Post Harvest Losses in Fruits and Vegetables,

 Their Extent and Methods of Control

 R. K. Shukla J. C. Royer
 Dominica Agricultural Marketing Board
 Roseau, Commonwealth of Dominica


 Post-harvest losses in fruits, vegetables, food crops and
other perishable commodities, if effectively controlled, could
feed millions of people now suffering from hunger and
malnutrition in many parts of the world. Probably the heaviest
losses occur in fruits and vegetables. Mature fruits and
vegetables are highly susceptible to invasion by specific
pathogenic micro-organisms. This is because they have a high
water and nutrient content. After harvest they are no longer
protected by the intrinsic factors which make them resistant
during their development on the plant. Growth cracks and
mechanical injuries during harvest, transport and storage are
also responsible for the losses. The losses vary between various


types of fruits and in different seasons of the year. The losses
in. the soft fruits during the summer months in a tropical
region would be far more than in winters in the same area. To
meet the world's current and future food demand many
developmental programs aimed at increased production and
population control have long been initiated all over the world.
In the recent years, the potential to control the post-harvest
losses has also been recognized as an effective means of increas-
ing the capacity of current level of production to feed the ex-
isting and the ever increasing population. There is now a bet-
ter appreciation of the problem both among producer and
consumer alike.


 If post-harvest losses in food crops and other perishable com-
modities were effectively controlled, millions of people now suf-
fering from hunger and malnutrition in many parts of the world
could be fed. Probably the heaviest losses occur in fruits and
vegetables. Mature fruits and vegetables are highly susceptible to
invasion by specific pathogenic micro-organisms, because they
have a high water and nutrient content. After harvest they are no
longer protected by the intrinsic factors which make them resis-
tant during their development on the plant.
 Growth cracks and mechanical injuries during harvest,
transport and storage are also responsible for losses. These losses
occur both in developing and developed countries but in dif-
ferent proportions. The losses also vary between various types of
fruits and in different seasons of the year.
 Many developmental programs, aimed at increased production
and population control, have been initiated all over the world to
meet the world's current and future food demand.
 In the recent years, the potential to control post-harvest losses
 has also been recognized as an effective means of increasing the
 capacity of current level of production to feed the existing and
 the ever increasing population. There is now a better appreciation
 of the problem among producers and consumers alike.

 Post-Harvest Losses Defined
 Although the demarcation line between the production losses
 and post-harvest losses is not very clearly drawn, the errors in
 distinguishing between the two are not great. The post-harvest
 losses have been defined as losses which occur between the time
 the fruit or vegetable is separated from the parent plant and
 when it is eaten. Fruit falling on the ground and left as such are
 also regarded as production losses. The same fruit is, however,
 regarded as a post-harvest loss if no market can be found. In con-
 trast, if for any reason the crop is not harvested, it is regarded as a
 production loss.

 Causes of Post-Harvest Losses
 Production of horticultural crops is far from factory operations
 where everything can be planned beforehand. Agro-climatic con-


VOL. XX-PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY


editions and other environmental factors like temperature, relative
humidity, level of fungus spores and the presence of other disease
carrying organisms, storage conditions, and care during handling
and transport determine the degree of post-harvest losses. These
losses should not be regarded as the inevitable price which must
be paid for produce, because proper application of the available
techniques can reduce post-harvest losses to a very low level.

Various Types of Post-Harvest Losses
 Growing quality fruits for export is much more than just plant-
ing trees and waiting for a rich harvest. A lot of skill is needed
both in production and in the preparation of the produce.
 As mentioned above, there could be many reasons to start the
deterioration process. They can broadly be classified into the
following categories:

Post-Harvest Losses Due to Physiological Factors
 Generally, horticulture is the most important production sector
in the Caribbean region, and therefore, the problem of post-
harvest losses has to be given important consideration.
 Fruits and vegetables continue their respiratory process even
after they are harvested. The rate of respiration very much
depends upon the environmental conditions prevailing after
harvest. The respiration is mainly an oxidation process which in-
creases the level of carbon dioxide and water and leads to the for-
mation of energy. This chemical energy is required to perform the
various essential catabolic and anabolic processes. After harvest,
the respiration process in fruits and vegetables is not very effi-
cient, as it is not backed up by the natural photosynthesis process
through the leaves. The fruits and vegetables, therefore, give off
energy in the form of heat, technically called "vital heat." Abnor-
mal physiological processes lead to serious losses in food value or
even non-parasitic diseases like bitter pit or scald of apples.
 Adverse atmospheric conditions after harvest, i.e., excessive
cold or heat, could be responsible for chilling or heat injuries in
fruits and vegetables. Rate of respiration can be controlled by
keeping the temperature within safe limits. Temperature re-
quirements vary considerably not only between species but even


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