Coffee disease
Coffee trees are pruned short to
conserve their energy and aid in harvesting, but can grow to more than 30 feet
(9 meters) high. Each tree is covered with green, waxy leaves growing opposite
each other in pairs. Coffee cherries grow along the branches. Because it grows
in a continuous cycle, it’s not unusual to see flowers, green fruit and ripe
fruit simultaneously on a single tree.
All commercially grown coffee is from a region
of the world called the Coffee Belt. The trees grow best in rich soil, with
mild temperatures, frequent rain and shaded sun.
But there are some
problems or disease found in coffee. Many disease
grows in coffee tree. Some types of disease are given below-
Anthracnose
Generally
found in the eastern part of the United States, anthracnose is caused by fungi
in the genus Colletotrichum, a common group of plant
pathogens that are responsible for diseases on many plant species. Infected
plants develop dark, water soaked lesions on stems, leaves or fruit. The
centers of these lesions often become covered with pink, gelatinous masses of
spores especially during moist, warm weather. Anthracnose can reduce a
beautiful harvest into rotted waste in just a few days.
Control
Remove
and destroy any infected plants in your garden. For trees, prune out the dead wood
and destroy the infected leaves.
You can
try spraying your plants with a copper-based fungicide, though be careful
because copper can build up to toxic levels in the soil for earthworms and
microbes. For trees, try a dormant spray of bordeaux mix.
Algal (red) leaf spot
Algal
leaf spot is a foliar disease most commonly seen in warm humid climates or in
greenhouses. The causal organism is Cephaleuros virescens, a green parasitic alga whose usual hosts are
plants with leathery leaves such as cotoneasters, magnolias, hollies,
rhododendrons and viburnums. Algal leaf spot is
sometimes called green scurf because the spots may have a crusty, fuzzy or
flaky appearance.
Control
Keep plants as healthy as possible, as
well-managed plants are less susceptible to disease. Maintain proper soil
drainage and water, and fertilize as needed. Prune plants to improve air
circulation and access to sunlight. Trim around the plants to reduce the
humidity level, including overhanging trees that create too much shade. Rake up
and dispose of leaves and debris under and around the affected plant. Discard
of infected debris carefully to prevent spread of the disease. Keep in mind
that the algae can survive on fallen leaves during the winter months. Water at the base of the plant. Avoid wetting the leaves as
much as possible. Apply a Bordeaux mixture or copper-based fungicide if the
plant is seriously infected. Repeat every two weeks during cool, damp weather.
Armillaria root rot
Armillaria root rot is a fungal root rot
caused by several different members of the genus Armillaria.
The symptoms are variable depending on the host infected, ranging from stunted
leaves to chlorotic needles and dieback of twigs and
branches. However, all infected hosts display symptoms characteristic of being
infected by a white rotting fungus. The most effective ways
of management focus on limiting the spread of the fungus, planting resistant
species, and removing infected material. This disease poses a threat to
the lumber industry as well as affecting recreational areas.
Control
Sadly,
there is no absolute treatment for Armillaria root
rot. The disease can be managed by consistent removal of dead trees and
infected stumps. Armillaria requires consistent
moisture to survive, and in citrus groves, excavation around the root crown has
been an effective deterrent but not an ultimate cure. Providing excellent care
to trees has been shown to increase vigor and health, thereby reducing the plant’s
symptoms.
Brown eye spot
Brown eye
spot and berry blotch are common disease of coffee. The brown eye spot is a
disease commonly noticed in nurseries. The disease causes brown spots on leaves
gradually expanding with reddish brown margin. Affected leaves turn yellow and
premature defoliation of such leaves takes place. Brown sunken lesion on green
berries surrounded by a bright red ring is also noticed.
Control
In the
nursery, grow plants under pendal shade to avoid
exposure to sun light.
In the estate,
young plants should be protected by ‘hutting’ to avoid the exposure.
Provide
adequate mulch to conserve soil moisture.
Protect
the plants in the nursery by spraying organic fungicides if the disease is
noticed.
Spray Captan or Dithane M-22 or Ferbam etc., at 0.4% a.i.
(5 g/1) or Foltaf 80 WP (captafol) at 0.3% a.i. (3.75 g/l)
once in 30 days interval.
In the
new clearings maintain good overhead shade and spray 1.0% Bordeaux mixture, if
incidence is observed.
Collar rot
Collar
rot is an important nursery disease of coffee. The disease is mainly seen in
seedlings of 1 -3 months age in the nursery. Seedlings show brownish discolouration on the stem near the ground level leading to
rotting of the tissue. Growing apex wilts and the seedlings collapse and die.
Control
Expose
the nursery soil to the sun for 2 to 3 months.
Prepare raised seed beds adding compost and
sand (2:1) to provide good drainage
of excess moisture from seed beds.
Avoid
excessive watering.
Avoid overcrowding of seedlings by proper
spacing of seeds while sowing.
Provide filtered overhead shade using coir
mats.
Remove
and destroy the affected seedlings by burning to prevent further spread.
Die-back
Coffee needs one leaf
pair to support five to six berries through to maturity. If there are too many
cherries and not enough leaves, all the food goes from the leaf to the
developing cherry. Leaves then drop off, causing dieback. Some varieties,
especially dwarf Catimors, are more susceptible to
this condition. Loss of leaf depletes plant carbohydrate reserves resulting in
weakened plants.
Control
Once the
problem exists it is very hard to break the cycle if it is left too long.
Maintain good plant health. Maintain good shade (50%). Plant only recommended
varieties. Use a well-balanced fertiliser programme and apply adequate nitrogen and potassium as
recommended earlier.