Maize for Asian tropics: Chasing the moving target. P.H. Zaidi

1. P. H. Zaidi,
CIMMYT-Asia Maize Program, Hyderabad, India
E-mail: phzaidi@cgiar.org
Maize for Asian tropics:
Chasing the moving target

2. Asian Maize RD&D Partners and Donors
For strong commitments & engagement with CIMMYT-Asia!
Partners:
ICAR-IIMR, Ludhiana, Punjab, India
NMRI, Ha Noi, Vietnam
NSFCRC, Tak Fa, Thailand
BARI, Gazipur, Bangladesh
MMRI, Sahiwal, Pakistan
NMRP, Rampur, Chitwan, Nepal
IAS, BHU, Varanasi, U.P., India
AAU, Anand, Gujarat, India
UAS, Raichur, Karnataka, India
BAU, Sabor, India
Corteva Agrisciences, Hyderabad, India
Kaveri Seeds Pvt. Ltd., Hyderabad, India
Ajeet Seeds, Aurangabad, India
BRAC Center, Dhaka, Bangladesh
BIOSEED, Hyderabad, India
LalTeer Seeds, Bangladesh
Krishibid, Bangaldesh
SEAN, Nepal
TATA Trusts, India
Donors:
ICAR/DARE, Govt. of India
USAID F-t-F Initiative of the US Govt.
BMZ/GIZ, Germany
Syngenta Foundation for Sustainable Agriculture
CGIAR-CRP Maize Agrifood system
RKVY, Govt. of Odisha
Govt. of A.P. & Karnataka, India
Thank you!

3. Maize trends in Asia:
Production, Demand, Consumption & Net trade
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
Overall
2010-11
2011-12
2012-13
2013-14
2014-15
2015-16
Overall
2010-11
2011-12
2012-13
2013-14
2014-15
2015-16
Overall
2010-11
2011-12
2012-13
2013-14
2014-15
2015-16
Overall
2010-11
2011-12
2012-13
2013-14
2014-15
2015-16
Overall
2010-11
2011-12
2012-13
2013-14
2014-15
2015-16
Production
World Asia East Asia Southeast Asia South Asia
(Source: FAOSTAT, 2018)
85%
70%
36%
0
50
100
150
200
250
300
E Asia SE Asia S Asia
1997 2020 % change
Demand(MMT)
70%
58%
82%
-1%
-8%
-43%-60
-40
-20
0
20
40
60
80
100
S Asia SE Asia E Asia
Food Feed Other Net Trade
Percentage
Percentchanges

4. ~20%
Irrigated
~80%
Rainfed
7%
Spring
High-input environment
but Heat stress-prone
13%
Winter
High-input/high yielding environment
11%
Optimal
moisture
Good environment w/o any
major stresses
16%
Drought <500mm rainfall, drought (+/-heat)
15%
Excess
moisture
>1500mm rainfall, excess-
moisture/water-logging
38%
Drought/Ex
cess
moisture
Erratic distribution pattern of monsoon,
prone to drought (+/-heat) and waterlogging
within same crop cycle.
Maize mega-environment in Asian tropics
a challenging environment!

5. (Source: Erickson et al., 2011)
 Drought: Frequency increased as
8 severe drought years in last 14
years
 ~70% land drought prone; 22%
flood prone and 18% to cyclones
 Heat: frequent episodes of heat
waves; e.g. in 2016 soaring Tmax
past 45°C in Thailand, 42°C in
Cambodia, and 50°C in parts of
South Asia.
 Frost: common in northern
regions, e.g. severe yield loses in
winter maize in South Asia during
2017-18
Climate change effects in Asian tropics
A challenging environment further challenged!
(Increased frequency of inter-annual variability/weather extremes!)

6. Downy mildew score (1–5)
S.No. CML No. 2002 2010
1 CML-433 1.5 1.0
2 CML-465 1.5 1.5
3 CML-466 1.0 1.5
4 CML-472 1.0 1.5
5 CML-471 1.0 2.5
6 CML-427 1.5 3.5
7 CML-430 1.5 3.5
8 CML-467 1.5 3.5
9 CML-429 1.5 4.0
10 CML-431 1.5 4.0
11 CML-470 2.0 4.0
12 CML-428 1.5 4.5
13 CML-468 2.0 4.5
14 CML-473 2.0 4.5
15 CML-425 1.5 5.0
16 CML-426 2.0 5.0
17 CML-432 1.5 5.0
18 CML-469 2.5 5.0
19 CML-474 1.0 5.0
(Rashid et al., 2013)
Climate change effects in Asian tropics
More virulent strains of diseases/pests
FAW

7. Observed Annual Rainfall in Asian tropics in the Last 100 Years
Climate varies at different temporal scales
Source: Walter E. Baethgen, 2016
How important is each scale?
Which one to follow for crop production?

8. Inter-annual variation in rainfall during Monsoon months
(Aug & Sep) during past 10 years (2007-17)
High deficit
Flooding
Deficient
Excessive
Normal

9. *
*
* *
30
35
40
45
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
Tmax(≥35-400C≤)duringspringseasonindifferentyears
Planting Vegetative growth Flowering, Poll.,
Fert. & Early GF
Late GF
2010 (09-23 Week)
2011 (10-22 Week)
2012 (09-24 Week)
2013 (12-22 Week)
2014 (12-26 Week)
2015 (12-23 Week)
2016 (10-22 Week)
2017 (12-23 Week)
2018 (10-22 Week)
** *** *
Prolonged Tmax (~ 1week) ≥35.0 – 37.50C = Heat stress; >37.50C = Severe heat stress
* *
** * *
**** *
* *** *
*
* *
** ** * **
* *** * * * *
400C
350C
Heat stress

10. Stress-resilient technology, that gives
high yields under OPTIMAL & resilience under:
 Drought/Heat/Waterlogging/anaerobiosis
 Agronomic package(s) for enhancing system
resilience
 Resistance to major biotic stresses
How to deal with this variability/uncertainty?
0
25
50
75
100
June
July
Aug
Sep
Monsoon months
Weeklyrainfall(mm)
Drought Water-logging Drought
Planting Vegetative stage Reproductive stage

11. Protect (attainable) yields
(Source: updated from Edmeades et al., 2007)
(80.2%)
(39.26%)
(40.96%)
 Some major break-through!
 More efficient/ideal plant type,
 Innovative crop agronomy to
support new plant type
Grainyield(tha-1)
 Stress resilient cultivars
 Agronomic package(s)
enhancing resilience
 Scale & gender neutral
tools/technologies
 Reduce other losses
(post-harvest)
WL-tolerant
DT-tolerant

12. 0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
TN
PB
TN
WB
KN
TP
BR
RS
MP
TN
HR
UK
TN
UK
MH
RS
MP
KN
ANP
CG
TN
OR
UP
KN
UP
MP
ASM
WB
ANP
AP
PB
UK
MP
HP
UP
UP
TN
UK
AP
CG
MP
CG
CG
ANP
ANP
CG
BR
CG
MH
HP
UP
MP
NG
UP
RS
RS
ANP
TN
UP
TN
UP
UP
CG
TP
MP
MP
UP
MP
UP
JK
UP
UP
JK
UP
OUT of TOTAL = 514 districts
<1.0 t/ha = 19
1.0 - <2.0 t/ha = 200
2.0 - <3.0 t/ha = 196
3.0 - <4.0 t/ha = 82
>4.0 – 6.5 = 17
Average 2.26 t ha-1
Min 0.31 t ha-1
Max 6.53 t ha-1
Kharif yields of 514 districts*
*District-wise mean yields for last three years (2013-14, 2014-15 & 2015-16)
The ≥5.0t Challenge
Where to pay more
attention?
Protect (attainable) yields
(e.g. rainfed maize in India)

13. 0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Z822-2
Check-3
Z822-6
Check-5
Check-1
Z822-1
Z822-3
Check-6
Check-2
Z822-4
Z825-1
Z825-3
Z824-4
Check-4
Z825-2
Z824-1
Z824-3
Z824-2
Z822-7
Moderate locations
(Mean of 19 locations)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
Check-6
Z822-6
Check-4
Check-2
Z825-1
Check-1
Z822-3
Check-3
Z822-4
Check-5
Z825-3
Z825-2
Z822-7
Z822-2
Z824-1
Z824-3
Z822-1
Z824-4
Z824-2
High-yielding locations
(Mean of 11 locations)
Grainyield(t/ha)
Target downside risk reduction, with upside potential
0.0
1.0
2.0
3.0
4.0
5.0
6.0
Z822-6
Z825-3
Z824-4
Z822-3
Z824-2
Z825-2
Check-6
Z824-3
Z822-2
Z824-1
Z822-7
Z825-1
Z822-1
Check-2
Z822-4
Check-3
Check-5
Check-1
Check-4
Low-yielding locations
(mean of 27 sites)

14.  Causes yield-drag under optimal conditions ( !? )
 It’s a myth, no truth!
 Stress resilient germplasm will
be equally competent, depends
upon -
1. Constitution of base germplasm
(Stress donor + Elite lines)
2. Selection criteria (across stressed and
un-stressed environment)
Breeding stress-resilient maize…
 It is grain yield across
environment that gets maximum
weightage while selecting for
stress resilience
Average breeding progress (Banziger et al, 2006)
Percent yield increase of experimental hybrids (n=42) over checks
(n=41), evaluated over 60 locations
0%
5%
10%
15%
20%
25%
0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 >9
Average trial yield (t/ha)Yieldincreaseoverchecks
+
+* * ***
*** ***
***
***
***
Trial #: 18 41 38 48 31 27 21 22 20 7
Low yielding environments High yielding environments
ns
***
**
***
**
+
ns
ns
ns
-10
-5
0
5
10
15
20
25
30
35
1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10
Percentagegainoverchecks
Mean yield (t ha-1) of the trial
Yield gains with stress-resilient hybrids over
checks evaluated at 52 sites in S & SE Asia
Low Yield Env. High Yield Env.
(Das et al., 2018; TS6-90, 13th AMC)
Moderate Yield Env.
Stress-resilient maize = Normal maize
Equipped to cope-up with odds, whenever it comes!

15. using integration of novels tools and methods with
proven rules of abiotic stress breeding
• Field-based high precision phenotyping
• Base germplasm with key ingredients
• Genomic-based breeding - GWAS for
MTA, RC-GS etc.
• Double haploid (DH) technology
• Root traits phenotyping & integration
Breeding stress-resilient maize…

16. Constitution of base population:
foundation-stone for a stress resilient breeding program
Identify inbred lines (8-10)
Intermate to form F1’s (P1 P2,P1 P3….)
Intermate F1’s
(F1 F1)
Self to derive families
S2:3 families test crossed to
opposite heterotic group testers
TC evaluated under managed DT and WL trials
Intermate top 5-10% S2:3 based on progeny test
cross to constitute C1
Recurrent selection for 2-3 cycles (RC-GS);
derive lines (DH) from advanced cycle
Genotype S2:3 families
Lines Reactions
CAL146
DT+Elite*
VL108871 DT*
VL108851 DT+Elite
ZL11884 DT+Elite
VL1010090 Elite*
CAL14101 WLT
ZL11447 WLT
VL1018820 WLT+Elite
CIL12102 DT&WLT*
ZL11959 Elite
Lines Reactions
CAL157 DT*
VL062623 DT+Elite*
VL109086 DT+Elite
CAL1733 DT&WLT
VL109138 Elite
ZL182115 WLT+Elite*
ZL182116 WLT
CAL1436 WLT
ZL182117 WLT+Elite
CIL12180 Elite
(MPS-A) (MPS-B)
* Stalk rot score ≤5.0; All lines with good resistance to
common foliar diseases (TLB & rust)

17. Desirable root phenotype for stress-resilience
Rooting volume (cm3 plant-1 )
Rooting length-density
(cm cm-3 )
Stress period water-use (litres)
Transpiration efficiency
(g litre-1)
AAA project (SFSA)

18. RFLP
RAPD
SSR
SNP
GBS-SNPs and
Indels
Full genome re-
sequencing
Genomics
evolves
rapidly…!
Epigenome
Methylome
Proteome
Metabolome
RNAi
profiling
(Courtesy: Raman Babu, CIMMYT/Corteva )

19. Manual/
time consuming
Phenotyping
Replication-1
Replication-2
Subjective!

20. High-throughput Precision Phenotyping (HTPP)
Accurate Not Accurate
Precise
Not precise
Courtesy: Vincent Vadez, ICRISAT
2. Precision phenotyping : (Precision + Accuracy)
 In conducting the trials/experiments (location, crop
management, stress management)
 In observations/data capture
1. High-throughput:
Fast-tracking data capture using
digital imaging tools
(proximal/remote).

21. • But NOT precise, as
it’s a BAD trial!
• Several traits within an hour!
• High throughout , cheaper, accurate!

22. • And precise, as it’s a
well-managed, good trial!
All three aspects are important, but
the order of priority may be:
1. High precision in field trial
>2. Accuracy in data capture
>3. High throughput
• Several traits within an hour!
• High throughout , cheaper, accurate!

23. Drought Heat Waterlogging
Precise phenotyping for key abiotic stresses…

24. Focus on cost-effective, affordable tools,
deployable across-sites
High-throughput phenotyping
Digital data capture using proximal/remote sensing
(M. Zaman-Allah CIMMYT

25. Harmonized phenotyping protocols
A must for across-site trials

26. y = -0.0686x + 3.8792
R² = 0.0163
0.00
1.00
2.00
3.00
4.00
5.00
6.00
0.00 1.00 2.00 3.00 4.00 5.00
Grainyieldunderwaterlogging(t/ha)
Grain yield under drought (t/ha)
GY of selected fraction
under Optimal condition
(7.4 – 11.6 t/ha)
Waterlogging
Tolerant
Drought
Tolerant
CRMA project, (funded by GIZ, Germany)
Combined DT
and WL Tolerant
Selection across moisture regimes
(DT, WL and Optimal)

27. Grainyield`(t/ha)
Water stress resilient hybrids
0.00
2.00
4.00
6.00
8.00
10.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Optimal Drought Water-logging
Commercial checks
CRMA project, (funded by GIZ, Germany)
Stress Resilient Hybrids

28. Heat stress projection in South
Asia and advantage of HT hybrids
Kindie et al. 2017 (TAC, DOI 10.1007/s00704-016-1931-6)
Pre-monsoon Monsoon season
Increase in heat-stressed area (%)
HT-hybrids
Current hybrids
Impact of CC on maize yields by 2030
Heat Tolerant Maize for Asia (HTMA), Funded by USAID F-t-F

29. 0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
2008 2009 2010 2011 2012 2013 2014 2015 2016
Spring season maize
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
2008 2009 2010 2011 2012 2013 2014 2015 2016
Tmax Tmin
Rainy season maize
DT DT DT
Temperature(0C)
Temperature regime in South Asia during flowering/grain-filling stage of maize

30. Mild-stressSevere stress
Natural heat stress by managing planting
time & tracking GDD
HTMA – USAID project

31. All heats are not same!
Different types of heat stress:
► High VPD sites (Tmax: 35 - >400C; VPD: >5.0 kPa)
► Moderate VPD sites (Tmax: 35 - >400C; VPD: 3.0-5.0kPa)
► Low VPD sites (Tmax: 35 - 400C; VPD: <3.0 kPa)
(Vinayan et al., 2018; TS06-125, 13th AMC)
HTMA phenotyping network

32. Advanced stage HT hybrids under heat stressGrainyields(tha-1)
0.00
2.00
4.00
6.00
8.00
ZH16857
ZH16930
ZH1689
ZH16107
ZH16878
ZH1688
ZH16418
ZH16341
ZH16311
ZH16779
ZH16162
ZH16333
ZH16386
ZH16410
ZH16929
ZH16881
ZH16199
ZH16271
ZH16262
ZH1770
ZH16946
ZH16153
ZH16128
ZH16150
ZH16222
ZH16477
ZH1690
ZH15445
ZH16930
ZH16530
ZH16114
ZH16782
ZH16840
ZH16605
ZH16322
ZH16402
ZH16817
ZH15281
ZH16910
ZH16931
ZH16869
ZH16297
ZH1695
ZH16234
ZH16778
ZH16161
ZH16467
ZH161027
ZH16873
ZH16598
Check-1
Check-3
ZH15266
Moderate VPD sites (Tmax: 35 - >400C; VPD: 3.0-5.0 kPa)
# Locations: 9
14ENT
10ENT
4ENT
1ENT
17ENT
0.00
2.00
4.00
6.00
8.00
10.00
Low VPD sites (Tmax: 35 - >400C; VPD: <3.0 kPa)
# Location : 8
64 ENT61 ENT
0.0
2.0
4.0
6.0
8.0
ZH16851
ZH16881
ZH16856
ZH16879
ZH16875
ZH16930
ZH1776
ZH16322
ZH16135
ZH16532
ZH16822
ZH16399
ZH16873
ZH1623
ZH16122
ZH16477
ZH15281
ZH16878
ZH16902
Check-5
ZH16887
ZH1655
ZH1770
ZH16809
ZH16114
ZH16929
ZH1695
ZH1770
ZH161027
ZH16868
ZH16131
ZH1775
ZH16857
ZH16422
ZH16782
ZH16931
ZH16899
Check-1
Check-4
ZH16175
Check-3
ZH16843
ZH1652
Check-2
ZH16410
ZH16918
High VPD sites (Tmax: 35 - >400C; VPD>5.0 kPa)
# Locations: 8
107 ENT

33. Performance across VPD regimes, # Locations: 31
New generation of heat stress resilient hybrids
0.0
2.0
4.0
6.0
8.0
ZH15432
ZH137119
ZH15366
ZH138098
ZH142040
ZH138069
CAH155
ZH15370
ZH16981
VH112887
ZH138119
ZH15422
ZH1619
ZH15317
Check-4
VH131167
Check-2
ZH16878
ZH111755
ZH15390
ZH15331
ZH137087
VH142085
ZH15400
ZH141592
ZH15410
Check-1
Check-5
Check-3
ZH15416
ZH141592
High VPD Moderate VPD Low VPD
Grainyields(tha-1)
Low VPD sites = Tmax: 35 - 400C; VPD: <3.0 kPa
Mod. VPD sites = Tmax: 35 - >400C; VPD: 3.0-5.0kPa
High VPD sites = Tmax: 35 - >400C; VPD: >5.0 kPa

34. Sharing germplasm & products…
• International Maize Improvement Consortium (IMIC)-Asia
Deployment & scale-out of new hybrids, including CIMMYT x CIMMYT or CIMMYT
(donors) x partner lines
• Partnerships through bi-lateral projects, e.g.-CRMA, HTMA, IMTA
etc. Research, development, deployment & scale-out
• Partnerships with other developmental projects in region (e.g.NSAF, AIP etc.:
Deployment & scale-out

35. A multi-funnel approach
20-30 hybrids 20-30 hybrids 20-30 hybrids 20-30 hybrids 20-30 hybrids 20-30 hybrids
Focus on specific adaptability/niche markets, along with wider-adaptation
Hybrid 2,5,17, 20 Hybrid 1,5,8,10 Hybrid 3,5,11,24 Hybrid 14,15,18 Hybrid 7,15,21,27 Hybrid 2,13,24,29
After stage-3 testing….
Selection of high-yielding stress-resilient hybrids….

36. Farmers (women & men) participatory selection

37. Opt- Wet season optimal, HT-Heat, WL-managed water logging, DT-Managed Drought
One-size doesn't fit to all!
Combination of traits for various stress-prone ecologies
Grainyields(tha-1)
OPT+HT+WL+DT OPT+HT+DT Opt+WL+DT OPT+DTOPT+HT+WL At least two
OPT/HT/WL/DT
(Das et al., 2018, TS6-90, 13th AMC)

38. To conclude..
► Maize in Asian tropics is largely rain-fed
exposed to weather extremes; often face compound effects
of multiple stresses
► Asian tropics are highly vulnerable to climate change effects,
with high inter-annual variability, which adds further
challenges to an already challenging environment
► Native variation exist in tropical maize,
though at low frequency, that could be systematically
pyramided in stress-resilient varieties.
► The way forward : targeted improvement for
High-yielding stress-resilient (rather than high-yielding
risky) maize with plasticity to cope with climate variability
► Demand for maize in Asia and climate change effects –
surpassing most of the projections

39. Thanks for your Attention!