Energy requirement and cost economics in tea cultivation and processing in organic condition

RK Tiwari and Chauhan SK *

In India, tea has grown in an area of 51 million hectares producing 23 per cent of the global tea production. Since the introduction of tea in India, the industry has contributed immensely towards the socio-economic development north eastern states produce around 54% of India’s total tea production with Assam alone contributing 51% of India’s total and about one-sixth of the tea produced in the world.

India is the second largest producer of tea after China, so it is notable that tea industry presents a sizeable chunk in the economy of the country. Tea gardens and tea industries are largely scattered covering a major part of India. The crop is grown in the certain districts located in Assam, West Bengal, Kerala, Karnataka and Tamil Nadu and to some extent in Tripura, Uttar Pradesh and Himachal Pradesh.

In our country, total tea production is 840 million kg of annually. It is not a widely known fact, but 25 per cent of the total tea produced in West Bengal and Assam, and other north eastern states is produced by small growers. Their contribution to the total national tea production is 14 per cent.

There are three kinds of costs involved in tea production – namely, cultivation costs, manufacturing or processing costs, and social costs. Taking the cultivation costs alone into consideration, the tea cultivation is one of the most labour-intensive agricultural activities, and among the operations involved in tea production, plucking is one of the most labour-intensive.

Nearly 70 per cent of the labour in production is involved in the plucking operation, and approximately 40 per cent of the cost of production of tea goes into payment for the labour involved in plucking. The various factors influencing labour efficiency are yield of crop, plant density, age of the plant, plant variety, climatic conditions and topography. The efficiency also varies according to the physique and psychology of the workers. The cost of production for one kilogram of tea in north India is US$1.62, and in south india it is $ 1.48/kg.

There are 250 small tree growers in Sikkim. There is need of strategy for adequate resources, training for the majority of small growers to promote more cultivation of tea. One big hurdle is that organic certification by a recognised agency costs money and requires a mandatory waiting period of three years before the certificate is given.

Very few growers have the luxury of going through this tedious process. The lack of adequate resources, training and manpower has kept the majority of small growers bound to chemical agriculture. Many wish to break out of this vicious circle. Organic is viable because it reduces input costs, and improves the quality of green leaf and makes it more acceptable in foreign markets.

Temi Tea is an exceptional tea of quality grown in the Himalayan state of Sikkim. Temi Tea engaged in the business of production and marketing of Orthodox Black Tea since 1977. So far 500 acres of land has been covered by Tea plantation. The tea crop constitutes TRA certified clones, and Chinary seeds which are ideal for the manufacture of flavored teas.

The elevation of the garden is from 4800ft. to 1950.7 m above mean sea level. The tea crop grown in northeastern aspect. Annual production ranges to 100 tonnes. It has been certified 100% Organic by IMO, Control, a member group of IMO Switzerland since 2008. Temi Tea Estate is also HACCAP Certified as per ISO 2000 standard under Food Safety.

TABLE 1: Cost of cultivation of organic tea (Per kg of green tree leaves)

Item	Amount (in Rs)
Plucking	10.00
Carrying green leaf	4.00
Cleaning	4.00
Manuring	5.00
Weed control and cleaning	9.0
Total	32.00

The cost benefit ratio varied 1.69-2.60.

PROCESSING

Temi Tea manufacture is more of an art than science. The following are the five (5) steps to manufacture Temi Tea. 1. Withering 2. Rolling 3. Fermentation 4. Drying 5. Sorting & Packing.

Withering: Here the green leaves are kept on withering troughs and warm air is blown. The net result is that the leaves lose moisture to 65%.

Rolling: The rolling machine rolls and breaks the leaves by which the liquid content of leaves released and the fermentation and oxidation of the leaf begins.

Fermentation: During the fermentation process, the enzymes within the leaves are bound to the oxygen in the air. This process causes the leaves to blacken and this is what creates the typical flavor of black tea.

Drying: This is a process where the tea is dried, in dryers where, the character attained during fermentation are fixed.

Sorting: This process ensure bulk tea into four different grades.

Packing: Packing done for all gardes with different commercial names by trained skilled workers.

Table 2: Cost of processing organic tea

Item	Amount (Rs/kg)
Green leaf	60
Leaf collection expenses	3.0
Fuel (Firewood)	5.0
Electricity	6.0
Wages	10.0
Factory overheads	5.0
General overheads	3.0
Packing	2.5
Tax	0.50
Transport of made tea	3.0
Total cost of processing	98.00

The requirement of energy in tea processing industry is high with around 21% required as electrical energy and the remaining 79% supplied by conventional fuels. It has been reported that the total specific thermal energy consumption in India varies between 4.45 to 6.84 kWh/kg of made tea while specific electrical energy consumption in India between 0.4 to 0.7 kWh/kg of made tea. The plantation and transportation sector in an estate also consumes a large amount of energy in the form of petro-fuels.

Table 3.Thermal Energy consumption of different energy sources

Fuel	Amount of fuel consumption per kg. of made tea	Average energy consumed (MJ/kg. made tea)
Coal	1.125 kg	27.43
Leco	0.625 kg	18
Wood	2.0 kg	29.26
Natural Gas	0.625 Nm3	23.50
TD Oil Direct	0.300 kg	13.14
TD Oil Indirect	0.500 kg	21.96

Air is used in large quantities, under controlled conditions of temperature and humidity. Other raw materials are fuel, wood, Coal, Oil, gas. 1 tonne of dried tea requires approximately 4.5 tonnes green leaves, 450 kW electricity, 500 litres oil (or other fuel), depending on the process used, 250 man hours of work, 23 tea chests (or alternative packaging), 2000 tonnes of air.

Thus the cost of cultivation and processing of organic tea may be around Rs 130/kg as mentioned in Table 1 and 2. The thermal energy consumption by different energy sources are mentioned in table 3.

Need of Modernization for Tea Cultivation in Sikkim

Mechanization can be brought in at various degrees. Currently in India using of plucking shears give a helping hand during the rush season when crop output is high and there is a shortage of labour force. Hand operated plucking shears can increase the plucking efficiency from approximately 25 kg per worker per day to nearly 100 – 200, but while using plucking shears, in order not to compromise on the quality the coarse leaves which are harvested, along with the two leaf and bud should be removed manually.

Mechanization can be taken to a greater extent in future with improved shears, which are motorized and self-propelled. Motorized mechanical portable type shears can harvest 300 to 450 kg per day if it is operated by a single person and it can harvest 700 to 1500 kg leaves per day when operated by two people.

Self-propelled shears can harvest 2000 to 3000 kg of leaves per day thus increasing efficiency by several times. However as the degree of mechanization increases, the crop yield gets affected. Integrated schedules of hand plucking and shear harvesting can prevent reduction in crop yield and help in maintaining the crop cycles.

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* RK Tiwari and Chauhan SK wrote this article for The Sangai Express
RK Tiwari is Ex Research Engineer and Chauhan SK is Principal Investigator, AICRP on UAE, College of Agricultural Engineering and Technology, Ranipool, Sikkim E-mail: rk96tiwari(AT)gmail(DOT)com
This article was posted on November 18, 2016.

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