DISEASE AND PEST OF COFFEE

BY

DENNIS OWUSU BOATENG (TECHNICAL OFFICER)  
BUNSO COCOA COLLEGE (GHANA COCOA BOARD)
0240296835

MAJOR DISEASES OF COFFEE

COFFEE LEAF RUST

•       Leaf rust of coffee is caused by the fungus Hemilela vastatrix. 

•       This disease is widely spread throughout all coffee growing countries. 

•       The disease was first found in Kpeve in 1953 and consequent loss of crop.

SYMPTOMS

•       About three weeks after infection, first symptom appears as pale green spots on the upper side of the leaf.  Later bright orange powdery substance appears on the leaf. 

•       This crumb together to cause bigger irregular-shaped structures called pustules which sometimes spread across the whole leaf surface.

•       Very severely affected plants suffer from premature loss of leaf and die-back making room for invasion by secondary parasites

CONTROL

•       Copper-based fungicides like Kocide 101 and Cacaobre should be sprayed.  It is best to spray about the time the rain breaks.

COFFEE BERRY DISEASE

•       The coffee berry disease is caused by the fungus Colletotrichum coffeanum.

•       The fungus can attack both the leaves and the berries in all stages of their development and under special conditions the young wood of bearing branches as well causing a die-back.

SYMPTOMS

•       On both ripe and unripe berries the first sign of attack is the appearance of a small, dark, sunken lesion that spreads rapidly, eventually covering the whole berry.

•       The deeper tissues, including the beans are also invaded, and the berry is soon reduced to an empty black “mummy”.  In severe attacks all or almost all the berries mummifies but do not fall off; the bearing branches resemble sooty black ropes.

•       When a ripe berry is attacked, although development of the lesions is rapid, the fruit is often harvested before the bean is difficult to process and some may lose value.

CONTROLS

•       For effective control of berry disease, efficiency of spray application is of supreme importance.  For effective control, it must be sprayed to run-off at high pressure and high volume.

•       Of the many types of fungicides tested, only copper compounds like Kocide 101 and Cacaobre give effective and consistent results.  Effective control of berry disease is secured by 3 spraying at intervals of 3 weeks during the period of maximum growth, normally from Mid-February to April.

DAMPING-OFF

•       This is a nursery disease which can be caused by several species of fungi.  Entry is through the very thin cuticles which seedling develops when grown under lamp, poorly lit conditions.

–      There are two types of damping-off disease:

•       Pre-emergence damping-off in which the fungus attacks the seed just before or after germination to cause decay in the soil.  The seedling therefore fails to appear above ground.

•       Post-emergence damping-off in which the fungus attacks the young seedling at or slightly above level causing rot and eventual collapse and death of the seedling.

CULTURAL CONTROL

•       Seed-beds can be built high and well drained

•       Avoid excessive watering.

CHEMICAL CONTROL

•       If damping-off is a problem drenching of seed-beds with Kocide at 150g in 13.6 litres of water is effective.

•       Spray emerged seedling with a copper-based fungicide such as Kocide at 150g in 13.6 litres of water.

MINOR DISEASES OF COFFEE

GREY RUST COFFEE

•       Casual Organism:             Heomileia coffeicola

•       Symptoms:  it occurs irregularly ever the leaf with grey powdery substance in clumps on the undersurface.

•       Control:  Spray copper-based fungicides like Kocide 101 and Cacaobre.

BROWN-EYE SPOT OF COFFEE:

•       Casual Organism:             Ceorcospora coffeicola

•       Symptoms:  Causes brown spots on leaves usually with reddish brown margins.

•       Control:  Use of copper-based fungicides like Kacide 101 and Cacaobre

DIE-BACK COFFEE

•       Die-back is a physiological condition in which the tips of fruiting branches die-back and lose leaves due to over-bearing.

•       Control:  Part or the entire crop can be stripped to prevent serious damage and this is advisable on trees bearing their first crop.

INSECT PESTS OF COFFEE

NAME OF INSECT/AFFECTED AREA	NATURE OF DAMAGE	CONTROL
LEAF       1.  Oecophylla spp            (Red ants)	Acts as nuisance during harvest and other cultural operations.  It fastens the leaves together by webs.	By spraying highly residual insecticides such as Gamalin and unden
STEM       2.  Bixadus sierricola            Coffee stem borer	Larvao penetrate the stem and cunnel upwards and downwards and even to the main branches.  The galleries normally get infected by parasitic fungus.	Insertion of wire in the      gallery to scare or kill      the larvae. 2.  Fumigation of holes. 3.  Use of contact      insecticides mixed with      stickers. 4.  Remove effected plants      and destroy them.
.  Xyloborus             morstatti	Larved burrow into the stem.  This attack leads to interruption of sap movement.	Same as above.
FRUIT       4. Stepharodores            hampei           (the coffee berry           borers)	The nymphs puncture the immature berries which are subsequently invaded by fungi particularly Namatospora spp.	1.       Pruning should be done to reduce humidity in Plantations. 2.  The use of systemic       insecticides are       recommended
Antetiopsis spp.	The nymphs puncture the immature berries which are subsequently invaded by fungi particularly Namatospora spp.	1.       Pruning should be done to reduce humidity in Plantations. 2.  The use of systemic       insecticides are       recommended
1.       Virachola spp Coffee berry butterfly	The larvae feed on flesh and seed of berry creating large holes	1.       Removal and      destruction of         infected berries. 2.       If the berry is ripped, hot water treatment after harvest is recommended
ROOTS       7.  Mealybugs	They attack the roots occasionally killing the young plant.	1.       Control aims at killing       the attendant ants of       mealybugs 2.  The plant should be      uprooted and      subsequently      replaced
Brachytrupes             membranaceus	Attack young seedlings in coffee nurseries and drying plants	Locate position in the soil and treated the soil with residual insecticides.

References:

·         Allen, Stewart Lee (1999). The devil's cup : coffee, the driving force in history. Soho: Random House. ISBN 1569471746. 

·         Bersten, Ian (1999). Coffee, Sex & Health: A history of anti-cofee crusaders and sexual hysteria. Sydney: Helian Books. ISBN 0-9577581-0-3. 

·         Clarke, Ronald James; Macrae, R, eds (1987). Coffee. 2: Technology. Barking, Essex: Elsevier Applied Science. ISBN 1-85166-034-8. 

·         various (1985). "Botanical Classification of Coffee". In Clifford MH, Wilson KC. Coffee: Botany, Biochemistry and Production of Beans and Beverage. Westport, Connecticut: AVI Publishing. ISBN 0-7099-0787-7. 

·         Ganchy, Sally (2009). Islam and Science, Medicine, and Technology. The Rosen Publishing Group. ISBN 1435850661. 

·         Jacob, Heinrich Eduard (1998). Coffee: the epic of a commodity. Short Hills, N.J.: Burford Books. ISBN 9781580800709. http://books.google.com/?id=bdxpPwAACAAJ&dq=coffee+epic+of+a+commodity&cd=1.