Plantation crops : Coffee

Coffee is cultivated commercially in the four southern states of Karnataka, Tamil Nadu, Kerala and Andhra Pradesh. It is also grown on a limited scale in some non-traditional areas of Orissa, West Bengal, Assam and Madhya Pradesh

Arabica (Coffea Arabica) and Robusta (coffea canephora) are the two principal economic species extensively cultivated in India. While 90,211 hectare area (57.98%) is under arabica, 65,365 hectares (42.02%) are under robusta. India produces 85,000 to 100,000 tonnes of coffee and earns considerable foreign exchange. The details in respect of the area are given below:

Coffee cultivation is confined to the hilly areas of the Western and Eastern Ghats. The annual rainfall ranges from 1250 to 3000mm. A major portion of the area is under the south-westerly monsoon and only a small area is under north-easterly monsoon. This plant grows well at temperatures between 12 and 36 degrees celcius. Elevation above the sea level influences the quality of the coffee. Coffee arabica grows well at elevations between 900 and 1200 metres; Coffee canephora or robusta grows luxuriantly at the lower elevations (about 150 metres). Arabicas are more shade-loving than robustas under conditions in south India.

SOIL. Coffee soils in India belong to the red and lateritic soils. The soils differ in texture from sandy loam to clayey loam. Red ferruginous clays occur in tracts e.g. Bababudangiris in Karnataka and the Nilgiris in Tamil Nadu. They have good aggregating ability and are generally well-drained. They are rich in organic matter and are acidic to neutral. The total soluble salts are well below the sensitivity limits. They are well stocked with potassium but low in available phosphorus. They are also poor in calcium, and magnesium. They respond well to liming, manuring and other soil management practices.

CLIMATE. Climatic and environmental factors, like rainfall, temperature, elevation and aspect can influence the economic production of coffee much more than soil factors. Under conditions in southern India, summer temperatures combined with poor subsoil moisture can be a severe limiting factor, whereas at northern latitudes cold winter temperatures can be equally limiting.

The major climatic factors that affect arabica and robusta are:

VARIETIES. There are six commercially important varieties and selections of c.arabica grown in India.
1.’old chiks’
2.’coorgs’
3.’kents’
4.’s.288′
5.’s.795′
6.’s.1934′.

Old Chiks. The earliest strain of C.Arabica to come under cultivation owes its name to Chikmagalur where it was initially grown. It is a tree of coarse growth, with branches having an upward turn and foliage of pale color. Leaves are small and narrow, 15 cm in length. Fruits are red, beans are bold. The produce is reputed for its high liquoring quality. Heavy crops in alternate years appear to be a regular feature. The plant is highly susceptible to leaf rust.

Coorgs. is thought to have originated in Nalaknand area of Coorg, in about 1870. It has a graceful drooping margin. The fruits are bold , oblong and red. It is highly susceptible to leaf rust.

KENTS. developed by L.P.Kents of Doddangudda and Kalagnee estates in Mudigree zone was cultivated during 1918-1920. It is resistant to races II and VII of leaf rust. Leaves are larger than ‘coorgs’ , dark green and thick. Apical leaves are dark bronze. Fruits are red. Beans are bold, oblong and larger than those of ‘coorg’.

‘Kents attracted the attention of the coffee growers in India. The strain was also introduced in certain African countries. This is high yielding , capable of withstanding higher temperatures and tolerant to leaf-miner. many strains are susceptible to the die-back disease (stem-pitting). It has higher resistance to this disease than ‘Bourbon’. ‘Kents’ has lower keeping quality. It is being cultivated in India because of judicial spraying and periodical pruning.

‘S.288’. Released in 1938, it is the first-generation progeny of ‘s.26’, a hybrid from Doobla estate (Western Karnataka). Its fruits are round and oblong, coated, blue to grey. its liquoring quality is like normal arabica. 75% of the plants are resistant to races I and II of the coffee rust.

‘S.947’. This variety(in the second generation) has been found to be homozygous for resistance to races I and II of the coffee-rust. It is preferred in Mudigere and Saklaspur zones.

‘S.333’. It is the first filial generation (F1) of a cross between S.31 and S.22. Plants are vigorous and spreading. Fruits are bold-medium , round to oblong. About 10 % of the seedlings may show temporary chlorosis(absence of chlorophyll in the leaves) in the second or third pair of leaves. About 75 % of the plants are resistant to races I and II of the leaf rust.

‘S.795’. Released in 1946, it is the F2 of S.288 of ‘kents arabica’. Some plants are initially semi-erect but droop as they grow.

Fruits are oblong with a small to broad navel flush and sometimes with persistant calyx. Beans are bold, larger than of ‘S.288’ and are coated or bluish grey.

‘S.1934’. (F4 of S.288 of ‘kents arabica’) was established in 1960-61. They have fruits and seed characters similar to those of kents. The rest of the characters are like ‘S.795’. They have a lower triage (false polyembryony). Yields are satisfactory.

ROBUSTA. Coffee canephora Pierre ex Horn (2n=22) is a bigger tree than arabica, with broader and larger leaves. Leaves are pale green, flowers are white and frogarant.They are borne in large clusters than those of arabica. Berries are small, but per node they are more numerous varying from 40-60 or more.

Under the soil and climatic conditions of south India the buds appear during Nov to feb. Rains in Feb-Mar are ideal for blossoming. The flowers open on seventh or eighth day after rains. Unlike arabica, Robusta is self-sterile and hence it is cross-pollinated. The fruits mature in 10-11 months. They are harvested 2 mths after arabica.

TREE COFFEE. Coffee liberica Bull ex Hiern (2n=22) is a large tree bearing broad, dark green, leathery leaves 2-3 times larger than those of arabica.

CROSSES. Cioccie and Agaro crossbred seperately with ‘S.1934’ give good yields.

Devamachy of S.881 arabica is a spontaneous C. canephora of C.arabica spotted in a private estate in Coorg. S.881 is a collection from Rume Sudan and was established at the Central Coffee Research Institute in 1944. The parent plant in Devamachy is an intermediate plant with higher resistance to rust. beans are uniformly small. The liquoring quality is of arabica type.

‘S.274’. robusta of ‘Kents’ arabica. Seeds from the selected F2 progeny of BC2 with arabica given for trial show variation from arabica to intermediate type of plants. The progeny shows an early floral phase like robusta and spreading habit like arabica. The pulp is like arabica or robusta. the bean size is variable , it is thicker as in robusta . It is mostly coated , grey, green or a mixture of the two.

Dwarf hybrids (San Ramon hybrids). established in Brasil, it has compact internodes. Seeds obtained from a cross between dwarf of s.795 of Agaro are being tried in the field. The progenies from the dwarf hybrids produce 70% dwarfs . Dwarfs of San Ramon x s.795 x Agaro , Cioccie produced dwarfs of larger size and erect branches giving an open type of plant habit. They are drought resistant and yield good crops.

Hibrido de Timor. is a spontaneous cross of robusta x arabica from Timor supplied by the Coffee Rust research centre, portugal. Very few plants are susceptible to races XXII,XXV,XXVI. The progenies show a high variation in morphological characters.

Planting. The soil used for raising seedlings should be rich in organic matter, free from nematodes, cockchafer larvae and wireworms. Farmyard manure, sand and lime are also important ingredients of the soil.

The seed is treated evenly with Agrosan at 20 kg per forlit before sowing. This protects the soil against fungal infection during germination.

A seedbed raised to a height of 15 cm, usually about 1 metre in width and of convenient length is prepared. Four baskets of fully decomposed cattle manure or compost, about 2 kg of finely sieved lime and 400 g of rock phosphate are incorporated into a bed 1mx6m. If heavy soils are used it is necessary to add coarse sand to facilitate drainage and aeration.

Seeds should be sown in December or January. the seeds are placed on the soil surface 1.5-2.5 cm apart in regular rows. A thin layer of fine soil is used to cover them. The bed is then covered with about 5cm of paddy straw to ensure an even temperature and prevent the soil surface from drying. The beds are watered daily and protected from sunlight by an overhead pandal. The seeds germinate in 45 days.

PLANTING IN THE FIELD. Disease-free and vigorous seedlings are selected for planting. Rooted plants 16-18 months old , with and without balls are planted during June and the ball and bag plants are generally planted from September to October. The seedling is placed in a hole made in the pit, with its tap root and lateral roots spread out properly. The hole is then filled with soil. The seedlings are provided with cross-stakes to prevent damage from winds.

Ball and bag seedlings are planted towards the end of the monsoon rains and with the commencement of north-eastern rains i.e. in september. First the bottom portion of the bag is cut and the tap root nipped. The seedling is gently removed from the bag and placed into the hole. The hole is covered with soil and the plant is firmly fixed.

PLANTING SHADE TREES. Dadap is commonly used as a lower canopy shade tree. 2 metres long stakes are fixed for every 2 plants of coffee. Silver oak and dadap are planted during june when the rains commence. During the dry season the stems of the young dadap are either painted with a dilute solution or wrapped up in agave leaves to protect them from sun-scorch.

After care

1.The clearing should be well fenced to prevent damage to coffee and dadap from stray cattle.

2. The plants should be protected against cockchaffer attack during the first 2 years by applying Lindane or granular insecticides around the seedlings.

3. Weeds should be eradicated in the very first year.

4. the soil around the seedlings should be properly mulched and the plants provided with shade.

5. No manure needs to be applied till may-june of the following year. Sprinkler irrigation may be given.

6.It is advisable to spray a Bordeaux mixture along with urea and potash during december to protect against pests and disease.

7. A manurial schedule should be followed from the second year onwards.

8. Plant protection measure should be adopted meticulously.

NUTRITIONAL REQUIREMENTS.

Coffee is a perennial crop and the tree has the dual function of maturing the berries and producing fresh wood for the succeeding crop. One tonne of clean coffee removes from the soil 34 kf of N, 5 kg of P2O5 and 45 kg of K2O in case of robusta varieties. Considerable nutrients are also lost through leaching under a heavy rainfall and as a result of fixation and immobilization of nutrients in the soil. Such a depletion may lead to the impoverishment of the soil. It is thus essential to replace the lost nutrients by using fertilisers.

The basic requirements of fertilisers are given in Table 3. these are subject to revision in respect of individual estates, based on soil and plant analysis, soil type, intensity of shade and the productive potential of the block.

SHADE AND SHADE MANAGEMENT

A shade tree should be fast-growing and spreading to allow a uniform amount of filtered light . Its root system should be deep so that it does not compete with the coffee plant for food and moisture. the trees, which serve as alternative hosts to the major insect pests of coffee must be avoided.

Dadap (Erythriana lithosperma) is by far the universal temporary shade-tree in India. It is always planted with coffee in the clearings. It is easily raised from stakes, has very quick growth, stands frequent loppings, regenerates very quickly and is a legume.

permanent shade trees are generally planted about 12 to 14 m apart. It is desirable to plant a large number at first and gradually thin them out. They should have their canopy about 10 to 14 m above the coffee plants. Shade trees require constant attention by pruning and lopping to furnish the required shade.

Shade trees are usually raised from seeds and also from stakes. Seedlings are grown in the nursery for a year before being transplanted in the soil.

HARVESTING AND PROCESSING

Quality is a summative index of many characteristics of coffee, such as its appearance in the raw, roast tastes and its liquor qualities comprising factors like aroma , body and acidity. Quality can be influenced by nutritional factors and weather conditions during the development stages of the beans. Correct processing techniques are essential to prevent deterioration in quality. Coffee is processed in two ways:
(a)wet processing by which plantation or parchment coffee is prepared, and
(b)the dry method by which cherry coffee is prepared.

Parchment coffee prepared by using the wet method is generally favoured by the market. Cherry coffee, due to its very nature of preparation and longer contact with the mucilage and fruit skin, is usually associated with a characteristic fermenting flavour.

Harvesting. For the preparation of both parchment and cherry types of coffee, picking of the right types of fruit forms an essential part of processing. Coffee is picked when the fruits are just ripe. Under and over-ripe fruits cause deterioration in quality, the former gives “immature beans” and the latter “foxy” coffee. They may be dried seperately for making cherry coffee. the bags used are frequently washed and dried. Bags in which fertilisers, pesticides and fungicides are stored should never be used for this purpose.

Preperation of parchment coffee

PULPING. The preperation of coffee with the wet method requires pulping equipment and clean water supply. Fruits are pulped on the same day to avoid fermentation. The pulper should be checked everyday to prevent cuts. The pulper-nipped beans and other deformed beans will result in defective parchment.

Fruits may be fed into the pulper through a sipho arrangement to ensure uniform feeding and to seperate lights and floats from sound fruits. Uniform feeding ensures the proper removal of skins and prevents cuts, choking of the pulper etc. The pulped parchment should be sieved to eliminate any unpulped fruits and skins.

The skins seperated by pulping are led away from the vats into the collection pits, so that their microbial decomposition will not affect the bean quality when they get mixed with the bean.

DEMUCILAGING AND WASHING. The mucilage on the parchment skin can be removed by using any one of the following methods: (a)natural fermentation, (b)treatment with alkali, and (c) frictional removal in machines like ‘Raoeng’ and ‘Aqua pulpa’.

Natural fermentation is the most commonly used method for demucilaging coffee. The mucilage breaks down in the process of fermentation. In the case of arabica, it is complete in 24 to 36 hours. Fermentation takes longer in cool water than in warm weather. If the parchment is under fermented, the sticky mucilage is left on the parchment. This condition leads to the absorption of moisture by the bean and to m[ustiness in the final product. When correctly fermented the mucilage comes off easily and the parchment does not stick to the hand after washing. The beans feel rough and gritty when squeezed by hand.

The robusta coffee has more of sticky mucilage. Fermentation will not be complete even after 72 hours. Quite often the mucilage breakdown is not complete even after a very long period. Thus we resort to alkali treatment or frictional removal of the mucilage.

When the mucilage breakdown is complete clean water is let in and the parchment is washed pebble-clean with 3 to 4 changes of water.

Treatment with alkali. The removal of mucilage by treating with alkali takes about one hour for arabica and one and a half to two hours for robusta. The pulped beans are drained off excess water and furrowed with gorumanes (wooden ladle with long handle). A 10 % solution of caustic soda is evenly applied to the furrows using a rose can. About one kg of sodium hydroxide dissolved in 10 litres of water is sufficient to treat 25 to 30 forlits of wet parchment . The parchment is agitated thoroughly with gorumanes as to make the alkali come into contact with the parchment and is trampled for about half an hour. When the parchment is no longer slimy, and rattles, clean water is let in and the parchment washed clean with 3 or 4 changes of water.

Removal of mucilage by friction. There are pulpers such as ‘Raoeng’ and ‘Aqua Pulpa’ which pulp and demucilage the beans in one operation. A number of naked and bruised beans may occur in the parchment. It is thus necessary to adjust the machines to obtain uniform pulping and demucilaging. The sorting of fruits for uniform feeding by a siphon arrangement may also rectify this to a cosiderable extent. these machines are also often used for demucilaging after removing the fruit skins in the traditional pulpers.

UNDERWATER SOAKING. Wherever water supply is abundant and additional vats are available, the parchment is soaked for 12 hours and then given a final wash. This improves the quality both in appearance and in the cup.

DRYING the next stage in processing consists of drying the parchment in the sun until the moisture content is sufficiently reduced to permit the storage of beans till they are despatched to curing works.

When coffee is being dried it is necessary that all naked beans , pulper-nipped and bruised beans are sorted out and despatched to curing works seperately.

The coffee is then bagged into clean new gunnies. The coffee of different lots should be bagged seperately. New gunnies should always be turned inside out and well aerated before use , as otherwise coffee will absorb natural oils and off odours from the bag and give rise to an ‘acrid’ cup.

PREPARATION OF CHERRY

For preparing chery the fruits should be spread evenly with a thickness of about 8 cm on clean drying ground. it is desirable that drying is carried out on tiled or concrete floors. Coffee should be stirred and ridged at least once every hour. As in the case of parchment the coffee may be heaped up and covered every day in the evening and spread again the next morning. The cherry is dry when a fistful of the drying cherry rattles when shaken . the cherry should be dried completely at the end of 12 to 15 days in bright weather. Each lot is bagged seperately in new gunnies.

Stripping. After harvesting, some green fruits of coffee may still be clinging to the plants. They are stripped off completely, dried and sent to the curing works seperately. This coffee must be marked and bagged distinctly as strippings.

STORAGE AND DISPATCH

Stores should be well ventilated and dry. The bags containing dried parchment or cherry should be stored on raised platforms to ensure circulation of air beneath the bags. The parchment and cherry coffee should not be stored together. Other materials like fertilizer etc should not be stored in the same room.

The bagged coffee should be dispatched to the curing works at the earliest possible. The bags must bear labels in respect of their grades, lot numbers and other details with instructions to cure them seperately.

All gleanings and floats should be packed and sent seperately for curing.