Environmental Entomology (2019) 48, 1401-1411

Luke S. Pruter, Michael J. Brewer, Mark A. Weaver, Seth C. Murray, Thomas S. Isakeit and Julio S. Bernal (2019)
Association of insect-derived ear injury with yield and aflatoxin of maize hybrids varying in Bt transgenes
Environmental Entomology 48 (6), 1401-1411
Abstract: Environmental factors have been associated with the production of aflatoxin in maize, Zea mays L., and it is inconclusive whether transgenic, Bacillus thuringiensis (Bt), maize has an impact on aflatoxin accumulation. Maize hybrids differing in transgenes were planted in two locations from 2014 to 2017. Yield, aflatoxin, and ear injury caused by corn earworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), were measured across three groups of hybrids differing in transgenes including near-isogenic hybrids, and water-stressed conditions. The hybrid groups consisted of non-Bt hybrids with no Bt transgenes, a second group with one or more Cry-Bt transgenes, and the third group with vegetative insecticidal Bt protein and Cry-Bt transgenes (Cry/Vip-Bt). Across the six data sets derived from 11 experiments, the Cry-Bt and Cry/Vip-Bt hybrids had less ear injury and aflatoxin on average than non-Bt hybrids. The effects of ear injury on yield and aflatoxin were more prominent and consistent in Corpus Christi, TX, where hybrids experienced more water-limited conditions than in College Station, TX. The trend of increased aflatoxin among hybrids with increased ear injury was further resolved when looking at Cry-Bt and Cry/Vip-Bt isogenic hybrids in Corpus Christi. The results supported that the maize hybrids with the inclusion of Cry-Bt and Cry/Vip-Bt transgenes warrant further investigation in an integrated approach to insect and aflatoxin management in sub-tropical rain-fed maize production regions. Research outcomes may be improved by focusing on areas prone to water-stress and by using hybrids with similar genetic backgrounds.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Michael J. Brewer, Mark A. Weaver, Julio S. Bernal

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa zea	Maize/corn (Zea mays)	U.S.A. (mid S)
	Spodoptera frugiperda	Maize/corn (Zea mays)	U.S.A. (mid S)
Bacillus thuringiensis genes in crops (entomopathogen)	Helicoverpa zea		U.S.A. (mid S)
Bacillus thuringiensis genes in crops (entomopathogen)	Spodoptera frugiperda		U.S.A. (mid S)