Pruter, Luke Steven (2019-11). Integration of Disease and Insect Risk Assessment and Management in Maize. Doctoral Dissertation. Thesis uri icon

abstract

  • Ear injury principally caused by Helicoverpa zea (Boddie) and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is potentially linked to Aspergillus flavus (Link) in maize. Preharvest infection of maize kernels by A. flavus, occurring in sub-tropical maize producing regions of the world puts maize at risk of aflatoxin contamination. Global temperatures are on the rise, potentially further increasing risk. The risks associated with A. flavus occurrence leading to aflatoxin contamination of kernels are affected by a suite of potentially interacting factors that include these ear-feeding insects, fungal inoculum potential, weather (rainfall, temperature, and humidity), and the ability of maize to resist or tolerate pests, pathogens, and environmental stress. Modern maize production can benefit from the integration of pest and pathogen management (IPM) principles guided in part by an understanding of the risk factors. Research focused on the integration of the most efficient pest and pathogen management strategy combinations and the interactions of these factors, such as the association of insect ear-feeding and A. flavus occurrence, may help resolve the combined influences and identify best-combined management approaches to reduce aflatoxin risk. Selection of appropriate hybrid for the region, with tactics of excluding (biological control of A. flavus using non-aflatoxigenic strains), avoiding (cultural practices like early planting to avoid pests), and reducing (plant resistance to ear-feeding insects using Bt transgenes).

publication date

  • November 2019