Presentation on cassava experiments on crop response to fertilization carried out in northern and southern Vietnam in 2016

1. Cassava Experiments and Results in
Vietnam in 2016
Jonatan S. Soto B.
j.s.soto@cgiar.org
7-19-2017
Palmira, Colombia

2. Outline
• Background
• Objectives
• Results (by location)
• Troubles with data collection
• Results
• Conclusions

3. Background
KM21-12
KM94
SM937-26
KM60

4. Background
Treatment
ID
Treatment
name
N
(kg ha1
)
P
(kg ha1
)
K
(kg ha1
)
Level of
detail
1 N0P0K0 0 0 0 High
2 N0P2K2 0 40 80 High
3 N1P2K2 40 40 80 Low
4 N2P2K2 80 40 80 High
5 N3P2K2 160 40 80 Low
6 N2P0K2 80 0 80 High
7 N2P1K2 80 20 80 Low
8 N2P3K2 80 80 80 Low
9 N2P2K0 80 40 0 High
10 N2P2K1 80 40 40 Low
11 N2P2K3 80 40 160 Low
12 N3P3K3 160 80 160 High
Non – Destructive methodology
• It provides a means of development of cassava under
different biophysical conditions.
• No needs big plots and allows to follow up the development
of the same plants.
• To generate, validate and improve the robustness of
simulation cassava models.
Level of detail Variables to measure
High All (fallen tags, branching, length,
diameter, etc)
Low Fallen tags and leaf area

5. Objectives
• To measure the growth and development of the cassava
crop under a range of conditions so as to further develop
and evaluate the simulation model. The development of
the model will include parameters for nutrient use which
are not included in any existing cassava simulation model.
• To assess the response of four cassava varieties to the
application of various combinations of N, P and K in order
to find the best and most economic fertilizer rate to obtain
and maintain high cassava yields.

6. Results
Yen Bai province

7. Troubles with data collection
59
7585

8. Leaf Area Index (LAI)
• Dimensionless variable.
• Soil area occupied by leaf area.
• LAI is an input for photosynthesis,
transpiration and VPD into the model.

9. Leaf Area Index (LAI)
Treatment
ID
Treatment
name
1 N0P0K0
2 N0P2K2
3 N1P2K2
4 N2P2K2
5 N3P2K2
6 N2P0K2
7 N2P1K2
8 N2P3K2
9 N2P2K0
10 N2P2K1
11 N2P2K3
12 N3P3K3

10. Plant Length (cm)
trt means M
5 295.516 a
12 294.86 a
11 290.6937 a
8 270.6236 ab
6 261.2262 b
10 247.844 bc
4 245.4255 bc
2 225.9893 cd
3 214.3992 de
7 210.6189 de
9 189.621 ef
1 173.7781 f
Df Sum Sq Mean Sq F Value Pr(>F)
Treatment 11 233013 21183 16.8793< 2.2e-16 ***
Block 1 9389 9389 7.4812 0.007134**
Variety 1 37666 37666 30.0132 2.24E-07***
Treatment:Variety 11 17662 1606 1.2794 0.24367
Residuals 126 158126 1255
trt means M
KM94 254.4487 a
KM2112 221.7872 b

11. Nodes (#)
Df Sum Sq Mean Sq F Value Pr(>F)
Treatment 11 15777 1434.3 4.6793 2.07E-06 ***
Block 1 1021 1020.9 3.3308 0.06938 .
Variety 1 24140 24140.2 78.7572 2.78E-16 ***
Treatment:Variety 11 4129 375.3 1.2245 0.272
Residuals 215 65901 306.5
trt means M
4 138.4 a
8 136.7 a
10 134.3 ab
5 132.95 ab
11 132.85 ab
2 131.8 abc
7 131.7 abc
12 127.75 abc
3 124.1 bcd
6 121.7 cde
9 116.2 de
1 110.8 e
trt means M
KM2112 138.3 a
KM94 118.2417 b

12. Leaf Area (cm2)
ID name
1 N0P0K0
2 N0P2K2
4 N2P2K2
6 N2P0K2
9 N2P2K0
12 N3P3K3

13. Yield (Kg/plant)
Df Sum Sq Mean Sq F value Pr(>F)
Treatment 11 11.374 1.03396 1.931 3.69E-02*
Block 1 0.704 0.70417 1.3151 0.25275
Variety 1 0.014 0.0135 0.0252 8.74E-01
Treatment:Variety 11 10.546 0.9587 1.7905 0.05701
Residuals 215 115.12 0.53544
trt means M
5 1.8925 a
10 1.8675 ab
7 1.8675 ab
3 1.81 ab
4 1.7975 ab
12 1.675 ab
9 1.64 ab
11 1.62 ab
8 1.485 abc
6 1.43 bc
2 1.4275 bc
1 1.1575 c

14. Stems weight (Kg/plant)
Df Sum Sq Mean Sq F Value Pr(>F)
Treatment 11 33.746 3.0678 10.1328 8.08E-15 ***
Block 1 2.109 2.1094 6.9672 0.00891 **
Variety 1 6.24 6.2404 20.6119 9.36E-06 ***
Treatment:Variety 11 4.281 0.3892 1.2856 0.23413
Residuals 215 65.093 0.3028
trt means M
5 1.7025 a
12 1.675 ab
8 1.55 abc
10 1.415 abc
7 1.355 bcd
11 1.33 cd
4 1.04 de
6 0.965 e
9 0.92 e
3 0.8375 e
2 0.75 ef
1 0.48 f
trt means M
KM2112 1.329583 a
KM94 1.007083 b
High N

15. Results
Dong Nai province

16. Troubles with data collection

17. Leaf Area (cm2)
(Alfredo et al. 2014)

18. Leaf Area (cm2)
numDF denDF F-value p-value
(Intercept) 1 869 9275.368 <.0001
Treatment 5 869 17.866 <.0001
Block 1 869 9.838 0.0018
Variety 1 869 9.412 0.0022
Treatment:Variety 5 869 4.575 0.0004
Value Std.Error DF t-value p-value
(Intercept) 180.679 6.385051 869 28.29719 0
Treatment2 1.35044 8.721111 869 0.154847 0.877
Treatment4 18.6622 8.570436 869 2.177509 0.0297
Treatment6 -11.4735 8.780338 869 -1.30673 0.1917
Treatment9 22.50452 8.651447 869 2.601244 0.0094
Treatment12 34.52381 8.658539 869 3.987256 0.0001
BlockII -10.9031 3.611548 869 -3.01894 0.0026
VarietySM937-26 -10.5996 8.919929 869 -1.1883 0.235
Treatment2:VarietySM937-26 -20.9536 12.58089 869 -1.66551 0.0962
Treatment4:VarietySM937-26 29.80754 12.28935 869 2.425477 0.0155
Treatment6:VarietySM937-26 7.64252 12.65043 869 0.604131 0.5459
Treatment9:VarietySM937-26 -4.93749 12.5696 869 -0.39281 0.6946
Treatment12:VarietySM937-26 -17.2598 12.61087 869 -1.36864 0.1715

19. Nodes (#) Leaves Leaf Scars
numDF denDF F-value p-value
(Intercept) 1 1168 6233.295 <.0001
Treatment 5 1168 4.37 0.0006
Block 1 1168 24.413 <.0001
Variety 1 1168 185.463 <.0001
Treatment:Variety 5 1168 2.793 0.0163
numDF denDF F-value p-value
(Intercept) 1 1098 2711.217 <.0001
Treatment 5 1098 30.209 <.0001
Block 1 1098 46.4476 <.0001
Variety 1 1098 306.4361 <.0001
Treatment:Variety 5 1098 2.7126 0.0191

20. Length (cm) Value Std.Error DF t-value p-value
(Intercept) 115.2059 2.052587 1170 56.12717 0
Treatment2 2.9927 2.68034 1170 1.11654 0.2644
Treatment4 10.7043 2.68034 1170 3.99364 0.0001
Treatment6 -0.15877 2.687039 1170 -0.05909 0.9529
Treatment9 16.5202 2.680246 1170 6.16369 0
Treatment12 17.7393 2.680246 1170 6.61853 0
BlockII -10.605 1.12178 1170 -9.45376 0
VarietySM937-26 -11.2547 2.680246 1170 -4.19913 0
Treatment2:VarietySM937-26 -7.4629 3.79044 1170 -1.96887 0.0492
Treatment4:VarietySM937-26 13.85552 3.795244 1170 3.65076 0.0003
Treatment6:VarietySM937-26 -1.0418 3.809984 1170 -0.27344 0.7846
Treatment9:VarietySM937-26 0.75603 3.805207 1170 0.19868 0.8425
Treatment12:VarietySM937-26 4.5777 3.815402 1170 1.19979 0.2305

21. Yield (kg/plant)
Df Sum Sq Mean Sq F value Pr(>F)
Treatment 11 10.886 0.99 5.4348 1.27E-07 ***
Block 1 1.944 1.944 10.6763 0.001263 **
Variety 1 32.561 32.561 178.8202 < 2.2e-16 ***
Treatment:Variety 11 2.509 0.228 1.2527 0.253982
Residuals 215 39.148 0.182
trt means M
8 1.8925 a
7 1.7175 ab
10 1.675 ab
11 1.54 bc
5 1.52 bc
3 1.49 bcd
12 1.4675 bcd
4 1.45 bcde
9 1.2625 cde
2 1.2475 cde
1 1.205 de
6 1.1675 e
Var means M
SM 1.837917a
KM 1.10125b
High P

22. Stems (kg/plant)
Df Sum Sq Mean Sq F value Pr(>F)
Treatment 11 8.906 0.80965 2.674 0.003085 **
Block 1 0.585 0.58509 1.9324 0.165934
Variety 1 0.667 0.66676 2.2021 0.139286
Treatment:Variety 11 4.463 0.40569 1.3399 0.204002
Residuals 215 65.098 0.30278
trt means M
12 1.31 a
11 1.0975 ab
8 1.075 abc
7 1.0425 abcd
5 0.97 abcd
10 0.915 bcde
4 0.9075 bcde
3 0.85 bcde
9 0.76 bcde
6 0.73 cde
2 0.7 de
1 0.595 e

23. Conclusions
• The data collection needs to be conducted carefully in order to avoid error sources into the experiment.
• Water deficit events affect the leaf expansion.
• For Yen Bai (North), overdose of fertilizers does not improve the yield (Roots weight) however, it increases canopy
biomass (vicious consumption). Thus, varieties present differences between them (genetic conditions)
• For Dong Nai (South), treatments with high P showed significant differences on yield whereas overdose of 3
fertilizers increases the canopy biomass (vicious consumption). Thus, varieties present differences between them
(genetic conditions)