Agriculture Reference
In-Depth Information
to help prevent the spread of disease. If you are working in a situation where tools are being shared, this
point cannot be over emphasized. If tools aren't disinfected and they are used by multiple gardeners,
they will be disease carriers.
Here are a few common diseases that your gardeners might see in the summer growing season, along
with their symptoms and methods for treating them.
Okay, enough about disease and pests! If your gardeners encounter problems that can't be identified
or successfully treated, contact your county extension service. Trained horticultural experts can assist
with garden problems, or enlist a Master Gardener who is especially knowledgeable in this area.
Common Diseases
Problem
Description
Organic Antidote
Blossom
end rot
Blossom end rot can affect tomatoes, peppers, squash,
and other fruiting vegetables but is most prevalent in to-
matoes. It's caused by a calcium deficiency in the fruit
and often occurs due to erratic weather as the fruit begins
to set (if the plant gets too dry or too wet, its ability to ab-
sorb calcium from the soil is diminished). Blossom end
rot is most often seen on the first fruit of the season as
dark brown, leathery, sunken spots on the blossom (bot-
tom) end of the fruit.
Pick and discard damaged fruit in
the trash (and rest assured this
isn't a life sentence for your
plant—subsequent fruit probably
will turn out just fine). Help pre-
vent onset by watering attentively
and trying to maintain a consist-
ent moisture level in your
soil—gardeners might try adding
a layer of mulch. Watering deeply
a couple of times a week is more
effective than watering superfi-
cially every day.
Powdery
mildew
Powdery mildew is a fungal disease that favors squash,
cucumbers, and melon foliage. It's usually caused by
conditions of high humidity, crowded plantings, or poor
air circulation. You'll recognize it as powdery splotches
of white or gray, most often on the top surfaces of leaves
and stems of plants, and at times on lower leaf surfaces,
flowers, buds, and fruit. Powdery mildew isn't fatal, but
if enough of the plant is covered, it can become stressed
and fruit quality can diminish.
Trim off any infected plant parts
and discard them in the trash. Im-
prove air circulation by thinning
and pruning as appropriate, and
make sure to water under foliage,
not on top of it.
Tomato
blight
Many tomato diseases are lumped into the category of
blight—early blight, late blight, and septoria leaf spot, to
name a few. If your plant's leaves suddenly have brown
curly edges, dark lesions, or bull's-eye splotches with
concentric rings, take a photo of the infected foliage and
compare it to images you find online or in a topic. It's
normal for leaves to dry out as a plant ages, so research
is important to determine whether a plant is indeed infec-
ted. Blights are fungal diseases and can spread quickly
to fruit and other plants. Sometimes blight can return the
following season since the fungi live in the soil. Encour-
Remove affected plant parts and
throw them in the trash. Garden-
ers can try applying a commer-
cially available hydrogen perox-
ide solution to help kill the
fungus, if it has only infected
small areas of the plant. Overly
wet conditions can encourage
blight. Preventive techniques in-
clude proper watering and spa-
cing plants to allow enough air-
