Raymond G. Grogan, professor of plant pathology at the University of
California, Davis was born in Emma, GA, July 22, 1920, and educated at the
North Georgia College of Dahlonega and the University of Georgia at
Athens, where he earned the B.S. and M.Sc. degrees. After a three-year
stint in the Navy, he went to the University of Wisconsin to obtain the
Ph.D. degree under J.C. Walker in 1948.
He began his career at the University of California, Davis, in 1948, was
promoted to professor by 1960, and served as department chairman from 1969
to 1974. Professor Grogan taught courses on advanced plant pathology and
diseases of vegetable and field crops and guided 23 Ph.D. degree and
several M.S. students.
In 1987, Dr. Grogan was awarded the Award of Distinction by the American
Phytopathological Society. The Award of Distinction formally recognizes
exceptional productivity in research, inspiring leadership, and effective
application of plant pathology for the benefit of humanity. This rarely
bestowed honor has been presented only ten times in the history of the
Society and Dr. Grogan was the seventh recipient.
Dr. Grogan served the profession as president of the APS Pacific Division,
chaired the Committee on Editorial Policy for Phytopathology, and served
as APS representative to AAAS and other committees. He served on editorial
boards of Phytopathology, Plant Disease, Virology, and the Annual Review
of Phytopathology. Dr. Grogan was awarded a National Science Foundation
Postdoctoral Fellowship in 1958 and the Campbell Award for vegetable
research in 1962, was named fellow of APS in 1969, and was included in
Who's Who in America in 1974.
His innovative, diverse, and creative research included foliar and
soilborne diseases of vegetable crops caused by viruses, bacteria, fungi,
and abiotic factors. Under J.C. Walker's tutelage, Grogan demonstrated
that a necrotic disease of bean was caused by a hypersensitivity in
resistant cultivars to bean common mosaic virus; later, he showed this
seedborne virus to transmitted by bean pollen.
At Davis, Grogan and associates demonstrated that June yellows in lettuce
was caused primarily by the seedborne lettuce mosaic virus and could be
controlled by using virus-free seed. He established that the soilborne
chytrid, Olpidium brassicae, transmitted the big-vein agent in lettuce,
which was the first report of a fungus as a vector of a disease agent.
Later, in Australia, he and a colleague described lettuce necrotic
yellows, a virus disease that served as a model for basic research on
bullet-shaped viruses. Grogan found that tomato mosaic virus could be
transmitted mechanically from tomato seed to seedling.
Dr. Grogan discovered that Pseudomonas tomato inhabits and is transmitted
by tomato seed, and that P. phaseolicola, cause of halo blight of bean, is
a seed contaminant in which sanitation is needed to produce bacterium-free
seed. Using nucleic acid hybridization he identified four of six
homologous groups of pseudomonads with distinct genotypic
characterizations. More recently he and co-workers reported that corky
root rot of lettuce is caused by a soilborne gram-positive bacterium, and
that this disease can be controlled by cultural practices that improve
soil water drainage and aeration.
Grogan's research led to detection of a new mutant strain of lettuce
powdery mildew that is endemic on wild lettuce in California and that
caused the mildew epidemics during the 1950s. He incorporated resistance
to lettuce downy mildew in Lactuca serriola from Russia into L. sativa and
this resistance in the lettuce cultivar Calmar has been effective for
nearly 30 years. In other work, Grogan established: 1) the importance of
seed transmission in celery by Septoria apii and that crop rotation and
use of disease-free seed are effective controls, 2) that stem canker of
tomato is caused by Alternaria alternata, leading to the identifiable
stable resistance probably from a single dominant gene, and the
identification (with co-workers) of a host-specific toxin useful in
screening tomato cultivars for resistance, and 3) that lettuce drop is
caused by Sclerotinia minor and S. sclerotiorum with extensive research
into the biology, epidemiology, and control of these two species.
Difficult problems in research challenge Dr. Grogan; this was demonstrated
when he determined in the 1950s that the cause of root rot, rapid
collapse, and death of lettuce plants in the field was caused by damage
from ammoniated nitrate fertilizer. He concluded that high temperatures
and calcium deficiency at or near crop maturity contributed to tip burn of
lettuce and symptom development.
Few have contributed to science and plant pathology as Ray Grogan has.
After years of experience, he developed a philosophy that inspired two
articles, "The Science and Art of Plant-Disease Diagnosis" and
"The role of Genetics in Etiological Pathology and Maintenance of
Plant Health." Throughout his career, Dr. Grogan strived for
excellence in himself while instilling it in his students. To him,
research is challenging and fun, and he often compared research to solving
a crossword puzzle in which the problem is not solved until all of the
squares are filled. His devotion to that philosophy accounted for the many
contributions to plant pathology in particular and to agriculture,
science, and education in general.
Dr. Grogan is retired and lives in Santa Cruz, California.