Growers are encouraged to be on the lookout for these diseases and to call their local cooperative extension office if they need identification help, management recommendations and to report disease.
DOWNY MILDEW
Southeast Farm Press. May 11. 2012: Downy mildew showing up early in cucumbers.
Cucurbit Downy Mildew Found in NC, Rapid Response and Implications for Local Growers.
Frank
J. Louws (1), Wendy Britton (1), Peter Ojiambo (1) and Billy Little
(2). (1) Department of Plant Pathology, NCSU; (2) Cooperative Extension,
Wilson NC.
There
was a confirmed report of cucurbit downy mildew (CDM) in a hoop house
in Wilson County, NC on May 3, 2012. The house contained 2 rows of
trellised cucumbers and about 20 vines had early symptoms. The
infection was about 5% and with actively sporulating lesions.
Wilson
Cooperative Extension, the NCDA, NCSU specialists, and the CDM ipmPIPE
team actively worked to contain this outbreak as soon as possible.
Discussions with the grower, industry representatives, and
state/University employees reached a quick consensus that the best
course of action was to destroy all cucumber vines. The vines were cut,
roots extracted, all debris swept up and placed in plastic bags. The
contained plant material was carried from the greenhouse and buried at
the edge of a field that will not be cultivated this season. This was
completed and verified as of 2:00 pm Friday May 4, 2012.
CES
and industry knowledge about the area suggested field cucumbers were
not present in the vicinity and the inoculum from the hoop house
presented a zero to low risk to the industry as a whole. The CDM ipmPIPE
subsequently changed the status of this outbreak from "confirmed" to
"no longer found". The county in NC will remain on the map but will not
be forecasted as an active source. This data is available at http://cdm.ipmpipe.org.
The
only other recorded incidence of CDM is in south Florida. Based on
recent weather patterns, there is no evidence the inoculum originated
from south Florida and there are no field reports of CDM north of south
Florida. A thorough examination suggested the grower used optimum best
management practices regarding sanitation, removal of all volunteers and
other standard practices. Thus, the source of inoculum remains unknown.
However, early detection, rapid destruction and historical weather
patterns provide high confidence the problem was contained and does not
represent a threat to the industry. At this time, we would not recommend
implementation of spray programs to manage CDM in cucumber fields in
NC. Monitoring of local fields and forecasting spore dispersal from
known sources in south Florida will continue and observations will be
posted at the CDM ipmPIPE website.
To view previous posts on cucurbit downy mildew click here
POWDERY MILDEW
Dr. Tony Keinath, Clemson University Extension Plant Pathologist, sent out a Timely Talk Update about the presence of powdery mildew on watermelons already this season. To learn more go to Early Outbreak of Powdery Mildew on Watermelon in South Carolina.
To learn more about cucurbit powdery mildew click here.
