THE POTATO CROPDieudonné Harahagazwe
Kadahenda, April 28, 2016
Integrated Potato Crop Management Course
Outline
�Potato history
�Gene bank and diversity
�Importance of potato crop
�Crop growth and development
�Potato production factors
�Yield gap
�Take-away message
I. POTATO HISTORY
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Equator
Tropic of Cancer
Tropic of Capricorn
Indian Ocean
Atlantic Ocean
Pacific Ocean
Pacific Ocean
Antarctic Circle
Arctic Circle
Osaka Tokyo
Delhi
Paris
Cairo
London
Taipei
Moskva
Manila
Tehran
Bombay
Berlin
Chicago
Bangkok
Karachi
Jakarta
BeijingNew York Istanbul
Calcutta
Shanghai
Hong Kong
Sao Paulo
Los Angeles
Mexico City
Philadelphia
Buenos Aires
Rio de Janeiro
Saint Petersburg
16th
century
LakeTiticaca
Potato
origin
20th
Century
II. GENEBANK (CIP – Lima, Peru)
• The world’s largest in vitro genebank which maintains
clonal and seed collections for over 100 years.
• Over 21,000 accessions of potato, sweetpotato, and
Andean root and tuber crops
Diversity of potato tubers
III. IMPORTANCE OF POTATOES
• Third important food crop in the world
(380 million t/ 19 million ha in 2014 -
FAOSTAT)
• High yielding ability (100 t/ha)
• One of the major cash crops in SSA,
including Rwanda
Top 10 Potato Production countries in
Africa (FAOSTAT)
Rank Country
1 Egypt
2 Algeria
3 Kenya
4 South Africa
5 Rwanda
6 Morocco
7 United Republic of Tanzania
8 Nigeria
9 Angola
10 Ethiopia
Nutritional values of potatoes
Fast food at Mombo, Tanzania
One medium size tuber (150 g) may
contain:
• Potassium : 620 mg – more than a
banana
• Vitamin C: 45% of daily requirement for a
man
• Dietary Fiber : 13% of daily requirement
for a man
• Healthy food: Lack of fat, sodium and
cholesterol (major heath problems)
10
IV. CROP GROWTH AND
DEVELOPEMENT
Solar
Radiat
ion
Temperature
Water
CO2
Light interception and
utilization
Importance of canopy cover for plant – light
interactions: Example of tea plantation vs tea
factory (Kadahenda, Rwanda)
Growth Cycle in 4 phases
Phase 1
Planting Germination
Germination Tuber initiation
Phase 2
Tuber initiation End of leaf growth
Phase 3
End of leaf growth Plant death
Phase 4
(t/ha)
Time
(days) 30 45 80 120
1 2 3 4
90 DAP
40
30
Leaves
Tubers
The 4 potato phases in a graph
DAP are indicative
Yield
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Why potato is tuber and NOT root
crop? …..because of STOLONS!
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Role of stems in potato productivity: stolons are formed
from stems
Group 1: Defining Factors
• CO2
• Radiation
• Temperature
• Plant characteristics
�POTENTIAL YIELD
(ex. 60 t/ha)
V. POTATO PRODUCTION FACTORS
Group 2: Limiting Factors
– Water
– Nutrients (N-P-K mainly)
Defining Factors
+
Limiting Factors
ATTAINABLE YIELD
(ex. 45 t/ha)
Group 3: Reducing Factors
– Weeds
– Pests
– Diseases
– Pollutants
Defining Factors
+
Limiting Factors
+
Reducing Factors
ACTUAL YIELD
(ex. 5 t/ha)
VI. YIELD GAP
• Yield Gap (Yg) = Potential Yield (Yp) –
Actual Yield (Ya)
• Yg is extremely high in SSA compared to
developed countries
• Yg can be significantly reduced by
addressing identified gap drivers
VII. TAKE-AWAY MESSAGE
� Clean seed
� Fertilizers
� Chemicals (pests and diseases control)
3 entry points for a successful
productivity:
Acknowledgements
We would like to acknowledge Humidtropics and the CGIAR Fund Donors
for their provision of core and project-specific funding without which this
research could not deliver results that eventually positively impact the lives
of millions of smallholder farmers in tropical Americas, Asia and Africa.
This presentation was made at a training workshop on Integrated Potato Crop
Management organized by the International Potato Center (CIP) for Innovation
Platform (IP) members of Kadahenda, Rwanda.