New bacterial products for control of pecan pests

Authors: Shapiro Ilan, David; Cottrell, Ted; Bock, Clive; MIZELL, RUSSELL - University Of Florida

Submitted to: Southeastern Pecan Growers Meeting Proceedings
Publication Type: Other
Publication Acceptance Date: 3/26/2017
Publication Date: 4/1/2017
Citation: Shapiro Ilan, D.I., Cottrell, T.E., Bock, C.H., Mizell, R.F. 2017. New bacterial products for control of pecan pests. Southeastern Pecan Growers Meeting Proceedings. http://sepga.com/Presentation/WEB2017pres/PresentationsShapiro-Ilan.pdf.

Interpretive Summary: Pecans are economically the most important native nut crop in the USA. Among the major concerns are the pecan weevil, pecan aphids, and diseases such as pecan scab. These pests are generally controlled with broad spectrum chemicals. The chemical pesticides can be harmful to the environment and garner secondary pest outbreaks and resistance. Our overall goal for this project is to develop alternative production practices for pecans that are sustainable and effective. The research reported herein focuses on pecan weevil and aphid control and also suppression of pecan scab. The focus of the research has been on the use of novel environmentally friendly insecticides based on bacterial products. We discovered that a bacteria-based product (Grandevo®, based on a bacteria called Chromobacterium subtsugae), significantly reduced pecan weevil damage in USDA and commercial pecan orchards. Additionally, the bacterial product reduced pecan aphid populations. This is especially important because some of the chemical insecticides used to control pecan weevil actually cause an increase in aphids due to destruction of natural enemies. All the products used are deemed safe to humans and the environment and can be used in organic farming settings. Also, we found that the bacteria-based product (Grandevo®) controlled pecan weevil at the same level as conventionally used chemical insecticides. Furthermore, we discovered new fungicidal activity in by-products derived from the bacteria called Xenorhabdus and Photorhabdus species. The by-products and one of their safe bioactive chemicals, trans-cinnamic acid, are active against pecan scab and other fungal diseases of pecans. The findings show great promise for developing environmentally sound pest management tactics in pecan and other crops.

Technical Abstract: Pecans are economically the most important native nut crop in the USA. Among the major concerns are the pecan weevil (Curculio caryae), pecan aphids, and diseases such as pecan scab, Venturia effusa. These pests are generally controlled with broad spectrum chemicals. The chemical pesticides can be harmful to the environment and garner secondary pest outbreaks and resistance. Our overall goal for this project is to develop alternative production practices for pecans that are sustainable and effective. The research reported herein focuses on pecan weevil and aphid control and also suppression of pecan scab. The focus of the research has been on the use of novel environmentally friendly insecticides based on bacterial products. We discovered that a bacteria-based product (Grandevo®, based on Chromobacterium subtsugae), significantly reduced pecan weevil damage in USDA and commercial pecan orchards. Additionally, the bacterial product reduced pecan aphid populations. This is especially important because some of the chemical insecticides used to control pecan weevil actually cause an increase in aphids due to destruction of natural enemies. All the products used are deemed safe to humans and the environment and can be used in organic farming settings. Also, we found that the bacteria-based product (Grandevo®) controlled pecan weevil at the same level as conventionally used chemical insecticides. Furthermore, we have discovered new fungicidal activity in metabolites derived from the bacteria Xenorhabdus and Photorhabdus species. The metabolites and one of their bioactive chemicals, trans-cinnamic acid, are active against pecan scab and other fungal diseases of pecans. The findings show great promise for developing environmentally sound pest management tactics in pecan and other crops.