LABELLE, FLORIDA -- Hendry County Agricultural Agent Gene McAvoy has
sent a letter to area farmers warning that Glades Crop Care has
reported a confirmed finding of late blight on tomatos in the
Immokalee area. The infection is in a fairly large planting which
has multiple infections widely scattered throughout the
field. Numerous infected plants are present with symptoms ranging
from single lesions to several hotspots throughout the field where
plants display multiple late blight lesions. McAvoy says the disease
can easily devastate a tomato or potato field within a few weeks if
it is not properly controlled.
Since the disease can spread so rapidly, growers are being warned to
scout their fields thoroughly each day, especially when cool and wet
conditions conducive to disease development prevails. Since late
blight symptoms may be confused with symptoms of other diseases,
McAvoy gave farmers several diagnostic pointers to help growers
distinguish between the late blight and other diseases.
Numerous fungicide products are registered for late blight
control. Protectants, as the name implies, protect foliage from
infection by spores. Protectant chemicals must be well distributed
over the leaf surface and must be applied before spores land on
leaves. They are ineffective against established infections.
In Florida, it has been observed that seldom does a widespread late
blight epidemic occur on tomatoes in the Manatee-Ruskin area unless
the disease was present in the Immokalee area and/or Dade
County. Since late blight has been confirmed on tomato in Immokalee,
growers in other areas are being advised to adhere to a preventative
spray program. Growers are advised to be aware of the presence of the
disease in SW Florida and should be alert for the appearance of
symptoms in their fields as well as be sure to apply protective
fungicides to help prevent possible infections. No other disease
will find an unprotected field as rapidly as late blight.