Fruit Pathology
People:
Dr. Janna Beckerman
Professor of Plant Pathology
Purdue
University
Botany and Plant Pathology, Lilly Hall
915 West State Street
West Lafayette, IN 47907-2054
Office: LILY 1-321
Phone: (765) 494-4628
FAX: (765) 494-0363
E-mail:
jbeckerm@purdue.edu
Program Description:
The goal of our research is to develop
environmentally sound disease management strategies that are economically
feasible for Indiana growers producing apples. To do so, we are developing two
web-based programs: 1) a program to assist growers in developing effective
fungicide rotations and 2) a forecasting tool for the major diseases that infect
apples. Our research effort is directly tied to our extension work, and focuses
on the identification and management of fungicide resistance. To that end, we
are currently surveying Indiana orchards to evaluate the incidence of fungicide
resistance in Venturia inaequalis, the fungus that causes apple scab,
and Glomerella cingulata, the causal agent of bitter rot. An effective fungicide
rotation, coupled with good forecasting tools reduces chemical inputs, and
minimizes the likelihood of fungicide resistance developing.
Apple scab is one of the most serious
diseases of apple and ornamental flowering crabapple, and affects both leaves
and fruit. In commercial apple 
production,
foliar infection by the apple scab pathogen results in defoliation that leads to
a loss of apple quality, and impacts winter-hardiness. Fruit infections result
in blemished and deformed fruit that cannot be sold. In commercial apple
production, this disease is primarily managed through the use of fungicides.
However, fungicide resistance is an emerging problem. We are currently surveying
the Venturia inaequalis population for the presence of fungicide resistance.
Recent restrictions 
in
fungicide registrations have resulted in the development of management issues
for diseases that were previously minor problems.
Bitter rot is a common orchard disease, but has been increasing in incidence and
severity across the Midwest due to changes in pesticide labeling. We are
currently collecting isolates from Indiana orchards to determine if fungicide
resistance, or changes in fungicide use has resulted in the increase of this
problem.
Current research involves the examination of surfactants combined with captan and mancozeb to reduce the rate and extend the interval between fungicide applications to control apple scab and other apple diseases, how to improve the management of overwintering inoculum, and fungicide trials to inform the recommendations in the Midwest Fruit Pest Management Guide.