3rd Africa Rice Congress Theme 3: Rice processing and marketing Mini symposium: constraints to and opportunities for rice processing and marketing Author: Johnson

1. QUANTITATIVE & QUALITATIVE
POST HARVEST LOSSES OF RICE IN
AFIFE, A FARMINING COMMUNITY IN
THE VOLTA REGION OF GHANA
MK ABOAKYE NUAMAH, PNT. JOHNSON, A BUDU &
EO AFOAKWA

2. Introduction
Why and what was studied ?
•
Assessing postharvest losses of foodgrains is an important exercise in
helping to improve intervention
programs aimed at increasing farmer’s
productivity.
•
CIDA-AfricaRice Project- help farmers in
Afife to buy into the interventions to be
introduced
•
Quantitative
and
qualitative
postharvest losses in key unit
operations(harvesting,
threshing,
winnowing and drying) occurring the
rice value chain at Afife; an irrigated
rice farming community in the Volta
Region were investigated.
Fig. 1: Map of Ghana:
Showing Study Area
Afife
Afife

3. Main Studies
• Study 1: Assessment of famers’ perception and
knowledge of the causative factors of and
solutions for rice postharvest loss.
• Study 2: Assessment of the quantitative losses
during key unit operations-harvesting, threshing,
drying, winnowing and milling.
• Study 3: Assessment of the effect of harvesting
time on the qualitative losses during these unit
operations for the main rice variety at Afife (Togo
Marshall).

4. Study 1: Summary of causes of losses perceived by 125
respondents ( 80 males and 45 females)
Causes of post harvest loss
Storage pests
Frequency
(%)
5 (4)
Bad road network
1 (0.8)
Late harvesting
1 (0.8)
Field getting waterlogged or flooded during
harvesting times .
Poor harvesting by hired labourers
4 (3.2%)
Manual method of threshing is inefficient
10 (8%)
Spillage during winnowing
4 (3.28%)
Lack of better storage facilities
2 (1.6%)
25 (20%)

5. Causes of post harvest loss
Freq (%)
Rains during harvest times
1 (0.8%)
Shattering of over-dried rice
3 (2.4%)
Improperly threshed straws
6 (4.8%)
Inappropriate tarpaulin size for threshing
5 (4 %)
Inefficient harvesting method
11(9.02%)
Lodging
1 (0.8%)
Delays during threshing
6 (4.8%)
Spillage during threshing
18 (14.7%)
Labour-intensive threshing
2 (1.6%)

6. Study 1: Summary of solutions perceived by respondents
for each unit operation.
Stage
Solutions to rice post harvest losses
Harvesting
Mechanisation
Early harvesting
Threshing
Mechanisation
Early threshing
Drying
Early drying
Use of solar driers
Provision of well spaced drying floors
Ensure that rice is thoroughly dried
Storage
Provision of better storage infrastructure
such as use of silos
Fumigation of storage space
Immediate marketing
Regular cleaning of storage place
Chemical treatment of rice before storage
Application of rodenticides

7. Study 2- references of methods used
• Harvesting loss assessment (Badawi, 2003)
• Threshing loss assessment
• Winnowing loss assessment
• Drying loss assessment (Appiah et al., 2011)
• Storage loss assessment (Harris and Lindbald,1978)
• Milling loss assessment (IRRI, 2009)

8. Sickle Harvesting
Reaper harvesting
Combine harvesting
Fig. 2: Harvesting Methods Assessed

9. Results of Study 2- Losses during Harvesting
There was no significant
difference between methods
of harvesting but significant
differences existed among
farmers at p≤0.05.
Interaction between farmers
and method of harvesting
was also not significant at
p>0.05.
This means improvement of
farmers harvesting practices
could help reduce losses
considerably irrespective of
the method used.
losses estimated in this
study exceeded loss ranges
of 1-3% reported for South
East Asia (IRRI, 1997).

10. a. Mechanical threshers
b. Manual threshing (bambam)
Fig. 4:Threshing Methods Assessed

11. Results of Study 2-Losses to Threshing
Rice losses due to threshing
methods used in the community
differed significantly (p≤0.05) for
spilled and re-threshed losses
Interaction for methods and
farmers were significant for rethreshed losses (p ≤0.05) but
losses to spillage were similar.
WBT losses reported in this
study far exceeded loss (6.14%)
reported for Ghana by Appiah et
al., 2011.
Spilled losses (5.64%) and rethreshed (12.73%) losses reported in this
study exceeded what Malaysian workers observed during WBT. They
reported spilled loss of 1.13% and rethreshed losses of 11.7%. This
means some intervention programs are needed in this community.

12. Results of Study 2: Losses to Winnowing
Losses to both methods did not
vary from each other.
However, significant difference
existed among farmers during
winnowing (p≤0.05).
Interaction between methods
and farmers were found to be
significant
(p≤0.05)
during
winnowing.
Values reported in this study
were far below loss of 4%
reported
in
Philipines
by
Badawi (2003) and
2.5%
estimated in Madagascar.

13. Results of Study 2- Overall post harvest losses
Post harvest stage
Ranges of % Rice loss
Harvesting
2.82-7.29
Threshing
3.77-24.58
Winnowing
0.23-1.53
Drying
3.73-7.32
Storage
Total
Average
2.19-11.12
12.74-51.84
32.29
Total post harvest losses incurred in this study (12.74-51.84%) were not
consistent with losses of 10-40% reported by Satin, 1997 & FAO, 1997
However, average total post harvest loss in this study (32.29%) was
found within the estimated loss by (Satin, 1997; FAO, 1997)
From the study, it can be deduced that almost 33% of what farmers
produced at Afife never reach the market but is rather lost during the
post harvest chain.

14. Results of Study 3: Physical characteristics of milled rice
samples
Harves
ting
time
Daf 25
L (mm)
B (mm)
Shape
(L/B)
*TGWpaddy (g)
TGWmilled (g)
size
sha
pe
7.27±0.21a
1.75±0.08b
4.16±0.20d
25.36±0.24a
17.67±0.40c
L*
S*
Daf 30
7.23±0.40a
1.67±0.07c
4.34±0.22e
25.95±0.38a
18.07±0.12b
L
s
Daf 35
7.13±0.18a
1.72±0.08b
4.15±0.21d
26.78±0.34b
18.24±0.11b
L
s
In a column, means having same superscripts do not differ significantly at 5% level of probability. L*-long, S*-slender
Grain classification: 6.61-7.5 -long, >3.0 -shape (IRRI,1993), *TGW-Thousand grain weight
a, b, c
Grain length for all harvested rice at different dates were similar
but 30 DAF differed from DAF 25 and 35 for grain breadth (p≤0.05).
25 and 35 DAF had similar shape but 30 DAF differed from them
statistically.
All rice harvested at different times were long and slender
according to grain classification (IRRI, 1993).

15. • All grain types (paddy) were found to have
acceptable TGW (20-30g) according to AduKwarteng et al., 2003) but DAF 35 was
found to be more acceptable and different
from daf 25 and 30.
• All grain types were found to have
acceptable TGW of 16-20g for long milled
rice according to standards set by USA
regulation.
• DAF 30 and 35 recorded high TGW for milled
rice and differed statistically from 25 DAF.
• With this, we expect rice and rice products
such as flour to be higher when processed.

16. Mean chromameter and other physical properties of rice
Harvesting
time/attribut
e
L*
25 DAF
30 DAF
35 DAF
71.33±0.19a
68.05±0.16b
72.33±0.13c
a*
+1.62±0.14a
+3.75±0.09b
+1.82±0.07c
b*
+11.70±0.57a
+11.73±0.16a
+11.32±0.15a
Chalkiness (%) 0.03a
0.08a
0.29b
0.49a
0.10b
0.07b
0.13a
0.34b
1.14
0.02
Immature (%)
Mouldy (%)
Red rice (%)
0.04a
0.09
Rice types with same superscripts in a row are not significantly different at p≤0.05. L* = Lightness of kernel; a* = Redness of kernel; b*
=Yellowness of kernel
a,b,c
35 DAF harvested rice recorded the highest whiteness value and hence
would impact positively on consumers acceptability.
All the rice harvested met quality criteria (4% red rice, 6% chalky grains
and 2% immature grains) for market competitiveness (Codex Alimentarius,
1990).

17. Study 3: Effect of Harvesting time on physicochemical, cooking and eating
quality of rice (var. Togo Marshall).
•
Time needed to cook rice varied with
time of harvesting. Early harvested
rice (25 DAF) cooked at less time but
late harvested rice (35 DAF) cooked
at a higher time.
•
Harvesting at 30 and 25 DAF had
similar amylose composition but
differed for 35 DAF which was least.
•
Harvesting at 25, 30 and 35 DAF
varied extensively for ASV (p≤0.05).
However, gelatinization temperature
for 25 and 30 DAFs were classified
as intermediate while 35 DAF was
classified as high (Normita and Cruz,
2002).
•
Harvesting at 30 and 35 DAF
compared well for KER, WAR and
VER
but
differed
from
early
harvested rice 25 DAF.

18. Study 3: Effect of harvesting time on milling qualities of rice
Head rice yield, husking yield,
milling yield increased with
increasing time of harvesting but
decreased for broken grains.
Statistically, husking yield for 30
and 35 harvested rice differed for
25 DAF harvested rice (p≤0.05).
However,
30
and
35
DAF
compared well for milling yield,
milling degree, broken grains and
head rice (p>0.05).