Effect of Varying Levels of Boll Feeding Bug Damage on Fiber Quality

Effect of Varying Levels of Boll Feeding Bug Damage on Fiber Quality

P. Roberts, A. Knowlton, and J Ruberson (UGA)J. Bacheler, D. Mott, D. Morrison, T. Pegram (NCSU)

J. Greene, D. Robinson, T. Walker, S. Turnipseed, M. Sullivan (Clemson)

R. Smith (Auburn), C. Bednarz (TTU)

Piercing and sucking mouthpart.

Feeds primarily on fruiting structures and meristematic tissues (seed and surrounding tissues in cotton bolls).

Injects digestive enzymes.

Extracts dissolved plant tissue and sap.

Physical destruction of seed (lint production reduced).

Introduces or allows entry (wounds) of pathogens and decay organisms.

Stink Bug Feeding

Prefer medium sized bollsSmall bolls shedLarge bolls remain on the plantSusceptible <25 days of age (yield)

Stink BugSusceptible

0

0.5

1

1.5

2

2.5

3

5 10 15 20 25 30 35 40 45Boll age, days

Len

gth

.cm

0102030405060708090

bol

l wei

ght,

mg

Elongation Deposition

Fiber Development StagesElongation / Secondary Wall Deposition

-0.05

0

0.05

0.1

0.15

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Node

2% 7% 16% 33%

L(w) [in] (Treated – Untreated) All Locations, hand-picked by position

AFIS – Cotton Incorporated

Picker Efficiency of damaged bolls?

Lint cleaners, other ginning processes?

Objective and Methods Quantify the impact of bug damage on fiber quality. 24 field trials established in GA, NC, SC, & AL (2005)

Untreated vs. Bug Treated Intermediate Treatments

Threshold Progressive Protection

Machine-Picked Cotton Simulate Commercial Ginning (UGA MicroGin) HVI, AFIS (Cotton Incorporated) Large data set with a range of bug damage.

Compared differences in quality values with most aggressive treatment in a given trial.

Grouped differences of treatment means from individual trials by yield loss (assumed yield loss due to bug damage).

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

<0 0-99 100-199 200-299 300-499 500+

Yield Loss (lbs lint/acre) vs Aggressively Sprayed

Dif

fere

nce

fro

m A

gg

ress

ive

+b (yellowness)

n=23 n=6n=14n=22 n=7

HVI and AFIS – Cotton IncorporatedN=24 locations, 103 treatments (79 comparisons)

mean=8.308

2005 SE Regional Stink Bug ProjectUGA MicroGin

n=7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

<0 0-99 100-199 200-299 300-499 500+


Dif

fere

nce

fro

m A

gg

ress

ive

Staple Length (32nds)

n=23 n=6n=14n=22 n=7


mean=35.93


n=7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

<0 0-99 100-199 200-299 300-499 500+


Dif

fere

nce

fro

m A

gg

ress

ive

Length Uniformity Index

n=23 n=6n=14n=22 n=7


mean=81.95


n=7

-0.035

-0.03

-0.025

-0.02

-0.015

-0.01

-0.005

0

0.005

<0 0-99 100-199 200-299 300-499 500+


Dif

fere

nce

fro

m A

gg

ress

ive

L(w) [in]

n=23 n=6n=14n=22 n=7


mean=0.985


n=7

-0.5

0

0.5

1

1.5

2

2.5

<0 0-99 100-199 200-299 300-499 500+


Dif

fere

nce

fro

m A

gg

ress

ive

L(w) CV [%]

n=23 n=6n=14n=22 n=7


mean=34.42


n=7

-0.5

0

0.5

1

1.5

2

2.5

<0 0-99 100-199 200-299 300-499 500+


Dif

fere

nce

fro

m A

gg

ress

ive

SFC (w) [%]

n=23 n=6n=14n=22 n=7


mean=9.030


n=7

UGA Micro-Gin (HVI) 2005Stink Bug Trials, GA, SC, and AL

2005 Untreated

20 Percent

ThresholdAggressively Sprayed

Lint/acre 760 a 1125 b 1232 b

Lint % 34.93 a 36.21 b 36.25 b

MIC 4.27 a 4.37 b 4.43 b

UHM (32nds) 35.62 a 36.01 b 36.03 b

UI 81.18 a 81.63 b 81.60 b

STR 30.08 a 29.97 a 30.06 a

Rd 75.37 a 76.81 b 77.23 b

+b 9.04 a 8.46 b 8.25 bHVI – Cotton IncorporatedN=11 locations (trial means analyzed as reps)

UGA Micro-Gin (AFIS) 2005Stink Bug Trials, GA, SC, and AL

2005 Untreated20 Percent Threshold

Aggressively Sprayed

Nep size (um) 703.4 a 692.6 b 691.5 b

Neps per Gm 308.9 a 255.2 b 244.0 b

L(w) [in] 0.9542 a 0.9734 b 0.9806 b

L(w) CV [%] 36.65 a 35.51 b 35.11 b

UQL (w) [in] 1.180 a 1.192 b 1.199 b

SFC (w) [%] 11.21 a 10.02 b 9.61 b

L (n) [in] 0.6894 a 0.7204 b 0.7304 b

L (n) CV [%] 62.09 a 59.40 b 58.57 b

SFC (n) [%] 36.41 a 33.53 b 32.57 b

L5% (n) [in] 1.321 a 1.337 b 1.343 b

AFIS – Cotton IncorporatedN=11 locations (trial means analyzed as reps)

UGA Micro-Gin (AFIS) 2005Stink Bug Trials, GA, SC, and AL

2005 Untreated20 Percent Threshold

Aggressively Sprayed

Total Cnt/g 413.0 a 322.2 b 293.7 b

Trash Size [um] 360.7 a 364.2 a 366.8 a

Dust Cnt/g 332.1 a 257.8 b 233.9 b

Trash Cnt/g 80.55 a 64.07 b 59.45 b

VFM [%] 1.702 a 1.325 b 1.212 b

SCN Size (um) 1065 a 1073 a 1084 a

SCN (Cnt/g) 23.86 a 17.50 b 16.79 b

Fine [mTex] 172.9 a 173.8 ab 175.6 b

IFC [%] 5.359 a 5.016 b 4.820 b

Mat Ratio 0.9148 a 0.9214 ab 0.9274 b

AFIS – Cotton IncorporatedN=11 locations (trial means analyzed as reps)

“Identifying Practical Knowledge and Solutions

for Managing The Sucking-Bug Complex In Cotton:

Research In The Southeast Region”

Southeast State Support Committees

Documents

Effect of Varying Levels of Boll Feeding Bug Damage on Fiber Quality