventilation. An ethylene absorbent KMnO4 must be used in a box to enhance the shelf life.
The plantain boxes are directly loaded on to pallets at the packhouses & the pallets be loaded on to refrigerated containers ( reefers ) , which are 20’ or 40’ insulated containers.. These reefers are then transported to the ship by road. The containers are transported by sea to the importing country & then by road directly to the ripening chamber. Plantains are shipped under refrigeration to prevent the initiation of ripening before they arrive at their destination.
Stacking boxes of fruit in ships holds or containers must be done with ensurance of adequate ventilation to all boxes. This is important in pallet transport because with a solid stack of boxes on a pallet the air will tend to go around it, leaving some of the boxes inadequately cooled.
Use stapling strips of fibreboard between pallets or use of inflatable bags jammed around the pallet.
Plantains must be both the boxes of fruit & the containers should be precooled & loaded very quickly, because many of the containers refrigeration units are designed only to maintain cool temperatures, not for the rapid removal of field heat.
Storage Temprature & Humidity to be maintain In Voyage
At refrigerated storage & transport temprature should be 13ºC & 90-95 % Relative Humidity.
Avoiding Ethylene In Transport
Reducing ethylene levels delays ripening. Using chemical ethylene absorbents or oxidizers, to reduce ethylene inside polythene bags, is a feasible method for extending storage life.
Ethylene can be absorbed by activated carbon, or oxidized by potassium permanganate, ozone, ultraviolet light, or the use of catalysts.
The simplest ethylene absorber consists of an inert carrier, such as vermiculite or rice hulm and ash, impregnated with potassium permanganate. Potassium permanganate absorbs free ethylene. Recently, Japanese researchers have made plastic bags coated with zeolites, which absorb both oxygen and ethylene. Zeolite use is at an early stage, but may eventually result in an appropriate technology for extending storage life of plantain .
Source: Mr Nanapure Sharad, Agriculture Expert, Nasik, Mob: 09555268379