Page 40 - Grapevine July-Aug 2020

Around The Vineyard

about the introduction and spread of SARS-COV-2
world-wide will provide a lesson to people to think
twice before breaking the law by introducing plant
material without import permits or respecting
quarantines.

Plant quarantine programs have been developed
worldwide to reduce the risk of introducing plant
pests and/or pathogens that do not occur in a
country or region. My expertise is plant patholo-
gy and throughout my career I have specialized in
the study of bacteria, fungi, and viruses that affect
the vineyard and fruit orchards. In spite of the
current existence of plant quarantine programs, all
grapevine pathogens with rare exceptions occur
in all grape growing areas worldwide. The reason
for this is that in most cases, quarantine programs
were implemented after the introduction of the
infected plant material. In addition, modern tech-
niques for the detection of these pathogens were
developed after the plant material was introduced.
In other words, the majority of grapevine pests and
pathogens were moved unknowingly.

The advancement of science and the use of
sophisticated detection methods for grapevine
pathogens has helped keep certain viruses out-
side of Australia. For example, Grapevine fanleaf
(GFLV) and Grapevine red blotch viruses (GRBV)
have not been reported in Australia as of yet. But
even now with the use of advanced methodol-
ogies, pathogens continue to be discovered. As
science progresses with the development of more
refined technology (e.g., next generation sequenc-
ing also known as high throughput sequencing),
it is expected that new (or unknown and estab-
lished) pathogens will be discovered. In practice,
most grapevine pathogens have originated at the
centers of origin of the Vitis (a plant genus that
includes both table, wine, and rootstock grapevine
varieties) species and moved to many grapevine
growing regions in the word when plant material
was introduced.

In the United States, the USDA APHIS PPQ regu-
lates the introduction of plant material for planting
from foreign countries. However, the USDA does
not have a centralized government plant quar-
antine system. Instead, APHIS issues permits to

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