Submitted to: Multicrop Aflatoxin and Fumonisin Elimination and Fungal Genomics Workshop-The Peanut Foundation
Publication Type: Proceedings
Publication Acceptance Date: 9/15/2006
Publication Date: 10/16/2006
Citation: Krakowsky, M.D., Ni, X., Davis, R.F. 2006. Correlations between biotic stresses and aflatoxin contamination in maize. In: Proceedings of the 6th Annual Fungal Genomics, the 7th Annual Multi-crop Fumonisin, and the 19th Annual Multi-crop Aflatoxin Elimination Workshops, October 16-18, 2006, Fort Worth, Texas. p. 95.
Interpretive Summary: not required
Technical Abstract: Aflatoxin, a toxin produced by the fungus Aspergillus flavus, is the most potent carcinogen found in nature. Aflatoxin contamination of maize is a chronic problem in the southern US, where high temperatures, water stress, and insect damage produce conditions conducive to infection of maize by A. flavus. The purpose of this research was to determine the relationship between two biotic stresses, leaf feeding by the fall armyworm (FAW), Spodoptera frugiperda, and root feeding by the root-knot nematode (RKN), Meloidogyne incognita, and contamination of grain with aflatoxin. In the first experiment, four hybrids (three commercial and one aflatoxin resistant) were grown in a split-plot design with whole plots representing FAW artificially-infested or non-infested conditions and split-plots representing a hybrid. FAW damage was evaluated at seven and fourteen days after infestation. In the second experiment, three commercial hybrids were grown in a randomized complete-block design in a field with high population densities of RKN. A fumigant nematicide was used to create plots with minimal nematode damage to compare to non-fumigated plots with a high level of nematode damage. Early (pre-plant), mid, and late (at harvest) season nematode population levels were estimated based on soil samples. Both experiments have been conducted for two years in Tifton, GA. Correlations between plant damage, plant stress, and yield and aflatoxin contamination can be used to evaluate the significance of particular biotic stresses on aflatoxin contamination of maize and determine the focus of genetic improvement and crop management programs.