Department of Botany and Plant Pathology

Kenneth B. Johnson Professor, Ph.D., 1986, University of Minnesota, St. Paul johnsonk@science.oregonstate.edu   Office/Lab: Cordley 3046/3047 Phone: 541-737-5249/5248

Research Area

Plant disease epidemiology with emphasis on disease ecology and integrated management strategies.

Description of Research

My research is concerned with understanding how variability in environment and in host and pathogen populations affects the development of plant disease. Our research results contribute to the development of  integrated disease control strategies. Recent projects have been concerned with biological control of fire blight of pear and apple, epidemiology of blackberry rust, and rapid detection of bacterial pathogens on seeds and flowers.

Research Group Members

Faculty Research Assistants/Associates

Teresa Sawyer
Todd Temple

Graduate Students
Drew Hubbard

Teaching

BOT 350 INTRODUCTION TO PLANT PATHOLOGY

BOT 552 PLANT DISEASE MANAGEMENT

BOT 550 PLANT PATHOLOGY

Publications

T. N., Temple, and Johnson, K. B. 2009. Rapid and early detection of Erwinia amylovora in pear and apple orchards using loop-mediated isothermal amplification (LAMP). (Abstr.) Phytopathology 99:S

Johnson, K. B., and Mahaffee, W. F. 2010. Factors influencing epidemiology and management of blackberry rust in cultivated Rubus laciniatus . Plant Dis. 94:

Johnson, K. B., Sawyer, T. L., Stockwell, V. O. and Temple , T. N. 2009. Implications of pathogenesis by Erwinia amylovora on stigmas of rosaceous flowers to biological control of fire blight. Phytopathology 99:128-138.

Temple , T. N., Stockwell, V. O., Pusey, P. L., and Johnson, K. B. 2007. Evaluation of likelihood of co-occurrence of Erwinia amylovora with mature fruit of winter pear. Phytopathology 97:1263-1273.

Johnson, K.B., Sawyer, T. L., and T. N. Temple. 2006. Rates of epiphytic growth of Erwinia amylovora on flowers common in the landscape. Plant Dis. 90:1331-1336.

Temple, T.N., Stockwell, V., Loper, J.E. and Johnson, K.B. 2004. Bioavailability of iron to Pseudomonas fluorescens A506 on flowers of pear and apple. Phytopathology 94: 1286-1294.

Johnson, K. B., Stockwell, V. O. and Sawyer, T. L. 2004. Adaptation of fire blight forecasting to optimize the use of biological controls. Plant Disease 88:41-48.

Stockwell, V.O., Johnson, K.B, Sugar, D., and Loper, J.E. 2002. Antibiosis contributes to biological control of fire blight by Pantoea agglomerans strain Eh 252 in the field. Phytopathology 92: 1202-1209.

Pinkerton, J.N, Johnson, K.B., Aylor, D.E., and Stone, J.K. 2001. Spatial and temporal increase of eastern filbert blight in European hazelnut orchards in the Pacific Northwest. Phytopathology 91:1214-1223.

Johnson, K.B., Stockwell, V.O., and Sugar, D. 2000. Assessment of environmental factors influencing growth and spread of Pantoea agglomerans on and among blossoms of apple and pear. Phytopathology 90:1285-1294.

Johnson, K.B. 1999. Dose-response relationships for biocontrol of plant disease and their use to define pathogen refuge size. Pages 385 -392 in: Theoretical Approaches to Biological Control, Hawkins, B.A. (ed.). Chapman & Hall, New York.