1. Field Performance of A VipCotTM Line Against Heliothines in Louisiana
P. L. Bommireddy, J. Temple, K. Emfinger, P. Price
K. Fontenot, and B. R. Leonard

3. Evolution of Commercialized Bt Cotton
1996
Bollgard
Single gene
cry1Ac
(endotoxin)
2003
Bollgard II
Stacked genes
cry1Ac + cry2Ab
(endotoxins)
2008
VipCot
Novel Protein
Vip3A + cry1Ab
(exo/endotoxins)
2005
Widestrike
Stacked genes
cry1Ac + cry1f
(endotoxins) +

4. Vip = Vegetative insecticidal proteinTM
VipCot
Bacterium (Bt)
Vegetative stage
Reproductive stage
Cry
Vip
Vip = Vegetative insecticidal protein
VipCotTM = Vip3A + Cry1Ab

5. Objective
To determine level of fruiting form injury and survivorship of heliothine larvae on VipCot and non-transgenic cotton

6. Heliothis virescens (F.)
Primary Pests
(Heliothine complex)
Tobacco Budworm
Heliothis virescens (F.)
Bollworm
Helicoverpa zea (Boddie)
Larva

7. Study Site
Macon Ridge Research
Station - Winnsboro, LA
Years:

8. 1. Non-Bt (Coker 312) 2. Vip 3A 3. Vip 3A + Cry1Ab (VipCot)
Field Trial – Native Infestation
1. Non-Bt (Coker 312)
2. Vip 3A
3. Vip 3A + Cry1Ab (VipCot)

10. Design, Collection & Analysis
Completely randomized design
Injured fruiting forms (%), surviving larvae, seasonal durability
ANOVA (PROC MIXED)
Repeated measures ANOVA (PROC MIXED)

11. Vip 3A and VipCotTM Efficacy 2005-2007 Summary
Injury (%)
Infested forms (%)
Coker 312
14.1a
4.6a
Vip3A
4.1b
1.0b
VipCot
0.9c
0.1c
P > F
<
Means within a column followed by same letter are not statistically different
Sample n :

12. Seasonal Durability 2005-2007 Summary
No. / 25 fruiting forms
Days after planting

13. Non-Bt Bt

14. Cotton lines 1. Non-Bt (Coker 312) 2. Vip 3A
Field Trial – Artificial Infestation
Cotton lines
1. Non-Bt (Coker 312)
2. Vip 3A
3. Vip 3A + Cry1Ab (VipCot)
Two species
1. H. zea
2. H. virescens

16. Design, Collection & Analysis
RBD - Date of infestation as blocks
Sample size (n) = 75
Injured fruiting forms, surviving larvae
Repeated measures ANOVA (PROC MIXED)

17. Injured Fruiting Forms Days after infestation
H. zea
H. virescens
No. injured / 25 plants
Days after infestation

18. Days after infestation
Surviving Larvae
H. zea
H. virescens
No. per 25 larvae
Days after infestation

19. Distribution of Fruiting Form Injury
H. zea
H. virescens a a
No. /individual larva b b a a a a a a a a b c a c c b b b b b b b
Fruiting forms

20. Conclusions Low injury levels on Bt cotton lines
Combination of two proteins (Vip3A + Cry1Ab) gives better control
Season long efficacy

21. Acknowledgments
Ralph Sheppard, Sara Lowe, Sierra Jones, Beth Padgett, Betsy Lowe, Abbey Lockett, and other personnel at the Macon Ridge Research Station.
Louisiana
Cotton
Producers