Page 64 - Grapevine July-Aug 2020

Around The Vineyard

capable of dispersing live microorganisms when nomenon that occurs in vineyards due to water pres-
foraging,” said Anne Madden, Ph.D., first author sure imbalances in berries after heavy rains or if the
of the study and a graduate of the Department of berries have been densely packed, half the grapes
Biology in the School of Arts and Sciences at Tufts used were aseptically “injured.”
University. Madden is currently affiliated with Keck
Center for Behavioral Biology at North Carolina The inoculated and unninculated wasps were
State University, Raleigh, NC, and is also post- allowed to forage in enclosures featuring both
doctoral researcher in the Department of Applied injured and intact grapes for a 13-day period. The
Ecology at North Carolina State. “This suggests that grapes were then removed and assessed based on
wasps are playing a role, which had not been previ- a metric system designed to measure disease inci-
ously identified, and may help shed light on more dence and decomposition severity.
effective management strategies or treatments to
curtail these annual losses.” Researchers focused on the presence of black
spores; acetic concentration; and black mold inci-
Wasps are naturally present in vineyards, and in dence. Using the Mann-Whitney U test, researchers
late summer they primarily forage on sugar-rich statistically compared black mold incidence and
foods like ripe grapes. To determine the role wasps berry decomposition scores of uninjured grapes with
were playing in spreading sour rot disease, research- and without wasps.
ers conducted two sets of experiments: one in which
wasps were inoculated with microorganisms associ- Among the Key Findings:
ated with sour rot, and another in which the wasps
were not inoculated with any microorganisms. • There was no impact of wasps on uninjured
grapes.
In order to replicate natural berry splitting, a phe-

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