Cultivation Practices of Coffee

Scientific name: Coffea spp.

Chromosome Number: 2n=22

Basic chromosome no: x=11

Family: Rubiaceae

Center of Origin: Ethiopia

[Center of Origin of C. arabica- Ethiopia, C. canephora- Central Africa; Congo & Zaire]

Figure: Coffee plant, its parts and uses

Introduction:

·         Coffee was introduced into India sometime during 1600 AD from Yemen by Muslim pilgrims BabaBudan on the hills near Chikmangular district of Karnataka, who have 7 Arabica coffee. Primarily, coffee seedlings were planted in the backyards and commercial coffee plantation was done by British entrepreneurs in South India during the 18^th century. Coffee is the 2^nd important beverage and 2^nd among the traded commodities in the global market. At present, coffee is cultivated in 3.14 lakh hectares covering Karnataka (56 %), Kerala (25 %) and Tamil Nadu (9 %). The remaining 10 % area is covered by non-traditional states like Andhra Pradesh, Odisha and North Eastern states. The annual production is around 2.9 lakh tonnes, with an average productivity of 947 kg of clean coffee per hectare.  In world production, 80% is from Arabica coffee, 19% is from Robusta and 1% is from Liberica coffee. In India, Arabica coffee contributes 42%, while Robusta coffee contributes 58% of the total production. The genus coffee consists of 70 species, among which two species are of economic importance. They are: Coffea arabica (Arabica coffee) and Coffea canephora (Robusta coffee)

·         The important difference between the species is described below:

Character	Coffea arabica	Coffea canephora	Coffea liberica
1.      Ploidy level	Tetraploids (2n=44)	Diploid (2n=22)	Diploid (2n=22)
2.      Adaptability	Higher elevation	Lower elevation	Lower elevation
3.      Plant status	A small tree or shrub	Bigger than arabica	Small tree
4.      Leaves	Dark green	Pale green	Big, broad, leathery
5.      Flower bud development	October- March	November- February
6.      Flower opening	9-10 days after receipt of blossom showers	7-8 days after receipt of blossom showers
7.      Berries	10-20 per node, oval in shape	40-60 per node, oval in shape and smaller than arabica	Larger in size
8.      Fruit development period	8-9 months	10-11 months	1 year/ 12 months
9.      Pollination	Self-pollination	Cross pollination
10.  Root system	Comparatively deep	Shallow
11.  Pest and diseases	Susceptible	Tolerant

 

·         C. liberica or the tree coffee is bitter un taste hence used as filler for other two coffee.

·         Caffelite a type of plastic can be made from coffee beans.

 Climate and soil for growing Coffee:

The optimum climate and soil requirement for Arabica and robusta coffee are as follows:

Particulars	Coffea arabica	Coffea canephora
1.      Elevation	1000-1500m MSL	500-1000m MSL
2.      Annual rainfall	1600-2500 mm	1000-2000mm
3.      Blooming showers	March-April (2.5-4 cm)	February-march (2-4 cm)
4.      Backing showers	April-May (5-7.5 cm)	March-April (5-7.5 cm)
5.      Temperature	15-250C	20-300C
6.      Relative Humidity	70-80 %	80-90 %
7.      Shade	Need medium to light shade	Needs uniform thin shade
8.      Soil	Soil should be well drained, slightly acidic in reaction and rich in organic matter content	Same as Arabica
9.      Slopes	Gentle to moderate slope is ideal	Gentle slopes to fairly level fields to be preferred.

Varieties of Coffee:

ü  Crop improvement work carried out at Central Coffee Research Institute, Balahanur, Karnataka has resulted in the release of a number of superior selections in Arabica and Robusta coffee.

ü  The variety of Arabica coffee are:

                        Selection-795              Selection-10                 San Roman

                        Selection -7                 Cauvery

                        Selection -9                 Chandragiri

ü  The variety of robusta coffee (Coffea canephora) are:

                        Selection-274         Selection-3

                        Selection-270

Propagation and nursery techniques adopted in Coffee:

Ø  Coffee is commercially propagated by seed.

Ø  For raising the nursery, the seedbed of 6m x 1m size is prepared by using a mixture of well-sieved forest soil, FYM and sand and the bed should be 15 cm above from the ground level.

Ø  Seeds are sown during December-January at a distance of 2.5-3.0 cm in regular rows and covered with a thin layer of soil. The beds are mulched with paddy straw and watered daily.

Ø Under optimum conditions, the seeds are germinated in about 45 days.  The seedlings at the button or toppee stage (before the opening of cotyledonary leaves) are transplanted into the polybags of 22.5 cm x 15 cm size, which were tightly filled with forest soil, FYM and sand in a 6:3:1 ratio.

Ø  Irrigation is done regularly and occasionally provided with a pinch of urea in polybags. The polybag seedlings attain 5-6 pairs of leaves in about 6 months and become ready for transplanting.

CULTIVATION PRACTICES OF COFFEE

land Preparation for Coffee:

v  Pits of 45cm x 45cm x 45 cm are usually opened after the first few summer showers. The pit should be exposed for weathering for 15-20 days and then closed by using topsoil, FYM/compost @ 1kg/pit, and a small amount of rock phosphate.

v  Healthy and vigorous seedlings 6-8 months old are selected and planted during monsoon (July-September).

v  The plants are planted in the center of the pit, and the surrounding soil is tightly packed.

v  The planted seedlings are provided with cross stakes to prevent wind damage and mulched with dry leaves.

Spacing:

            Arabica coffee: 2-2.5 m x 2-2.5m

            Robusta coffee: 2.5-4m x 2.5-4m

Training and Pruning:

Ø  Training of the bush is necessary to have a strong framework that promotes the production of bearing wood. In India, coffee is trained with a single stem system. When the plant reaches a height of 75 cm in Arabica or 110-120 cm in Robusta, it is beheaded.  This helps to restrict vertical growth and facilitate lateral spreading and increase the bearing wood.

Ø  Pruning in coffee is generally done immediately after harvest and till the onset of monsoon. It is essentially a thinning process and is done mainly to divert the vigour of the plants to certain parts by pruning the other parts.

Ø  Pruning involves:

o   Desuckering:  Removal of orthotropic branches arising from the main trunk.

o Handling: Removal of small shoots growing towards the inner side of the canopy and causing shade. They become unproductive wood.

o Nipping: The growing tip of primary branches is removed to encourage secondary and tertiary branches.

Soil management:

·         To check the serious problem of soil erosion in slopy hills ranges/high rainfall regions, counter planting and terracing are done.

·         For the conservation of soil moisture in coffee plantations, soil stirring (Scuffling) and mulching are recommended.

Shade management:

ü  In coffee plantations, high light intensities and high temperatures occur during the drought period (December-March), so the plants cannot grow properly. Therefore, it is necessary to protect the coffee plants during the above period by providing shade trees.

ü  The most popular permanent shade trees are Albizzia lebbek, Artocarpus integrifolia, Cendrella toona, Ficus glomerata, Ficus infectoria.

ü  Permanent shade trees are generally planted about 12-14 meters apart. It is advisable to plant a large number initially and thin out as the trees grow and spread out.

Soil acidity and liming:

·         Soil pH between 6.0-6.5 is ideal for optimum growth of coffee plants. Liming is recommended for coffee soil with pH below 6.2. Lime can be applied in broadcasting or by soil incorporation any time during the year, provided enough moisture is present in the soil.

·          The best period is November-February and soil incorporation gives better results than broadcasting.

Fertilization:

·         Coffee being a perennial crop, optimum nutritional supply is essential for berry development and fresh wood growth for the succeeding crop concurrently.

·         To get one tonne of clean coffee or above, NPK doses of 120:90:120 kg/ha and 80:60:80 kg/ha is adequate for Arabica and Robusta coffee, respectively.

·         The fertilizers are applied in 3 split doses during the pre-blossom, mid-monsoon and post-monsoon periods.

Weeding:

ü  Generally, weeding is done manually. New coffee plantations are hand-weeded 3-4 times and in established coffee fields 2-3 times a year. Chemical control methods are employed where labour is scarce or expensive. Weedicide like Gramaxone at 1.25 liters in 450 liters of water per hector has been found to be the best.

Irrigation:

ü  It is generally grown as a rainfed crop. But irrigation with sprinklers during March- April increases blossoming and results in higher yields.

Flowering:

Ø  The flowers are fragrant white in colour.

Ø  After bud development, the bud remains dormant until the rain/ wetting/ blossom showers, as the growth of the bud stops before meiosis due to water stress in the bud.

Ø  Flower opens early in the morning and begins to weather after 2 days, leaving the ovary in the stalk.

Ø  Under high-temperature conditions, an abnormal flower called as a star flower with small, fleshy, stiff, and green coloured petals develops, with no functional stamen, that also do not set fruits.

Ø  Flower is pentamerous with small calayx, tubular corolla, epipetalous anther, containing 4 pollen sac, inferior ovary, bilocular ovule and bifid stigma.

Ø  Pollination starts 6 hours after flower opening. The pollinating agents are wind, gravity and bees. Arabica coffee is self-pollinated, while Robusta coffee is cross pollinated due to self-incompatibility in Robusta coffee.

Fruiting:

Ø  Coffee fruit is called as a drupe.

Ø  Duration of flower to fruit set is 7-9 months.

Ø  Fruit is with 2 seeds.

Ø  Pea berry: when there is an abortion of 1 ovule in the fruit, it is a disorder.

Ø  If the berry has 3 seeds, then the condition is known as trilocular ovary or false embryony.

Harvesting:

Ø  Coffee starts giving small yields from the fifth year onwards, while full yield is obtained only after 10-12 years.

Ø  The berries are harvested when they turn red or deep crimson. Arabica coffee attains maturity by September end and starts ripening by October, while, Robusta ripens in December-January.

Ø  Spraying of ether on mature berries @ 0.25-0.35ml/500 ml of water in Arabica and 0.15-2.0 ml/500 ml of water in Robusta hastens to ripen by 2-4 weeks and uniform ripening is achieved.

Ø  Coffee fruit should be picked as and when they become ripe to get better quality.

Ø  Picking is done by hand. The first picking consists of selective picking of ripe berries, which is called fly picking. Thereafter, there will be 4-6 main pickings at 10-15 days intervals and the final harvest i.e., stripping, consists of picking of still remaining green berries on the plant. The collection of dropped fruits during harvest is referred as gleanings.

Yield:

·         An average yield of 1.25 tonnes/ha can be obtained from its crop having moderate plant spread. The yield can be increased up to 2.25-2.50 tonnes/ha from a well-maintained plantation.

Coffee processing:

            The quality of processed coffee is a cumulative index of many characteristics of coffee, such as its appearance in the raw and roast and liquor qualities comprising factors like aroma, body and acidity. Quality can be influenced by nutritional factors and weather conditions during the development and maturity stages of the bean.  Correct processing techniques are necessary to prevent deterioration in quality and to preserve and enhance the inherent qualities of good coffee. Coffee is processed in two ways. They are wet method and dry method. In wet processing, parchment coffee is prepared, whereas in dry method, cherry coffee is prepared. Parchment coffee is favoured by the market. Cherry coffee due to its longer contact with mucilage and fruit skin, is usually associated with a characteristic flavour known as fruit flavour. Hence it is desirable to process most of the produce by the wet methods.

            For the preparation of both parchment and cherry, picking of right types of fruit forms an essential part of processing. Coffee is just ripe when on gentle squeezing the fruit, the bean inside pops out easily. Underripe and overripe fruits cause deterioration in quality. The under ripe fruits tends to produce immature beans, while overripe produce foxy coffee. If it is not possible to pick when it ripens the over and under ripe fruits should be sorted out before separating the fruits for pulping. The under ripe fruits may be dried as cherry.

Preparation of Parchment coffee:

1.      Pulping: Preparation of coffee by wet method requires pulping equipment and adequate supply of clean water. Fruits should be pulped on the same day to avoid fermentation before pulping. Uniform feeding to pulper ensures proper removal of skin and prevents cut. Pulped parchment should be sieved to eliminate an unpulped fruit and fruit skins.

2.      Demucilaging and Washing: The mucilage on the parchment skin can be removed by any one of the following methods- natural fermentation, treatment with alkali and frictional removal with machines.

            Natural fermentation:  The mucilage breaks down in the process of fermentation. It takes more time in cool weather than in warm weather conditions. Over fermentation leads to foxy bean a sour coffee. If under-fermented, sticky mucilage is left on the parchment. This leads to abortion of moisture by the beans and mustiness in the final produce. At the correct stage, mucilage comes off easily and the parchment does not stick to the hand after washing. The beans feel rough and guilty when squeezed by hand. Arabica coffee takes 24-36 hr whereas Robusta takes 72 hours due to thicker and more sticky mucilage.

            Alkali treatment:  Removal of mucilage by alkali treatment takes one hour for Arabica and one and a half to two hours for Robusta. The beans obtained after pulping are drained of excess water and spread out in vats uniformly. A 10 % solution of caustic soda (sodium hydroxide) is evenly applied over the beans and stirred using wooden ladles and trampled by feet for half an hour. About 1kg sodium hydroxide dissolved in 10 litters of water is sufficient to treat about 1500 kg of wet parchment. When parchment is no longer slimy and makes a rattling noise, it is washed with 3-4 changes of clean water.

            Frictional method: Pulper such as Raoeng and Aqua Pulpa which pulp and demucilage the beans in one operation are used. These are suitable for de-mucilage Robusta parchment. This results in bruising of beans. Sorting of fruits into different sizes and uniform feeding using a siphon arrangement may rectify this defect to a considerable extent.

3.      Post fermentation soaking:  If water supply is abundant, parchment may be soaked in water for 12 hours and then given to a final wash. This helps improve the quality of even substandard coffee. Soaking in sodium metabisulphite solution for 24 hours improves raw appearance of the beans.

4.      Drying: proper drying contributes healthy colour to beans and increases quality. The parchment is dried in the sun for 7-10 days to reduce the moisture content to 9.5 %. Initially, beans are dried by spreading in trays to a thickness of 4-7 cm for 24 hours. It is then dried slowly by spreading in concrete floor to a thickness of 7-10cm. stirring and turning over, at least once an hour is necessary to facilitate uniform drying. The parchment is heaped up and kept covered in the evening till morning. At the right stage, beans become crumbly. The bean split clean without a white fracture when bitten between teeth and the dark spots at either extremity of the beans just disappear. Drying is complete if a sample records the same weight for 2 consecutive days. Then it is shifted to stores where it is spread out on the floor for 2-3 days to attain uniform moisture content. The defective beans are sorted out and dispatched to curing works separately.

Preparation of Cherry coffee:

            Ripe berries are spread out evenly to a thickness of about 8 cm drying grounds, preferably tiled or concrete floors. It should be stirred at regular intervals. This has to be heaped and covered with plastic in the evening and spread out in the morning. Cherry is dry when a fistful of cherries produces a rattling sound when shaken. Also when the samples record the same weight on 2 consecutive weighting, drying is complete. Drying takes about 12-15 days. Optimum moisture content for safe storage is 10.5% in Arabica and 11.0% in Robusta. Cherry is bagged in clean gunnies.

Storage: 

Stores should be well ventilated and dry. Bags containing beans should be stored on raised wooden platforms. Label with identity of estate, parchment and cherry should be attached to the bag before dispatch to curing house.

Physiological disorder:

1.      Kondli or Stem wasting: It is a non-parasitic disorder of young plants due to the toxicity of copper. Affected plants show constriction of stem at the first or second node from the collar, followed by thinning of the lower part and swelling of the upper part. The apical leaves show deep copper bronze or yellow colour. The seedlings become lean and lanky and break off at the constricted portion.

Control measure: Copper fungicides are to be replaced with Dithane or Febam in plantations where its symptoms appear.