Mycotoxin management in maize (Zea mays (L.)) damaged by Lepidopteran pests

• Main Author: Mays, Dennis Tyler
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2015
• Subjects: Agronomy; Plant Pathology
• ISBN: 1339426838; 9781339426839

Mycotoxins are secondary fungal metabolites that pose health risk to both animals and humans. Feeding damage caused Lepidopteran pests is believed to facilitate fungal infection increasing the risk of high fungal infection. The use of atoxigenic Aspergillus flavus strains is believed to be effective at reducing the contamination of aflatoxin and fumonisin. This study was conducted to evaluate the application timing based on growth stages of AF-36 and Afla-Guard. Treatments included an untreated control, insect control, AF-36 and Afla-Guard applied at the V8 and VT growth stage and Afla-Guard applied at the V8 and VT growth stage with insect control, arranged in a randomized complete block design replicated four times. The concentration of fumonisin was not significantly affected by the biocontrol products, but was significantly reduced by the insecticide applications (P= 0.029 and P<0.0001 in 2013 and 2014, respectively). The concentration of fumonisin in both years was significantly correlated with ear damage caused by Helicoverpa zea and Spodoptera frugiperda. Aflatoxin concentration in both years was not statistically affected by the biopesticide or insecticides (P=0.285 and P= 0.709 in 2013 and 2014, respectively). The concentration of aflatoxin in 2013 was positively relationship to the area of ear damage, while in 2014 no positive relationship was observed between the aflatoxin concentration and ear damage. Based on these results the insecticide control and Afla-Guard applied at the VT growth stage with insecticide applications at the whorl and tassel stages are the best options for reducing mycotoxin contamination in corn.