36th International Carrot Conference Abstract

Toward an adaptive management strategy for the control of aster yellows in Wisconsin carrot

Kenneth E. Frost¹, Amanda Gevens² and Russell L. Groves³.

¹Research Associate, Department of Plant Pathology, 574 Russell Laboratories, University of Wisconsin, Madison, WI 53706 kfrost@wisc.edu (608) 262 – 9914; ²Assistant Professor, Department of Plant Pathology, 689 Russell Laboratories, University of Wisconsin, Madison, WI 53706 gevens@wisc.edu (608) 890 – 3072; ³Associate Professor and Entomology Extension Specialist, Department of Entomology, 537 Russell Laboratories, University of Wisconsin, Madison, WI 53706 groves@entomology.wisc.edu (608) 262 – 3229.

Insect management programs to control aster yellows (AY) in processing and fresh market carrot crops in Wisconsin rely on frequent foliar applications of synthetic pyrethroid insecticides to control the aster leafhopper, the vector of the aster yellows phytoplasma (AYp). Although successful for managing AY in a cost-effective manner, this approach presents considerable risk to worker safety and the environment because synthetic pyrethroids are broad-spectrum insecticides with documented toxicity to aquatic organisms and mammals. This research documents the strengths and weaknesses of a proposed refinement to the current IPM program for control of AY that uses reduced-risk (RR) insecticides. Specifically, aster leafhopper abundance, AY abundance, and crop yield and quality were evaluated for the current and proposed AY management programs. Historical pest scouting data was then used to examine the potential cost structures associated with the two IPM programs. Aster leafhopper abundance and AY symptoms were significantly lower in the proposed RR IPM program when compared to the currently used foliar insecticide program. Yields among the proposed programs were not significantly different. Based on historical data and current (2012) insecticide prices and associated application costs, the proposed RR program will cost more than the currently used foliar program in 2 of 11 years if a conservative threshold is used to inform the foliar insecticide applications in the current IPM program. The RR systemic insecticide program for ALH management was technologically and operationally feasible and may be economically feasible in high ALH years. The ability to choose the most cost-effective program in any given year will minimize plant protection costs in the long term, but relies on accurate predictions of the annual AY risk to inform grower management decisions.

Last updated Thursday, 25-Jul-2013 11:52:26 CDT