Apoorva Arora

1. Quantifying stripe rust reaction in
wheat using remote sensing based
hand held NDVI sensor
Apoorva Arora
Directorate of Wheat Research, Karnal

2. Normalized
difference
vegeta2on
index
(NDVI)
Ø Func2on
of
incident
and
reflected
light
NDVI=
NIR
–
Red
,
NIR
+
Red
NIR
750-­‐1300
nm
Red
600-­‐700
nm
Ø Foliar
pigments
dominate
reflectance
measurements
0<
NDVI<
1

3. Stripe
Rust
and
NDVI
Ø Breakdown
of
foliar
pigments
Ø Foliar
physiological
ac2vity
decreases
Ø Less
reflactance
of
infrared
by
healthy
vegeta2on
and
vice
versa
Ø Decrease
in
value
of
NDVI
NASA
Earth
Observatory
(Illustra2on
by
Robert
Simmon)

4. Why
NDVI
Ø Most
sensors
provide
measurements
in
NIR
&
Red
por2on
of
spectrum
Ø Addi2ve
gene
governed
rust
resistance
geZng
more
a[en2on
than
ever
before
Ø Minor
varia2ons
can
be
captured
by
quan2ta2ve
varia2on

5. High
Throughput
Screening
Gap
Phenotyping
Genotyping
Phenotyping
in
field
condi1ons…??

6. Rust
Scoring
Methodology

8. Satellite
based
Remote
sensing:
Limita2ons
Ø Atmospheric
condi2ons
Ø Satellite
geometry
&
calibera2on
Ø Soil
backgrounds
Ø Crop
canopy
Ø Angle
of
solar
radia2on
incidence
Ø Small
plots
can’t
be
used
for
measurements

9. Objec2ve
.
Quantifying stripe rust reaction in
wheat using remote sensing based
hand held NDVI sensor

10. Research
Methodology

11. Study
Material
322
genotypes
Pedigree
analysis
Diversity
analysis
120
genotypes
Released
varie1es,
Local
land
races,Elite
wheat
genotypes
Represen1ng
each
group

12. Field
Experiment
LaZce
Design

13. Plan2ng
Method

14. Epiphyto2c
Condi2ons
Ø Epiphyto2c
condi2ons
created
by
plan2ng
suscep2ble
check
on
either
sides
of
plot
Ø Inoculated
with
Yr27
virulent
race
78S84
of
Puccinia
striiformis

15.
Equipment
Ø Recorded
data
using
handheld
ac2ve
op2cal
GreenSeeker
sensor
(Trimble
Industeries,
Inc.)
Ø NDVI
computed
from
reflectance
measurements
in
red
(~660nm)&
near
infrared
(around
780nm)por2on
of
spectrum
Ø Display
value
in
range
of
0.00
to
0.99

16. RESULTS

17. AUDPC
wise
distribu2on
of
genotypes
Ø AUDPC
computed
varied
from
0
to
2077
Ø Equal
number
of
genotypes
in
all
categories
except
in
AUDPC
range
of
1-­‐100

18. NDVI
Ø Recorded
when
crop
showed
symptoms
of
maximum
infec2on
Ø Value
of
NDVI
varied
from
0.46
to
0.69
Ø Mean
values
across
different
AUDPC
range:
0.58
to
0.69
Ø Value
reduced
with
increase
in
incidence
of
disease

19. NDVI
vs
AUDPC
Ø Regression
equa2on
for
NDVI
using
AUDPC
:
NDVI=0.663+-­‐6.165E-­‐5(AUDPC)t
Ø Significant
correla2on
depicted
by
r2
value
of
0.63
NDVI
AUDPC

20. Effect
of
Spot
Blotch
Ø Spectral
quality
of
reflected
light
from
leaves
manifested
in
leaf
color
Ø
NDVI
values
also
got
affected
by
the
presence
of
spot
blotch
Ø Quan2fied
value
of
NDVI
due
to
blotch
alone
was
added
(if
required)

21. Ø Mean
NDVI
values
amer
correc2on:
0.64
to
0.76
Ø Regression
equa2on
for
Corrected
NDVI
vs
AUDPC:
NDVI=0.738
+-­‐7.061E-­‐5(AUDPC)t
Ø Correla2on
(r2
)
value
improved
to
0.69
NDVI
AUDPC

22. Plant
physiological
factors
AUDPC
Ø Correla2on
coefficient
showed
significant
values
Ø Correla2on
value
improved
as
categories
shimed
from
predominantly
resistant
to
suscep2ble
types
AUDPC
Range
Coeff.
of
determina2on
(r2)
Correla2on
coefficient
0-­‐200
0.20
-­‐0.45
>200
0.72
-­‐0.85

23. Plant
Height
Plant
Height
(in
cm)
No.
of
genotypes
Coeff.
of
determina1on
(r2)
Correla1on
coefficient
65-­‐74
3
0.76
-­‐0.87
75-­‐84
15
0.62
-­‐0.79
85-­‐94
50
0.62
-­‐0.79
95-­‐104
35
0.73
-­‐0.85
105-­‐114
14
0.57
-­‐0.76
115-­‐124
2
1.00
-­‐1
Ø Value
of
correla2on
coefficient
increased
as
taller
types
were
more
suscep2ble
Ø Range
of
coefficient
:
0.76
to
1.00

24.
Ø Similar
value
of
correla2on
coefficient
obtained
Ø No
significant
difference
between
categories
was
no2ced
Waxiness
and
Early
Growth
Habit

25. Conclusion
Ø With
increasing
a[en2on
towards
quan2ta2ve
rust
resistance
studies,
innova2ve
tools
&
techniques
are
needed
Ø NDVI
sensor
technique
provides
mean
value
of
several
images
captured
from
the
plot
as
against
single
frame
observa2on
by
human
eye
Ø High
correla2on
value
indicates
suitability
of
the
instrument
as
an
useful
tool
for
accurate
rust
data
recording
Ø Accuracy
of
this
method
improves
when
catagoriza2on
of
genotypes
accrued
to
predominance
of
susep2bility

26. Inspiration behind
work…

27. Dr.
Indu
Sharma
Project
Director
Directorate
of
Wheat
Research
Karnal
Dr.
M.
S.
Saharan
Principal
Scien1st
Dr.
R.K.
Sharma
Principal
Scien1st
Dr.
K.
Venkatesh
Scien1st
Davender
Sharma
Sr.
Research
Fellow

28. Thank You