Project Overview
Commodities
- Fruits: peaches
Practices
- Pest Management: biological control, integrated pest management
Proposal abstract:
Peach is an important specialty crop in the Southeastern United States. In 2021, South Carolina and Georgia produced over 120,000 tons of fruit valued at over $170 million. Recently the sustainability and high-quality production of this nutritional crop has been challenged due to the restrictions on the use of the broad-spectrum insecticide chlorpyrifos set by the U.S. Environmental Protection Agency. While there are alternative insecticide options for many foliar pests of peaches, there are currently no effective chemical solutions for borer pests such as the lesser peachtree borer. Fungal entomopathogens have historically been utilized for biological control, however commercial adaptation is limited by fungal sensitivity to environmental factors and the cryptic nature of target pests. Researchers have recently begun to overcome these limitations by establishing fungal entomopathogens as endophytes (fungi living inside of plant tissue) in crop plants including the woody perennials pecan, coffee, and cacao. This study aims to develop the use of the entomopathogenic fungi Beauveria bassiana as an endophyte in peach as an alternative, safe and sustainable integrated pest management strategy for the key insect pest, the lesser peachtree borer.
Project objectives from proposal:
The outputs from this project will directly benefit Southeastern peach growers in that the research is expected to result in identifying a novel sustainable, safe, and effective tool for management of LPTB.
Objective 1: Establish B. bassiana as an endophyte in peach (P. persica)
Inoculation of host plants with EPF can vary based on specific plant propagation requirements. Differing inoculation methods result in varying successes of endophyte establishment in distinct plant tissues. In most studies seed, root, and soil inoculation methods are overall less successful compared to foliar and stem injection methods. However, foliar application results in better colonization of leaf tissues while soil drenching and seed soaking favor root colonization (Bamisile et al., 2018). The purpose of this objective is to confirm commercially available B. bassiana strain GHA can become endophytic in a Guardian® rootstock of peach and determine the best method of inoculation.
Objective 2: Determine the effect of the introduction of B. bassiana on the native fungal endophyte community in peach
Previous studies have reported a decrease in recovery of EPF from inoculated plant tissues over time, indicating the EPF is only present and protecting plant tissues for a limited time. This could in part be due to the host plant’s naturally occurring endophytes which may have negative effects on the establishment of introduced EPF through competition or exposure to metabolites. Furthermore, natural endophyte diversity and richness varies with host plant species, age, and environment in which the plant is grown (Vega, 2018). To better understand the dynamics of the fungal endophyte network and the challenges faced by the introduced fungal entomopathogen over time it is necessary to identify and compare naturally occurring endophytes with and without inoculation of an EPF in a controlled environment. The purpose of this objective is to determine if there is an effect of introducing B. bassiana on the native fungal endophyte community in peach. Results from this study will help determine possible factors that may affect the successful establishment of this EPF in plants providing knowledge to aid in the continued development of endophytic EPF as a broad-spectrum sustainable biocontrol management strategy for arthropod pests in general.
Objective 3: Determine virulence of peach tissue containing endophytic B. bassiana against LPTB larvae
The purpose of this objective is to confirm peach tissues containing endophytic B. bassiana are pathogenic to larvae of the lesser peachtree borer.