Diagnosing the Deficiencies and Toxic Elements in your
"Sick" Hydroponics
Garden
Hydroponic gardeners may have a unique way to raise their
crops but their plants are still susceptible to many plant diseases commonly
found in plants that grow in soil. Typical
diseases that affect hydroponic gardens are fungal or humidity related. While there are plenty of chemicals available
on the market to treat these diseases you will still need to know how to
diagnose your sick plants in your hydroponic garden.
The most common sicknesses in hydroponic plants are related
to the leaf. Recognizing these common
problems when they occur will help you take the right action in treating your
sick plants. Rust is a problem that
affects the leaves of a plant and there are over 5,000 varieties of this
fungus. It is identified initially as
yellow spots on the leaves. If not
treated the spots will grow larger and turn into reddish brown elevated lesions
that contain orange powdery spores. The
treatment is simple though. Pick off the
affected leaves and dispose of them outside of your grow room; do not compost
these leaves or you risk infecting other plants. Sulfur or copper sprays should be used on
infected plants weekly and throughout the growing season; avoid spraying during
hot weather.
Powdery mildew is another common fungal disease that affects
plants in hydroponic gardens. This
disease is identified as blister-like lesions that form on the leaves. The leaves begin to curl and a white or gray
powdery substance appears on the upper parts of the leaves on the infected
plant. This disease predominantly
affects new growth on plants. Watering
the diseased plants in the morning so that their leaves have a chance to dry
thoroughly can control this fungus. All
diseased plant debris that has fallen off must be removed; do not compost the
diseased leaves. Copper or sulfur sprays
can help stop the spread of this fungus when used weekly. Instead of removing the affected leaves, they
can be washed in the morning, which will disrupt the spore producing cycle.
Blossom end rot is another common disease but it is not
caused by fungus. It commonly affects
tomatoes, peppers and eggplants. The
cause of this disease is insufficient calcium when the plant is budding. The rot can occur on both green and ripe
fruits. Dark brown spots on the end of
the fruit identify this disease. Keeping
plants evenly moist and spraying foliage with kelp or calcium can treat the
disease.
The downy mildew fungus appears on the leaves of plants as yellow
or white spots. The spots are visible
after heavy dew or rain but tend to disappear after prolonged sunny
weather. As the disease progresses the
leaves will turn brown and fall off the plant.
Spore production is increased in temperatures cooler than 65 degrees
Fahrenheit or humidity higher than 100 percent.
Insects and dirty garden tools can carry the disease so cleaning your
tools frequently can help stop the spread of the disease. Avoid overhead watering of plants infected
with downy mildew. Treat infected plants
with a copper spray every week until harvest time.
Mosaic disease is a viral disease that attacks tomatoes,
roses, beans and peppers. The disease is
often misdiagnosed as a nutritional deficiency.
Green or yellow stripes or spots are symptoms of this disease. Leaves can be wrinkled or curled, growth of
the plant is stunted and fruit will have bumps or wart-like areas. There is no cure for viral diseases so the
best control is keeping the virus from entering your garden. Do not clone these plants, as they will carry
the disease. Treat plants with
insecticidal soaps because insects carry the disease.
More information on plant diseases and treating them can be
found at your local library or on hydroponic gardening websites on the
Internet.