CERTIFIED
PASS.
PEST CONTROL ADVISER · C A L I F O R N I A D E PA R T M E N T O F P E S T I C I D E R E G U L AT I O N
PCA Certification
Practice Question Bank
Cotton Harvest Aids, Defoliation & Desiccation
EXAM FOCUS:
Cotton Defoliation Physiology & Chemistry
— Harvest Aid Application Strategies
Edition 1 · July 2026
EXAM FOCUSED DETAILED CORE CONCEPTS BUILD CONFIDENCE
RATIONALES
Aligned with PCA Physiology, chemistry & Master your PCA certification
certification standards Clear explanations for every application exam
answer
P r e pa r e · P r a c t i c e · Pa s s
Excellence in Pest Control Adviser Certification
,PCA CERTIFICATION · COTTON HARVEST AIDS QUESTIONS 1–25
Section 1: Defoliation Fundamentals & Physiology
1 Defoliation in cotton production is best defined as:
A Leaf loss associated with application of a chemical that injures the leaf or
through natural senescence
B Accelerated drying of all plant tissue including stems and bolls
C The process of opening mature cotton bolls mechanically
D Removal of cotton lint from the seed after harvest
CORRECT ANSWER: A
CLINICAL RATIONALE: Defoliation refers specifically to leaf loss — either
chemically induced through harvest aids or naturally through maturation and
senescence as temperatures cool after boll development. It is distinct from
desiccation (tissue drying), mechanical boll opening, or ginning.
2 Desiccation is defined as:
A Accelerated drying of plant tissue
B Formation of an abscission layer at the petiole base
C Natural leaf drop due to cold temperatures
D Stimulation of boll opening through hormonal activity
CORRECT ANSWER: A
CLINICAL RATIONALE: Desiccation is rapid tissue dehydration — unlike
defoliation which involves abscission layer formation, desiccants quickly dry
leaves and other plant tissues. This process is faster under low humidity
conditions.
,3 Harvest aid chemicals facilitate machine harvest by:
A Influencing boll opening, reducing foliage, speeding tissue desiccation,
and controlling regrowth
B Only opening bolls without affecting leaves
C Killing the entire cotton plant including roots
D Increasing leaf production for better photosynthesis at harvest
CORRECT ANSWER: A
CLINICAL RATIONALE: Harvest aids serve multiple functions — promoting boll
opening, removing foliage that would contaminate lint, accelerating tissue
drying, and preventing regrowth that interferes with mechanical harvesting.
4 Which of the following is NOT a reason for using harvest aids in cotton?
A Increasing the amount of green leaf material in harvested cotton for
moisture retention
B Preparing cotton for harvest in a more predictable and timely manner
C Reducing leaf trash and other impurities at harvest and in the gin
D Improving the uniformity of boll opening required for mechanical
harvesting
CORRECT ANSWER: A
CLINICAL RATIONALE: Harvest aids REDUCE green leaf material — high-
moisture green leaves lower fiber grade and increase module moisture. The goal
is leaf removal, not retention, to improve fiber quality and harvest efficiency.
, 5 Manipulating harvest timing allows growers to:
A Work around their schedule, harvest before unfavorable weather, and
prevent perennial growth
B Eliminate the need for any mechanical harvesting equipment
C Harvest cotton only during rainy conditions
D Plant cotton at any time of year regardless of season
CORRECT ANSWER: A
CLINICAL RATIONALE: Harvest aids give growers scheduling flexibility, protect
against weather-related quality losses, and in California's climate, cotton would
likely become perennial without chemical defoliation to terminate the growing
season.
6 Harvest aids sustain cotton quality by preventing:
A Leaves from sticking to lint, staining, and high module moisture content
B Boll opening and fiber maturation
C The cotton plant from completing its life cycle
D Sunlight from reaching the cotton bolls
CORRECT ANSWER: A
CLINICAL RATIONALE: Quality preservation depends on clean leaf removal —
green leaves stain lint, stick to fibers, and introduce moisture that degrades
cotton in storage modules. Effective defoliation prevents these quality-damaging
conditions.
PASS.
PEST CONTROL ADVISER · C A L I F O R N I A D E PA R T M E N T O F P E S T I C I D E R E G U L AT I O N
PCA Certification
Practice Question Bank
Cotton Harvest Aids, Defoliation & Desiccation
EXAM FOCUS:
Cotton Defoliation Physiology & Chemistry
— Harvest Aid Application Strategies
Edition 1 · July 2026
EXAM FOCUSED DETAILED CORE CONCEPTS BUILD CONFIDENCE
RATIONALES
Aligned with PCA Physiology, chemistry & Master your PCA certification
certification standards Clear explanations for every application exam
answer
P r e pa r e · P r a c t i c e · Pa s s
Excellence in Pest Control Adviser Certification
,PCA CERTIFICATION · COTTON HARVEST AIDS QUESTIONS 1–25
Section 1: Defoliation Fundamentals & Physiology
1 Defoliation in cotton production is best defined as:
A Leaf loss associated with application of a chemical that injures the leaf or
through natural senescence
B Accelerated drying of all plant tissue including stems and bolls
C The process of opening mature cotton bolls mechanically
D Removal of cotton lint from the seed after harvest
CORRECT ANSWER: A
CLINICAL RATIONALE: Defoliation refers specifically to leaf loss — either
chemically induced through harvest aids or naturally through maturation and
senescence as temperatures cool after boll development. It is distinct from
desiccation (tissue drying), mechanical boll opening, or ginning.
2 Desiccation is defined as:
A Accelerated drying of plant tissue
B Formation of an abscission layer at the petiole base
C Natural leaf drop due to cold temperatures
D Stimulation of boll opening through hormonal activity
CORRECT ANSWER: A
CLINICAL RATIONALE: Desiccation is rapid tissue dehydration — unlike
defoliation which involves abscission layer formation, desiccants quickly dry
leaves and other plant tissues. This process is faster under low humidity
conditions.
,3 Harvest aid chemicals facilitate machine harvest by:
A Influencing boll opening, reducing foliage, speeding tissue desiccation,
and controlling regrowth
B Only opening bolls without affecting leaves
C Killing the entire cotton plant including roots
D Increasing leaf production for better photosynthesis at harvest
CORRECT ANSWER: A
CLINICAL RATIONALE: Harvest aids serve multiple functions — promoting boll
opening, removing foliage that would contaminate lint, accelerating tissue
drying, and preventing regrowth that interferes with mechanical harvesting.
4 Which of the following is NOT a reason for using harvest aids in cotton?
A Increasing the amount of green leaf material in harvested cotton for
moisture retention
B Preparing cotton for harvest in a more predictable and timely manner
C Reducing leaf trash and other impurities at harvest and in the gin
D Improving the uniformity of boll opening required for mechanical
harvesting
CORRECT ANSWER: A
CLINICAL RATIONALE: Harvest aids REDUCE green leaf material — high-
moisture green leaves lower fiber grade and increase module moisture. The goal
is leaf removal, not retention, to improve fiber quality and harvest efficiency.
, 5 Manipulating harvest timing allows growers to:
A Work around their schedule, harvest before unfavorable weather, and
prevent perennial growth
B Eliminate the need for any mechanical harvesting equipment
C Harvest cotton only during rainy conditions
D Plant cotton at any time of year regardless of season
CORRECT ANSWER: A
CLINICAL RATIONALE: Harvest aids give growers scheduling flexibility, protect
against weather-related quality losses, and in California's climate, cotton would
likely become perennial without chemical defoliation to terminate the growing
season.
6 Harvest aids sustain cotton quality by preventing:
A Leaves from sticking to lint, staining, and high module moisture content
B Boll opening and fiber maturation
C The cotton plant from completing its life cycle
D Sunlight from reaching the cotton bolls
CORRECT ANSWER: A
CLINICAL RATIONALE: Quality preservation depends on clean leaf removal —
green leaves stain lint, stick to fibers, and introduce moisture that degrades
cotton in storage modules. Effective defoliation prevents these quality-damaging
conditions.
