Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Gore, Jeff

Committee Member

Catchot, Angus

Committee Member

Cook, Don

Committee Member

Crow, Whitney

Date of Degree

4-28-2021

Original embargo terms

Worldwide

Document Type

Graduate Thesis - Open Access

Major

Entomology

Degree Name

Master of Science

College

College of Agriculture and Life Sciences

Department

Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology

Abstract

In field experiments, thresholds, spray timings, and bollworm oviposition were conducted to evaluate the current recommended action thresholds for bollworm (Lepidoptera: Noctuidae) in cotton. Based on studies conducted evaluating thresholds, insecticide applications varied across Bt technologies. Bollgard 3 required less sprays when compared to Bollgard II and non-Bt. A second experiment highlighted the importance of timely insecticide applications for managing bollworm populations in Bollgard II cotton based on insect damage. The highest yields were associated with insecticide applications made during the timeframe that cotton is the most susceptible to bollworm damage. The last experiment was conducted to determine if oviposition varied throughout the plant canopy. Oviposition occurred throughout the whole plant, however, the greatest relationship of egg lay was observed in the top three nodes of the plant. From this research, studies would suggest that the current recommended bollworm thresholds in Mississippi cotton production systems, at this time, do not need to be adjusted.

Sponsorship

Cotton Incorporated, USDA-ARS

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