The risk of deterioration of produce
during transport can be reduced in several ways.
Trucks
used to transport fresh produce. Most fresh produce is now moved in road vehicles, with
lesser amounts by sea, air or inland waterways. The vehicles in most common use
are open pick-ups or bigger trucks, either open or enclosed. The use of road
vehicles is likely to increase, so users should give attention to the
following:
- closed vehicles without refrigeration should not be used to carry fresh produce except on very short journeys, such as local deliveries from farmers or wholesalers to nearby retailers;
- open-sided or half-boarded trucks can be fitted with a roof on a frame. The open sides can be fitted with canvas curtains which can be rolled up or moved aside in sections to allow loading or unloading at any point around the vehicle. Such curtains can protect the produce from the elements but still allow for ventilation. Where pilfering is a problem, the sides and rear of the truck must be enclosed in wire mesh;
- a second, white-painted roof can be fixed as a radiation shield 8 or 10 cm above the main roof; this will reflect the sun's heat and help to keep produce cool;
- for the ventilation of long-distance vehicles, more elaborate air intakes can be fitted in conjunction with louvres, to ensure a positive air flow through the load;
- refrigerated trucks or road, rail or sea containers may be used for long journeys, but the cost of such transport makes it uneconomical for small-scale operations.
Handling
and stowage practices.
Although the shape and condition of trucks are important factors in fresh
produce transportation, the loading and stowing methods in vehicles are
pertinent to damage and loss:
- the best loading factor must be achieved, that is the maximum load that can be carried economically under satisfactory technical conditions: a stable and well-ventilated load;
- the size and design of packages should give adequate levels of ventilation of contents with the minimum of wasted space, and the packages should be strong enough to protect the contents (Figure 8.2);
- loading and unloading of vehicles should be properly supervised to prevent careless handling of packages; loading aids such as trolleys, roller conveyors, pallet or forklift trucks should be used where possible to reduce the handling of individual packages;
- stowage should be carefully done to avoid collapse of the stow during transport; packages should not be stacked higher than the maximum recommended by the maker, otherwise the bottom layers may collapse under the weight of those above
- packed produce should be protected from sun and rain at all times including during loading and unloading (Figure 8.3);
- packages should be loaded on dunnage (pieces of lumber or slatted racks) on the beds of vehicles, or on pallets in order to allow the circulation of air around stacks during transport;
- if the load is to be distributed to several locations, packages should be loaded in reverse order to that in which they will be unloaded, i.e. last on, first off; at the same time the load should be distributed evenly on the vehicle.
Although
every care may be taken to observe all the above precautions, the standards of
driving remain a difficult problem to overcome. In many cases, drivers are
induced to speed in order to make more money for themselves or their employers.
Whenever possible, only experienced and responsible drivers should be employed.
Other
modes of transport. Fresh
produce is transported by many other means, from head-loads to air-freighting.
In all cases, the same conditions should be observed. Produce must be:
- kept as cool as possible;
- kept dry;
- moved to market as quickly as possible.
Rail
transport.
In some countries a large amount of produce is carried by rail.
The
advantages are:
- transport damage to produce while moving is slight as compared with that from haulage over rough roads;
- costs are lower than transport by road.
Rail
transport, however, requires extra handling since road transport is needed to
and from the rail journey; transport by road alone usually is a door-to-door
service.
Water
transport
Inland. Waterway transport is used in some
countries to move produce to markets. Much of the produce carried in this way
is packed in locally made crates or sacks. The vessels employed are often mixed
passenger-cargo craft, and no special handling is provided for fresh produce.
Sea. Short-distance transport of fresh
produce in small ships without refrigeration is common in countries of island
communities (e.g. the Philippines). Ships often accommodate passengers and
general cargo, and no special provision is made for fresh produce, which may be
stowed in unventilated holds. Losses are high, owing to rough handling by
porters, inadequate packaging and overheating in unventilated holds or near
engine rooms.
There
is much room for improvement in this mode of transport. A model for organized
and efficient sea transport is the refrigerated shipment of commercial crops
such as bananas, although a modest investment by the small-scale shipper could
greatly improve performance.
Air
freight. As
with shipping, the international trade in the air-freighting of high-value
exotic crops is generally well organized. In some countries where road links
are poor (e.g. Papua New Guinea), produce is carried by air from production
areas to urban markets. Costs are high and losses often heavy because of:
- poor, non-standard packages;
- careless handling and exposure to the elements at airports;
- consignments left behind in favour of passengers;
- flight delays owing to bad weather or breakdowns;
- intermittent refrigeration followed by exposure to high temperatures;
- relatively small produce shipments.
Even
though changes are made in packaging and handling, it is unlikely that the
overall situation will improve much until road links are established between
producers and consumers.