Presentation at CIAT about the non-destructive monitoring method for cassava, being applied in experiments in Latin America (Colombia), Africa (Nigeria, Tanzania) and Asia (Vietnam).

1. Non-destructive
methodology
for data collection
in cassava
Background and updates
Jonatan S. Soto
E-mail: j.s.soto@cigar.org

2. OUTLINE
• INTRODUCTION
• OBJECTIVES
• THE PLANT STRUCTURE AND PREVIOUS CONCEPTS
• MATERIALS
• MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
• AN EXAMPLE (FILLING THE FIELD BOOK)
• QUIPU STRATEGY
• CURRENT APPLICATIONS

3. INTRODUCTION
Low cost
and
logistically
easy to
collect data
Useful
methodology
for measuring
Cassava
development
Not blocks or
high number of
plots are
required
Following
the growth
for a same
plant
Generate,
validate and
improve
robustness of
Cassava
simulation
models
Understanding
the crop
development
(varietal
differences)
James Cock.
Patricia Moreno.
James Cock
Patricia Moreno
Myles Fisher
Julian Ramirez
Mayra Toro
Jonatan Soto

4. OBJECTIVES
• To collect all possible information about growth and
development of cassava crop during the crop cycle.
• To use the collected information for improvement and
calibration of cassava simulation models.
• To improve this methodology when necessary.

5. THE PLANT STRUCTURE AND PREVIOUS CONCEPTS
• Apex: It is a single path from the stick until one terminal
point (highlighted on yellow).
• Section: It is a portion of the apex which grew up from a
branching point to the upper one (red on figure).
• Sub-section: When in a section the number of leaves +
number of leaf scars >=20, it is equally divided in 3
parts. Each one of these parts is called a sub-section.
(blue on figure)

6. MATERIALS

7. MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
• Record of germination
50%
• First sampling
50%
Biweekly samplings

8. MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
Tags: Define a path on the apex!
New tag in the youngest
leaf with a petiole
separated of the stem
Do not use large tags in order to avoid
its contact with soil and earlier damage

9. MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
Data for the whole plant
Identify fallen tags (if so)
Count total number of active
stems in all apexes
Look for dead branches (varietal
feature)
Canopy cover (Canopeo® app)
Leaf Area Index (PocketLAI® app)

10. MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
Data for the whole followed apex
Leaf area (Easy Leaf Area® app)
Youngest, completely expanded and healthy leaf.
Total number of branches at lasts
Branching point.

11. MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
Data for each section on the apex
Section ID New Leaves: Count the number of
leaves after last tag
Lignified stem or not?
Total number of leaves Total number of leaf scars+ >=20
Divide the section in 3 equal
parts

12. MEASUREMENTS AND THE EXCEL FORM (FIELD BOOK)
These data corresponds to basic
plant identification.
How many
stems are at
the last
branching
point? i.e: 3
Total number
of stems in
the whole
plant (active
ones)
Fill this space
according to the
stem which is being
evaluated on the
followed apex.
Complete these fields.
Filling one row per
section.
Look for the
youngest,
completely
expanded
and healthy
leaf and
measure it.
If “total number of leaves”
+ “Total Number leaf scars”
>=20, divide the section in
3 equal sub-sections and
measure length and
diameter for each one.
Otherwise, if “total number
of leaves” + “Total Number
leaf scars” <20, don’t
consider sub-sections.
Measure the whole section
and fill the length and
diameter in “sub-section 1”.

13. Follow only one apex!
AN EXAMPLE (FILLING THE FIELD BOOK)
10/2/16 1 KM60 IV 1 8/25/16 318+
Other
Terminal
stems
0 75.15 1.8 0 0 L
0
35
0,1 0 L
0
28
0,1,1 0 NL
12
15
183.5
0,1,1,1 6 NL
10
0
Stick
42.33 30 38.56 29 39.33 37
35.28 35 32.26 31 31.35 30
30.85 28 28.67 25 29.49 55
15.35 12 NA NA NA NA
Other
stems

14. QUIPU STRATEGY
A cassava plant at harvest carries much information of its development in its stem.
We have developed a methodology based on minimal sample preparation in the field with the history
recorded in digital photographs for semi‐automated analysis at a later date.
To develop a simple rapid methodology to
recover the development history of cassava
plants at the time of harvest.

15. QUIPU STRATEGY
 Number of leaves.
 Number of leaf scars
 Stem diameter
 Stem length
Volume?
Weigth estimation?
Automated process?

16. CURRENT APPLICATIONS
Vietnam fertilization experiments
2 varieties
2 replicates per verietie
5 plants per replicate
6 treatments with high detail
6 treatments with low detail*
*Just fallen tags and leaf area are measured. Quipu strategy will be implemented at harvest
120 plants for each
level of detail

17. CURRENT APPLICATIONS
CIAT HQ experiment for varieties evaluation
 To evaluate the growth and development of three
cassava varieties (MCOL22; CM523-7; MPER183)
under normal environmental conditions and
management.
 To evaluate the water dynamics in these trials.
 Calibrate and evaluate the model for these varieties.
Leaf area measurement with ImageJ
WHY?