Many Topics Discussed in Salinas
Patrick Cavanaugh, Editor
Steve Koike, UC Cooperative Extension Farm Advisor, plant
pathologist, opened up University of California Cooperative
Extension—Monterey County 2013 Plant Disease Seminar talking
about new soil born diseases affecting strawberries.
said the new soil born disease problems surfaced in 2006 in Ventura and Orange
Counties where they stopped using the traditional Methyl Bromide/Chloropicrin
fumigation application. That’s when the problems arose, such as Charcoal Rot, or
Macrophomina, as well as Fusarium.
that Macropomina and Fusarium are bad news for the industry because
they are so damaging to strawberries, easily spread from field to field and may
be a long-term challenge. There are no truly resistant strawberry cultivars,
alternate fumigants are not completely effective, bed fumigations are insufficient
and post-plant fungicides do not work.
are trying to produce cultivars with resistance to these diseases.
Krishna Subbarao, a UC Davis Plant Pathologist reported
that Verticillium wilt is spreading throughout Monterey County. It was
discovered in 1995 on lettuce in the Watsonville area and made its way to
Salinas Valley 6 years later, and eventually to Kings City.
|Plant Disease Crowd|
has reached new highs, new areas, and with increased losses. Subbarao and his
team are trying both to identify all the different species of Verticillium through
DNA testing and to breed Verticillium resistance into lettuce cultivars.
Trevor Suslow, UC Extension Research Specialist
with statewide responsibilities in food quality and safety, spoke about
emerging produce safety issues regarding human parasites and viruses.
equipment at UC Davis can help eliminate false positives of pathogenic toxigenic
E. Coli possibly eliminate a recall on products.
|Trevor Suslow and Drew Mather|
subject of Listeria, Suslow reported that the more likely point of entry for Listeria
is the processing and handling environment and not really the product. It is
seen in product tested after its use-by date, as Listeria has the ability of to
grow in refrigerated storage over long periods of time.
has shown that Listeria numbers fall off very quickly, 32 days, after a field
Alec Gerry, Associate Professor and Extension
Specialist UC Riverside discussed protecting leafy greens from contamination
with Filth Flies, also known as bottle, blow or garbage flies.
carry E. Coli from a manure source such as a dairy into a lush field of lettuce
and contaminate the crop. Desiring sugar (carbohydrates), the insect seeks to
find it in a field where honeydew secretion has been left by other insects.
suggested growers plant a tree line barrier, place stinking bottle traps on the
fence line, improve fly attraction with better odors and develop screens to deter,
catch or kill the Filth flies.
|Tatiana Simkova and Steve Klosterman |
Steve Klosterman, USDA Research Molecular Biologist,
spoke about the spinach’s primary disease, Downy Mildew (DM). Fungicides
effectively control DM in conventional fields; organic growers rely on
resistant varieties, but the breeders may not be able to keep up.
lab is working on specific detection and quantification of DM. Knowing what DM races
are present may prevent spraying, thus avoiding resistance.
For extended coverage on this meeting, see upcoming issues of Vegetables West Magazine.
Labels: 2013 Plant Disease Conference, Downy Mildew, Filth flies, Fusarium, Macrophomina, Salinas plant disease conference, Verticillium wilt