Transcript Assessment of post harvest losses on fresh vegetables

A commodity system analysis to reduce post harvest
losses of vegetable
Realized by:
KODJOGBE Guy, Chantal Pali, Nana Fredua AGYEMAN, Marian
ASAMOAH,Christophe Kouame, Benoit Gnonlonfin, Kerstin HELL,
Ousmane COULIBALY
Background

Fresh vegetables production provides employment
for nearly 60,000 people in Benin (PADAPA, 2003)

It was estimated that between 30 and 40% are
produced for own consumption (Hounkpodote and
Tossou, 2001)

In Kumasi (Ghana), 37 percent of the population
reported farming as their main occupation, and this
is particularly so for women (Brook and Davila,
2000 in Gundel, 2006)
Background

Fresh fruit and vegetables production is
confronted with a lot of difficulties:
- the ownership problem
- lack of technical training for producers
- poor access to credit and inputs
- distribution and marketing difficulties
- the high competition between local
products and imported products (Deguenon,
2006).
High losses have been reported for African countries
ranging between 15%–30% of the harvested
product (Buys and Nortje, 1997)
Objectives of study

Post harvest losses (physical and economic)
assessment on tomato, fresh pepper, dried pepper,
lettuce and okra

Identification of post harvest losses causes and
destinations.

Identification of mycoflora which accelerate the
fresh vegetables losses
Methodology

4 methods are applied in order to assess post harvest losses on these
vegetables value chains.
Product
Study zone
Focus group
Benin
Ghana
Tomato, Lettuce, fresh pepper
Tomato, Lettuce, fresh pepper,
dried pepper and Okra
Grand-Popo, Cotonou, Porto-Novo
Accra
Inventory problems occur by producers: (1group/zone) and traders
(3groups/zone)
Survey
Losses (phisical and economic),
Losses (physical and economic), causes
causes and destinations
and destinations according producers
according producers (60) and
(60) and traders (180) perceptions
traders (180) perceptions
Laboratory
analysis
Dilution method (speck, 1976): 30 samples/product/zone
Recording (morning, noon and
afternoon)temperature under shed
Tracking samples and temperature inside the baskets
daily weighting and counting the
samples
Methodology

Tracking samples:
- Assess post harvest losses both quantitatively and
qualitatively according to exposition temperature at market
- 6 baskets per product (1.5 kg) are chosen per trader (6)
- We have recorded the temperature under the shed and
and the temperature inside the baskets at regular
intervals time during morning, noon and afternoon.
- Daily, we have weighted the baskets and have counted
the number of spoiled products;
- This method is applied during 5 days for tomato, 7 days for
chilli pepper and 3 days for lettuce according to their
traders purchase frequencies.
Methodology
 Quantitative losses = Quantity of harvested or
bought products – Sold quantity of products

Qualitative losses depend on product grade, the
storage time and price.
Results and discussion
Focus group
Actors
Producers
Traders
Problems (in order of
importance
Desirable
solutions
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
1- Poor access to credit
2- Poor access to markets
3- Lack of traders association
4- Transport and storage
5- Insects and fungi
1- Access to credit
2- Training for
producers on use of
inputs (fertilizers
and pesticides)
Results and discussion
Table 1: Producers education level, training and association membership in Benin
Education
Crops
Education level
Training
Association
yes
yes
no
Effectif
total
Yes
no
primary
secondary
High
school
no
Tomato
20
80%
20%
35%
30%
10%
55% 45%
40%
60%
Chilli
pepper
20
75%
25%
45%
25%
5%
70% 30%
65%
35%
Lettuce
20
90%
10%
50%
40%
0%
70% 30%
70%
30%
Results and discussion
Table 2: Distribution of producers by education level, training and
association membership in Ghana
Education
Education level
Training
Association
Effectif total
Yes
45
High
No Primary Secondary school
95.6% 4.4% 27.4%
60%
Yes
No
Yes
1.1% 37.8% 62.2% 100%
No
0
Results and discussion

Causes of post-harvest losses of fresh
vegetables in those countries:
- use of local or auto-propagated seeds
- excessive use of fertilizer,
- poor irrigation system
- poor harvesting practices,
- supply exceeding demand
- Handling: poor transport and storage
- Insects and fungi
Results and discussion
Grade 1
firm and fresh; infestation rate<=5%; red-green (tomato and chilli), green (lettuce), Too
expensive according to the seasons.
Grade 2
Less firm and less fresh; infestation rate between 15% and 20%; red
(tomato and chilli), green with infestation (lettuce is throw away); the
selling price fall gradually.
Results and discussion
Grade 3
poor quality; infestation rate >= 50%; red (tomato and chilli); discount and sold to
street food traders
Grade 4
very poor quality; infestation rate = 100%; red (only the tomato); very discount and
sold to street food traders
Results and discussion

Destinations of the post harvest losses:
- Spoiled products are left on the field
and sold to street food vendors (more
common)
- Seeds from spoiled products can be
used for the next season
- Spoiled lettuce are given to pigs or
sold to breeders
Results and discussion
Table 3 : Quantitative losses assessment in value chain (%)
Countries
Benin
Products
Collectors
Wholesalers
Retailers
Collectors
/wholesalers
Tomato
12
8
12
10
20
13
fresh
pepper
-
13
4
-
-
4
Lettuce
-
22
9
-
-
16
Tomato
2
45,62
39,75
Fresh
pepper
Ghana
Dried
pepper
1.07
1.51
37.22
32.07
Lettuce
31.75
31.63
Okra
5.28
17.86
31.94
22.3
Collectors Wholesalers
/retailers
/retailers
0.92
Results and discussion
Table 7: Mycoflora occurrence on vegetables (CFU/g) in Benin
Fungi
Aspergillus niger
Aspergillus flavus
Rhizopus. stolonifer
Fusarium. verticilloides
Fusarium. prolifératum
Fusarium. oxysporum
Penicillium. citrinum
Penicillium. commune
Products
Grand-Popo&Come
Porto-Novo&Cotonou
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
Chilli pepper
Lettuce
Tomato
98.33 ± 254.22
2.22± 16.61
91.95 ± 197.49
0
2.27 ± 10.47
0
222.22 ± 463.80
0
0
0
0
0
48.31 ± 164.36
0
2.22 ± 14.82
0
123.33 ± 1054.58
26.67 ± 57.18
1.67 ± 15.81
56.06 ± 169.90
0
21.11 ± 70.30
1501.11 ± 1875.55
377.22 ± 739.84
68.33 ± 310.71
34.44 ± 105.90
96.11± 191.86
2.25 ± 21.20
125.00 ± 616.68
45.00 ± 99.45
0
0
Results and discussion
Table 8: Mycoflora occurrence on vegetables (CFU/g) in Accra (Ghana)
Products
Aspergillus
flavus
Aspergillus
niger
Aspergillus
ochraceus
Aspergillus
penicilloides
Fusarium
verticilloides
Fusarium
proliferatum
Penicillium
citrinum
Penicillium
spp
0
0
17.47±7.119
0
11.3±5.766
0.34±0.342
0
80.56±24.257
0
1.39±1.389
1.39±1.389
Fresh
pepper
108.56±30.023 91.44±16.048
Dried
pepper
30.56±13.255 27.78±8.320 23.61±14.704
Tomato
Lettuce
Okra
8.33±7.448
3.7±2.594
0
0
27.78±15.787
8.33±8.333
2.78±2.055
0
2.00±2.000
87.33±22.079
0.67+0.667
0
86.67±20.910 13.51±8.458
21.33±6.790
1.33±0.936
0.41±0.407
84.15±14.956
0
42.28±15.185 72.36±15.437
0
54.88±14.203 0.81±0.573
Results and discussion
Tracking samples : tomato case
Tomato baskets weight and percent of spoiled tomatoes depend on display
temperature
Conclusions

Post harvest losses are highest for tomato and lettuce, it can
reach up to 20% after 5 days

Chilli pepper and okra are the fresh vegetable which are most
infected by fungi in both countries: risk of mycotoxicosis

The main perceived causes of post harvest losses have their root
at producer level:
- use of local seeds/ auto-propagated seeds
- excessive use of fertilizers and pesticides: pesticide
residues
- poor harvesting practices

Poor handling (practices, packaging, etc.) cause losses during
transport and storage
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