1. Postharvest losses of fruits and vegetables in Pakistan are around 35% due to diseases, physical injuries, and improper storage conditions. 2. The main causes of postharvest losses are fungi, bacteria, insects, mechanical damage, temperature fluctuations, and improper storage. 3. Efforts are being made at both federal and provincial levels to minimize postharvest losses through improved harvesting and handling practices, pest and disease management, and infrastructure for storage and transportation.

2. By Allah Dad Khan
Present Situation of Post Harvest
Losses in Fruit and Vegetables

3. Agro climatic condition of Pakistan
Agro-climatic conditions of Pakistan ranging
from tropical to temperate allow growing 40
different kinds of vegetables and 21 types of
fruits. Major vegetables grown in Pakistan include
potato, onion, chilli, melons, cucurbits, tomato,
turnip, okra and pea, whereas citrus, dates,
mango, guava, apple, banana, apricot, grapes,
almonds, peach, plum and pomegranate are the
main fruit crops. At present area under fruits and
vegetables is 0.995 million ha (4.3% of the total
cropped area) with the total production of 10.992
million tonnes

4. Magnitude of Post Harvest
In Pakistan the magnitude of post harvest losses
of vegetables and fruits is about 35%. Efforts are
being made both at federal and provincial level to
minimize these losses to safe guard the interest
of growers, processors, traders, retailers and
consumers

5. Postharvest losses
These losses may be caused by complete
wastage of the product or by lower prices due to
a reduction in quality. The cost of these losses is
also important as the value of the product
increases several fold from the farm gate to the
final consumer, so in dollar terms postharvest
losses are even more significant.

6. There are generally three main
causes of postharvest losses.
1. Disease caused by fungi and/or bacteria
2. Physical injuries due to insects, mechanical
force, chemicals, heat or freezing
3. Non-disease disorders resulting from storage
conditions that upset normal metabolism when
the product is rejected further down the marketing
chain .

7. Other factors of postharvest losses
In addition to genetic traits, environmental factors
such as soil type, temperature, wind during fruit
set, frost, and rainy weather at harvest can have
adverse effects on storage life, suitability for
shipping, and quality. Cultural practices may have
dramatic impacts on postharvest quality. Good
Agricultural Practices during harvest operations
and any subsequent postharvest handling,
minimal or fresh-cut processing, and distribution
to consumers must be developed.

8. QUARANTINE SERVICES
The primary role of the Quarantine Division is to
reduce postharvest losses in an effort to ensure
that all practices from production to export are
strictly adhered to. Any farmer or exporter found
violating the system is automatically suspended
for non compliance. Farms are therefore closely
monitored by the Quarantine and the Extension
Departments.

9. Losses in Storage
 The improper handling, packaging, storage and
ransportation may result in decay and production
of microorganisms, which become activated
because of the changing physiological state of
the fruits and vegetables. Fruit, due to their low
pH, higher moisture content and nutrient
omposition are very susceptible to attack by
pathogenic fungi, which in addition to causing rots
may also make them unfit for consumption by
producing mycotoxins

12.  Primary factors responsible for post-harvest produce
losses are: poor pre-harvest measures-- adoption of
poor production techniques (varieties with low shelf
life, imbalance use of nutrients, insect pest and
disease infestation and abiotic stresses; low tech
harvesting procedures-- non-application of
pre-harvest recommended treatments/practices,
harvesting at improper stage and improper care at
harvest; and post-harvest problems-- non-removal of
field heat, dumping produce, moisture condensation
causing pathogen infestation, packaging in bulck with
out sorting and grading of produce, improper
transportation and storage, and distant and time
consuming market distribution

13. .
 In order to preserve the produce quality different post-harvest
techniques are recommended for variety of produce. These techniques
include; hydrocooling, refrigeration & freezing, modified atmosphere
(MA) packaging, MA storage, control atmosphere storage, skin coating,
hypobaric or low pressure storage, irradiation, dehydration, canning,
high pressure processing and pulsed electric fields and pulsed light
applications. In order to promote horticultural industry in Pakistan,
standardization of pre-harvest and post-harvest management
technologies minimizing postharvest losses and to enhance foreign
exchange earning to the maximum extent are therefore essentially
required for necessary adoption. At present various R&D institutions are
working on different aspects of postharvest management of vegetables
and fruits.

14. ADVANCES IN POSTHARVEST
TECHNOLOGY AND RESEARCH
 Selection of varieties for better shelf life
 Vegetable varieties: Riogrande, Roma
AVRDC Cv. (tomato), NARC - 91 (onion), Medium
Long Green (chillies), Local Selections (cucumber)
and VIP (pea) have shown better transportation
quality and longer shelf life. In fruits; varieties: Begum
Jangi (date palm), Cardinal, Flame Seedless
(grapes), Local Selections (fig), Sultan (pomegranate)
and ARS (N) Mingora No. 7, No. 8 & No. 9 (peach)
were found high yielding with longer post-harvest life.

15.  Influence of rootstocks on postharvest quality of some apples
 Studies carried out at Deciduous Fruit Development
Centre, Sariab, Quetta revealed that on rootstock MM 106, apple
cultivars (Red Delicious, Golden Delicious, Star King Delicious
and Spartan) showed better performance than on M-9 rootstock
for fruit texture and soluble solids. On the basis of organoleptic
evaluation or consumers' acceptability' MM-106 showed partially
better performance than M-9. For skin colour of fruit, rootstock
M-9 showed better results over MM-106. However, rootstock
MM-106 should better performance in terms of fruits texture, total
soluble solid contents and consumers' acceptability over M-9
rootstock.

16.  Pre-harvest application of fungicides
 Pre-harvest application of Benlate 50
WP minimized mold growth and increased shelf
life of citrus (Kinnow Mandrin) at ambient storage
temperature.

17.  Pre-harvest application of growth hormone
 GA3 when applied @ 20 ppm on grape Cv.
"Kishmish" not only increased the berry size, yield,
protein, reducing & non-reducing sugars, pectin and
ascorbic acid but also, the mineral contents of berries
(sodium, calcium magnesium and iron contents) were
increased hence improved the quality of fruits and
also its postharvest longevity.

18.  Postharvest application of calcium chloride
 Freshly harvested tomato fruits of
variety" Nagina" when dipped in 4% CaCl2
solution and kept at 15oC maintained marketable
quality upto 16 days

19.  Studies on degreening of citrus and mango
 Studies on degreening of citrus and
mango showed that citrus variety "Salustiana" stored
at 30oC and 85-90% RH (controlled atmosphere)
developed uniform colour after 24 hours, whereas in
case of variety "Honey Mandrine" there was a slight
colour development even after 36 hours. In case of
mango variety "Chaunsa" stored at 17oC and 80-85%
RH after chilling resulted uniform colour development
and produced natural flesh taste.

20.  Studies on wax coating materials
 Wax coating studies are being carried out
to make the produce more attractive with better shelf
life. Carnauba based surface wax increased shelf life
of Kinnow 3-4 weeks by delaying senescence. Edible
film coatings with gelatin (4%), corn starch (3%),
HPMC (3%) and stearic acid (1.5 to 3%) composition
enhanced storage life of carrots variety, "T-29" upto
45 days with minimum (10-15%) post-harvest water
loss

21.  Studies on potato storage
 Autumn potato crop is the main crop grown in the plains of Punjab. The crop is harvested during
the month of January. The produce is kept in the field until the end of February because of low temperature.
Thereafter, potatoes are mostly stored in the field in ordinary storage structures, where weight loss, rotting
and sprouting of tubers deteriorate the quality of produce. In cold storage the produce is held at 4-5oC. At
this temperature starch is converted to sugar and therefore potatoes become sweet. Also, because of high
charges of electricity this costs much higher as compared to ordinary storage conditions or storage of
potatoes at relatively higher temperature. Studies associated with these problems reveal that:
 1. Improved low cost on-farm storage structure (where hot air is replaced by cool air during night using
electric fan) the inside temperature was observed 3-4oC low and the stored potatoes retained marketable
quality upto 90 days.
 2. The sprout suppressant, "Camptothecin" when applied (sprayed) @ 0.5 mM inhibited sprouting
of tubers upto 45 days at 39oC, whereas in untreated control sprouting started after 30 days at 39oC.
 3. The sprout suppressants CIPC @ 1500 ppm and 2000 ppm, IPC @ 1500 IPM and 2000 ppm
and DECCO - 276E (combination of CIPC and IPC) @ 4.4 ml/100 ml water spray checked weight
loss, sprouting and sweetening when potatoes were held at 5oC and 9oC storage temperatures and 90% RH
until 105 days.
 4. Quality of potato tubers when held at 5oC or 9oC and 90% RH was retained until 60 days as the
weight loss, rotting, sprouting and sweetening were checked.

22.  Studies on tomato fruit storage
 In case of tomato, variety "Nagina" when
dipped in 4% CaCl2 solution and kept at 15oC
maintained marketable quality upto 16 days.

23.  Quality preservation of apricots
 Apricots when dipped @ 3% solution of
potassium meta bisulphite for 3 hours and then
dried proved to be successful.

25. Actors Problems (in order of
importance
Desirable
solutions
Producers
1- Lack of irrigation
infrastructures
2- Poor access to markets/high
competition of imported products
3- Lack/insufficient access to
credit
4- Poor access to treatment
chemicals and seeds
5- Insects and nematodes
6- Lack of skilled workers
(training)
7- Transport and storage
1- Implementation
of performed
infrastructures for
irrigation
2- Credit
3- Proximity and
availability of
treatment
chemicals and
seeds
4- Well trained
workers
Traders
1- Poor access to credit
2- Poor access to markets
3- Lack of traders association
4- Transport and storage
1- Access to credit
2- Training for
producers on use
of inputs (fertilizers
Focus group

26. Suggestions
 Improved access to high quality seeds (variety shelf life) and other inputs
 Training of producers on appropriate use of fertilizers and pesticides, the
appropriate marketing and production planning methods
 Improved transport practices, packaging technologies (eg: using folding plastic
boxes), improved storage infrastructures
 Improved access to credit and improved providing policy makers subsidies to
producers
 Training traders on effective and efficient transport or storage practices
 Monitoring of mycotoxins and pesticides residues