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ARS Home » Southeast Area » Stoneville, Mississippi » Biological Control of Pests Research » Research » Research Project #432515

Research Project: Biocontrol of Aflatoxin and Other Mycotoxins in Maize Using Non-toxigenic Strains of Aspergillus flavus

Location: Biological Control of Pests Research

Project Number: 6066-42000-006-00-D
Project Type: In-House Appropriated

Start Date: Dec 31, 2016
End Date: Dec 30, 2021

Objective:
The overall objective of this project is the improved biological control of aflatoxin in corn through a more complete ecological understanding of the pathogen and the agroecosystem through applied investigation of biocontrol agent delivery systems. Over the next 5 years, our research will focus on the following objectives: Objective 1: Enhance shelf life, survival growth, germination, and host colonization of biocontrol agents for aflatoxin management through formulation improvements. Objective 2: Refine aerial, foliar and seed treatment application strategies of biocontrol agents for aflatoxin management. Objective 3: Develop and implement molecular markers for post-release tracking of foliar and seed treatment biocontrol applications. Objective 4: Determine population size, chemotype and mating type frequency in soil-borne Aspergillus (A.) flavus populations and subsequent infections in corn to improve predictions of aflatoxin risk and enhance biocontrol measures. Sub-Objective 4a.Correlation of aflatoxin contamination of corn with the population distribution of A. flavus in soil. Sub-Objective 4b. Correlating A. flavus mating type with corn infection. Objective 5: Apply novel formulation and application technology to other pathogen biocontrol systems.

Approach:
Biological control technology is an effective method for reducing aflatoxin contamination in corn; however, present formulation and application strategies are still rudimentary and fundamental gaps remain in our knowledge of the population structure of Aspergillus (A.) flavus. Improved application technology will be developed aimed at increasing adoption of biocontrol measures by increasing efficacy and convenience of the application systems. Although previous efforts using a water dispersible formulation did not meet industry standards, they provided avenues for further research using bioplastic as a vector for application of biocontrol agents. Corn starch-based bioplastics are naturally-derived, biodegradable, recyclable, inexpensive, and provide nutrition favoring fungal growth after application. Bioplastics are easily prepared by heating commercial bioplastic for 2-3 hours at 80-90°C and applying (i.e., aerial, foliar, and seed treatment) after cooling. Bioplastic vectors promise to provide effective, efficient delivery of biocontrol agents. We also plan to develop and implement molecular markers for post-release monitoring of biological control agents. The resulting data will enable optimizing delivery tools to meet industry standards. Knowledge of local A. flavus population size, chemotype and mating type frequency will also lead to a better understanding of aflatoxin risk and permit more sound decisions of when fields warrant application of commercial biocontrol products. Domestic and international industrial companies have already inquired and invested in the development of this technology for control of various agricultural pests beyond just A. flavus. Optimization of these techniques during the next five years will improve the efficiency and practicality of biocontrol agents used in agriculture.