Location: Southern Insect Management Research
Project Number: 6066-22000-090-017-A
Project Type: Cooperative Agreement
Start Date: Sep 20, 2025
End Date: Sep 19, 2027
Objective:
The agreement focuses on sweetpotato research, a vital crop for small farmers in Mississippi's Delta region. As sweetpotato production expands annually, pest management challenges intensify. This research addresses two critical needs: identifying high-yielding cultivars and developing effective pest control strategies.
A cornerstone of our CRIS project (6066-22000-090-00D) is the annual evaluation of 10 sweetpotato cultivars and research on pest management at the Alcorn Farm in Mound Bayou. This work progresses through our cooperative agreement with Alcorn State University and a Plant Evaluation Material Transfer Research Agreement with North Carolina State University. The completion of the CRIS project milestones depends directly on our ability to conduct these evaluations.
1. To assess the adaptability of newly released sweetpotato cultivars from the National Sweetpotato Collaborators Group for optimal performance in small-scale farming operations across the Mississippi Delta
2. To characterize the influence of soil microbiome composition on sweetpotato root system health and development
3. To evaluate the comparative efficacy of conventional insecticides and biological pest control agents against wireworm (Elateridae) larvae in sweetpotato cultivation
Approach:
Sweetpotato cultivars will be sourced from Louisiana State University and North Carolina State University breeding programs. Field trials will be established at the Alcorn State University Research, Extension, and Demonstration Center in Mound Bayou, Mississippi.
The experimental design will evaluate multiple commercial formulations, including soil microbial inoculants for root development and plant growth regulators for canopy management. Treatment applications will be administered using a calibrated backpack sprayer (5-gallon capacity) at a concentration of 810 mg L-1 (equivalent to 140 g active ingredient ha-1). Control plots will receive water applications only. Treatments will be implemented at two intervals: initially at 14 days post-transplant and subsequently at 42 days post-transplant.
Comprehensive monitoring protocols will include:
•Continuous assessment of root development and vegetative growth throughout the growing season
•Biweekly surveillance of soil-dwelling and foliar insect pest populations using adhesive traps and sweep net sampling techniques.
•Root harvest at physiological maturity
•Post-harvest classification of sweetpotato roots according to USDA grade standards (Jumbo, U.S. No. 1, and Canner)
•Quantitative analysis of insect damage incidence and yield parameters
Wireworm (Conoderus vespertinus) larvae will be collected through collaborative efforts with Tennessee State University from various agricultural sites across Mississippi and Tennessee. Collection methods will employ wheat seed bait traps and systematic soil core sampling. Specimens will be maintained in soil-filled containers at ambient temperature (20-25°C), sustained on potato substrate until bioassay implementation.
Toxicological Assessment Protocol:
The comparative efficacy of conventional and biological pesticides will be evaluated through dual methodologies:
1.Contact toxicity via treated sweetpotato substrate exposure in controlled Petri dish environments
2.Direct topical application using a calibrated Potter Spray Tower, following established protocols (Van Herk et al., 2008)
Experimental Design:
•Test units: 10 late-instar larvae per replicate
•Replication: 4 independent replicates per concentration
•Total sample size: 40 larvae per insecticide concentration
•Control group: Equivalent sample size with standardized control solution
Mortality Assessment Schedule:
•Observation intervals: 12, 24, and 48 hours post-treatment
•Final evaluation: 7 days post-treatment
Data Analysis: Dose-response relationships will be quantified through the determination of both LC50 and LC90 values for each tested compound.
Agricultural Production Outcomes:
We will reduce pesticide use and costs for small farms through pest-resistant sweetpotatoes, optimize crop yields with improved soil microbiome solutions, update insecticide effectiveness data against wireworms, and validate new biological pest control methods.
Stakeholder Engagement:
We are building stronger networks between research institutions and local farming communities while creating hands-on research opportunities to develop future agricultural leaders through undergraduate and graduate programs.