Location: Southern Horticultural Research
Project Number: 6062-21430-004-036-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 8, 2023
End Date: Jul 8, 2024
The overall objective is to enhance the sustainability and efficiency of the regional nursery industry in the U.S. by removing entomological, pathological, and cultural barriers to efficient, sustainable production of woody ornamental nursery crops. Specifically, we will investigate the biology, ecology, and behavioural traits of ornamental pests, such as flathead borers, ambrosia beetles, and associates to improve management recommendations. Additionally, this project investigates lower risk products and techniques for managing ornamental pests as well as evaluating insecticide efficacy in alternative substrates for container grown nursery crops, and chemical and non-chemical weed management practices for nursery crop production and propagation. Also, under evaluation for disease efficacy trials are conventional chemical and biorational products for controlling soil-borne pathogens using different application methods, intervals, and reduced-rate applications in woody ornamentals. The project aims to further develop improved root disease management strategies based on cultural approaches for suppression of Rhizoctonia, Phytophthora spp., and other soil-borne pathogens. Additionally, techniques will be developed to use precision agriculture technologies (AI augmented image analysis) to facilitate early detection of disease and insect infestations in nursery production to permit early mitigation strategies.
Research will be performed that improves management of trunk-attacking wood borers in commercial nurseries by developing treatments that lower producer costs, improve treatment efficacy, are safer for farm labor, and enhance sustainability while still integrating into existing production systems. Research will focus on 1) development of new insecticide treatments and rates for flatheaded borers and ambrosia beetles, 2) cultural techniques to reduce attacks, 3) manipulation of borer behavior with traps and other attractants to prevent attacks, and 4) development of better phenological and degree-day predictors of borer activity to better time treatments and scouting activity. Another indirect goal of the above methods will be expansion and development of treatments that minimize impacts on other beneficial insects like pollinators and biological control agents. Alternative container substrate components (compost, wood chips, etc.) will be combined with pine bark at varying proportions and treated with insecticides (granular and drenches) to evaluate efficacy for controlling Japanese beetle larval development and imported fire ant. New practices (drench volume, application rates, application methods) will also be developed to maximize insecticide efficacy in these substrates. Fungicides and biorational products will be evaluated for ability to control soilborne diseases (Rhizoctonia solani, Sclerotinia spp. and Phytophthora spp.) under greenhouse conditions. The experiment will be established at the Tennessee State University, Otis Floyd Nursery Research Center in McMinnville, Tennessee, as a randomized complete block design with four replications. Cultural approaches include crop rotation/cover crop (Arugula and/or clover), good quality compost amendment, solarization will be evaluated for soil-borne diseases (Rhizoctonia solani, Sclerotinia spp. and Phytophthora spp.) under field conditions. The experiment will be conducted as a randomized complete block design with four replications. Plots will be artificially inoculated with each pathogen then each cultural approach will be applied to raised beds. Plots will be irrigated as needed. Hydrangea and maple cuttings will be planted in spring and disease occurrence and incidence will be evaluated throughout the trial. Image analysis technologies will be developed by using machine learning algorithms to permit the detection of common nursery disease and insect pests on a large-scale basis. Detection technologies will be compared to standard ground-based human scouting for efficiency in detecting pest outbreaks before they reach economically damaging thresholds.