1. Developing Tea-based Crop Model in Wasteland of South Bengal for
Higher Income Generation
S. Palit
1
*, B. C. Ghosh
2
and K. K. Bhowmik
3
Introduction
In West Bengal, tea is grown under high rainfall on slopes of hills or high plateau in the
districts of Darjeeling and Jalpaiguri. In recent past, tea cultivation is expanded in marginal
and fallow lands in non-traditional areas. Tea as a perennial crop prefers to grow in deep
fertile well drained and acidic soil. Its cultivation is also attempted in southern part of West
Bengal at village Gopali of District West Midnapore and a new crop model was developed.
Methodology:
The lands were divided into series of plots of 50 m in length and 18 m in width. The soil
was deep ploughed, levelled and maintained a gentle slope (about 1 %) towards the drainage
channel at both sides of each plot. Drainage channels of 75 cm deep and 50 cm wide were
dug to prevent water logging. The field layout was done by staking and making pits of 45 cm
x 45 cm size. Each pit was filled up with soil and organic fertilizers. Planting was done at a
spacing of 100 cm between rows and 75 cm between plants. Six improved tea clones, TV1
(quality clone), TV9, TV22, TV 23, TV 25 and TV26 (productive clones), were planted in
different plots in 20 acres.
Shade is an integral component of tea ecosystem comprising tea plants, shade trees and green
manure crop to maintain optimum level of light intensity, temperature and relative humidity.
The shade tree species considered for plantation were Albezia lebbek (siris) and Leucaena
leueocephala (subabool) as woody tree, Psidium guajava (guava), Achras zapota (sapota)
and Emblica officinale (aonla) as fruit trees and Santalum album (sandal wood) were grown
in different plots. Besides, spices Piper nigrum (Black pepper) as climber and Zingiber
officinale (ginger), Curcuma longa (haldi) and Ananas comosus (pineapple) were grown as
border crops. The spacing of shade trees was 6 m x 6 m between rows and plants. The green
manure crop Sesbania sp (dhaincha) was sown after every 2 rows of tea to provide temporary
shade to tea to provide temporary shade to tea crop at initial growth stage as well as to enrich
soil fertility.
Fertilizer management:
An attempt was made to produce organic tea for which organic and natural sources of
fertilizers and pesticides were used. At planting vermicompost @ 4 kg and 40 g of
rock phosphate were applied in each pit as basal dose and were mixed thoroughly with
soil.
1
*corresponding author: Dr. Soumen Palit, Director, Eco Yes Technologies, Science and Technology
Entrepreneurs Park, IIT Kharagpur, West Bengal – 721 302, email:psoumen@gmail.com
2
Dr. B. C. Ghosh, Professor, Agricultural and Food Engineering Department, IIT, Kharagpur, West Bengal –
721 302, email:bcg@agfe.iitkgp.ernet.in
3
Dr. K. K. Bhowmik, Agriculture Officer, West Bengal Comprehensive Area Development Corporation,
email: kanchanbhowmik30@yahoo.com

2. In subsequent years, year –wise fertilizer schedule as per standard nutrient requirement of
crop on N equivalent basis was followed (Table -1). The vermicompost was applied as
topdressing in four splits in a year and mixed well in soil.
Table -1
Year Vermicompost
(tonnes/ ha)
N equivalent
(kg)
0
1+
2+
3+
4+
2.21
4.43
5.53
6.64
8.31
40
80
100
120
150
Year wise fertilizer schedule at young tea stage
Water management:
Tea is very sensitive to both excess and deficit soil moisture (stress) condition. During dry
season, irrigation was optimized through sprinkler irrigation system. This system is also
congenial to create microclimate for tea during hot dry months and also help to reduce
seasonal dormancy for sustained productivity. During rainy season, adequate drainage facility
was provided to remove excess water as tea is susceptible to waterlogged condition.
Debudding and pruning:
Debudding and pruning were done to maintain convenient height of tea bush to facilitate
plucking operation. It is aimed to check reproductive growth and simulation of vigorous
shoot system and maintaining sufficient volume of maintenance foliage to meet the
physiological needs of plants. During zero year, six weeks after plantation, all axillary buds
were removed leaving 9 inches from the ground level and also simultaneously shoot tips.
This practice encourages formation and growth of lateral shoots at base of plants.
Therefore, plants were allowed to grow up to 24 inches from the ground level and tipping of
shoot tips was done regularly. During 1 + year, out of developed branches, the leader was
removed leaving 11 inch from the ground level. This practice helps in uniform growth and
development of all the branches. At the end of 1 + year, the first frame forming pruning was
done by removing all branches leaving 14 inch from the ground level by using a pruning
knife.
Thereafter, new shoots were developed and were allowed to grow up to 10 inch from pruning
level and removal of young shoots was continued. During 2 +year, removal of young shoots
continued and bush height of 24 inch was maintained. The second and final frame forming
pruning was done at 3 + year by removal of all branches leaving 16 inch from ground level
and the new shoots were allowed to grow up to 10 inch from pruning level. In subsequent
years, light pruning, medium pruning, collar pruning, deep skiff, medium skiff, etc., were
practised in a time scale as per age of the bush.

3. Tipping and plucking:
Tipping is an essential operation aimed at formation of a level plucking surface and to induce
branching at a high level which produces more plucking point bushes. Plucking is most
important harvesting operation and intricately related to pruning and tipping. In plucking,
tender apical terminal buds and two expanded leaves are considered. A uniform plucking
table of about 50 cm diameter at 3 + year was developed by regular harvesting of two leaves
and a bud at 7 days interval.
Yield:
During 3 + year, yield assessment of made tea was done after processing of harvested leaf. A
total yield of 1,100 kg/ ha of made tea was achieved. Besides, 3.5 tonnes/ ha of guava and
175 kg/ ha of ginger, respectively were obtained. The fruiting in aonla, sapota and other crops
was recorded in subsequent years.
Nursery management:
For promoting tea cultivation in South Bengal, availability of planting material of good
quality clones at growing site is of vital importance. In this respect a seedling raising
technique and nursery management have been standardized. Vegetative propagation of tea
plants by means of stem cutting was attempted successfully and polythene sleeve nursery
technique was adopted for the same. For mother bush, a section of tea plantation area was
kept unpruned for each tea variety.
The stem cuttings were used as planting material. The cuttings of 3 -5 cm long and 3- 4 mm
in diameter were treated with IBA and planted in polythene sleeves of 7 inch in length and 4
inch in diameter which were filled up with soil of pH 4.8. The polythene sleeves were placed
under shade net (30 % infiltration of light). The seedlings were grown for a period of 8
months with a survival rate of 88 %.
Processing and quality assessment of tea:
After harvesting of tea leaves, tea was processed in steps, i. e. Withering –rolling –
fermentation-drying – grading. A miniature tea processing plant is established at IIT,
Kharagpur, by installing withering through rolling machine, fermentation floor, drier and
shorting machine.
Withering: In withering, initial moisture content of plucked leaves is brought down to 60 -
65%. Different physico-chemical changes in leaves increase cell membrane permeability,
initiation of polyphenol oxidase/ peroxidise activity, breakdown of chlorophylls and proteins,
degradation of carbohydrates, increase in caffeine and inorganic phosphate contents and
development of flavour volatiles. The leaves are spread uniformly on withering trough and air
blown for removal of moisture. The leaves are allowed to wither for a period of about 12 – 14
hours depending on initial moisture content in leaves.

4. Rolling: The leaves are macerated so that enzymes and their substrates got intimately mixed
up. The treatment also allows maximal availability of polyphenol oxidase during
fermentation as the enzyme is located in leaf epidermal cells and also produce flavour
compounds and degraded chlorophyll. During rolling, cell wall of leaves is ruptured and
thereby enabling the production of enzyme. The rolling process is continued for 45 minutes.
Fermentation: Fermentation involves oxidation of polyphenols by polyphenol oxidase. The
process involved spreading the macerated leaves uniformly in a layer of about 6 cm for a
period of about 2 hours on fermentation floor. During this process, polyphenols are oxidized
and then condensedto form theaflavins, thearubigins etc. The chlorophylls are degraded and
some of flavour components are produced from lipids, amino acids, carotenoids and
terpenoids. The outcome of fermentation process is development of colour strength and
quality of made tea.
Drying and grading: In drying, moisture content of rolled and fermented leaves is reduced
from 45 – 50 to 3- 4 % level in dried black tea. Drying is achieved by blowing hot air of 87°
to 93° C at the inlet and 56° C at the outlet. The drying process continues for 20 minutes.
During drying, inactivation of enzymes, loss of soluble solids, development/ loss of some
flavour components and conversion of chlorophyll to phaeophytin responsible for black
appearance of manufactured tea are important. Grading and sorting are done by grading
machine into different grades of made tea. The different grades are designated as broken
orange pekoe, broken pekoe, orange pekoe, fannings and dust based on relative proportion of
particle size.
Quality assessment: Polyphenols and caffeine are important indices for judgement of tea
quality. Among polyphenolic compound catechin content is estimated at 2.03 – 2.24 %in
different varieties tested. Caffeine is an important chemical present in made tea. Generally,
tea leaves contain about 4 %. Among test varieties, TV 26 had highest caffeine content. In
sensory evaluation the processed made tea by orthodox method is judged by tea taster to be
standard quality tea.
Conclusion:
The developed crop model by growing tea-horticulture-spices together in a multistoried
cropping system can be transferred and adapted in large tracts of marginal wasteland in acid
lateritic soil belt of South Bengal. There would be a gain in income and employment
generation for small and marginal group of farmers. Moreover production of organic tea and
other organic product from same cropping system received high market value. There is gain
in buildup of soil fertility by introduction of the crop model in marginal wasteland.