This field study conducted in Burundi shows the genetic variability of potato crop when exposed to temperature increase.

1. EFFECTS OF TEMPERATURE ON IN SITU GROWTH
AND DEVELOPMENT OF CIP POTATO CLONES IN
BURUNDI
D. Harahagazwe, J.F. Ledent and G. Rusuku
8th African Potato Association Conference
Cape Town, South Africa
6 – 9 December 2010

2. INTRODUCTION

3. Zoom on Burundi
• Inland country
• 27834 km2
• 8,17 millions inhabitants
• Density: 294 inhabitants/km2
• Pop. growth rate: 3,9 %
• Life expectation: 45 years
• GNR: 100 $/inhabitant/year
• Agriculture: 90,6 % of land
• Agriculture: 34,8 % of GDP
• Food insecurity (67%)

4. 4
Four scenarios
– Increase productivity (clean seed, fertilizers and
pesticides)
– Promote importation of ware potatoes (ex. 6000 t/an
from Rwanda)
– Introduce potato crop in warm areas (Imbo – region >
5000 ha)
– Different combinations of the three other scenarios

6. Challenges
• Potatoes as a temperate crop
• Cropping temperatures : 5 à 25°C
• Max. temperature: 28°C
• Variety tolerance: 30°C
• Imbo as warm tropical climate: >28°C/18°C

7. Temperature in Lowlands (Imbo region)
Mugerero 2005
Time (day number)
200 220 240 260 280 300
Dailytemperature(°C)
14
16
18
20
22
24
26
28
30
32
34
Minimum
Maximum
Average
Mugerero et Mparambo (2006)
Time (day number)
180 200 220 240 260 280 300Dailytemperature(°C)
15
20
25
30
35
Minimum, MUG06
Minimum, MPA06
Maximum, MUG06
Maximum, MPA06
Average, MUG06
Average, MPA06

8. Expected effects of temperature
• Total biomass reduction (stomatal
conductance)
• Harvest index reduction (hormonal action)
• Incidence and severity of pests and
diseases (disease triangle)

9. Specific objectives
– Determine temperature effects on the different
potato agrophysiological parameters
– Determine the phenotypic behavior of CIP
material in heat conditions

10. MATERIALS AND METHODS

11. TEAM WORK

12. Experimental sites and years
Parameter Gisozi Ryansoro
Season Dryseason Dryseason
Latitude (S) 3°34’ 3°47’
Longitude (E) 29°41’ 29°46’
Altitude (masl)
a 2091 1833
Globalradiation
e
(MJ.m
-2
.j
-1
)
9.06 -
Type of soil Peatland Peatland
8.63 8.63
Hygroxero-
ferrisol
d
Mparambo Mugerero
Dryseason Dryseason
2°50’ 3°15’
29°04’ 29°18’
892 801
Sites:
Lowlands: Mugerero and Mparambo
Highlands: Ryansoro and Gisozi
3 years: 2005, 2006 and 2007

13. Material, design and crop
management
• Genotypes:
• Clones: CIP01 to CIP05,
• Varieties: NDINA (Ndinamagara), RUHA (Ruhanyura) and
VICTO ( Victoria)
• Design:
RCBD (3 - 4 reps; 80 cm x 30 cm; 20 to 30 plants/plot
• Crop management:
• 2 t of lime/ha
• 500 g of cow manure/hill
• 14,3 g of NPK/hill, equivalent to 100-150-100 NPK formula

14. Data collected
– Plants emerged
– Ground cover
– Plant height
– LAI
– SLA (ImageJ technology)
– Pests and diseases
– Fresh and dry weight of
leaves at harvest
– Fresh and dry weight of
tubers at harvest
– Harvest index
– Tuber size and weight
– Dry matter concentration
– Etc…

15. Data analysis
• 2 levels of analysis :
– Per site and per season (environment): ANOVA
(Gomez and Gomez, 1984)
– Across environments: AMMI (Additive Main
effects and Multiplicative Interaction Model)
(Gauch, 1992)
∑ +++++= n gergeengnneggerY ερηζλβαµ
ANOVA PCA

16. RESULTS AND DISCUSSION

17. Statistics
Parameter Environment (E) Genotype (G) G x E
Dry matter
concentration
*** *** ***
Emergence rate *** *** NS
Plant height ** *** ***
Ground cover *** *** NS
Tubers/plant *** *** **
Proportion of
consumer tubers
*** *** NS
Average tuber
weight
*** *** *
Fresh tuber yield *** *** ***
Dry tuber yield *** *** ***
Harvest index *** *** ***

18. Tuber number per plant (ANOVA)
Site
G
IS07
R
YA07
M
PA07
M
PA06
M
U
G
06
M
U
G
05
Numberoftubersperplant
0
10
20
30
40
Mean
CIP01
CIP02
CIP03
CIP04
CIP05
NDINA
RUHA
VICTO

19. Tuber number per plant (AMMI)
VICTO
CIP01
RUHA
RYA07
NDINA
MUG05
CIP05
MUG06
MPA07
GIS07
CIP04
CIP03
CIP02
MPA06
25
2
20
0
15
-2
10
-4
5
Tuber number per plant
1
-3
30
-1
IPCA1

20. Dry tuber yield (ANOVA)
Site
G
IS07
R
YA07
M
PA07
M
PA06
M
U
G
06
M
U
G
05
Drytuberyield(t.ha-1)
0
2
4
6
8
10
12
Mean
CIP01
CIP02
CIP03
CIP04
CIP05
NDINA
RUHA
VICTO
7.5
2.1

21. Dry tuber yield (AMMI)
VICTO
CIP01RUHA
RYA07
NDINA
MUG05
CIP05
MUG06
MPA07
GIS07
CIP04
CIP03
CIP02
MPA06
7
0.5
6
-0.5
5
-1.5
432
1.0
Dry tuber yield (t/ha)
8
-1.0
9
0.0
IPCA1(SQR(t/ha))

22. Harvest index (ANOVA)
Site
G
IS07
R
YA07
M
PA07
M
PA06
Harvestindex
0,0
0,2
0,4
0,6
0,8
1,0
Mean
CIP01
CIP02
CIP03
CIP04
CIP05
NDINA
RUHA
VICTO
0.77
0.54

23. Pests and diseases
• Highlands:
– Late Blight (clone CIP03 and CIP04)
– Bacterial Wilt
• Lowlands
– No Late Blight observed (> 22°C)
– Mainly Fusarium (Wilt and Rot) especially clone CIP02 with 25% of
plant wilt
– Few plants with Black Leg/Soft Rot
• All sites
– Alternaria
– Aphides

24. LESSONS LEARNT

25. Ecology
– Average temperature:
– Cycle length:
– Dry tuber yield:
– Fungal diseases:
– Bacterial diseases:
Conditions for potato
cropping
Cool Warm
17°C 25°C
Long Short
11.6 t/ha 2.1 t/ha
Late Blight Fusarium
Bacterial Wilt Black Leg/Soft
rot
Optimal Sub optimal

26. However, the genetic variability was
expressed in warm climates:
– 3 clones (CIP01, CIP03 and CIP05) found
heat tolerant
– High potential for
• Current tropical and subtropical warm areas and
• Current cool but heating up areas due to climate
change

27. THANK
YOU VERY
MUCH
MUITO
OBRIGADO
MURAKOZE
CANE
MERCI
BEAUCOUP
Contact: dharahagazwe@yahoo.fr