Tea cultivation in the Indian Himalayan region

 ABSTRACT

This paper deals in the genesis of tea cultivation in India, methods of breeding, environment for growing tea, its huge impact on the economy of India and the health values of tea. At one point of time, India was the world leader both in tea production as well as in export but gradually lost its position to other tea growing countries in recent years. It is now important to turn around and to get back its lost glory in the world Tea Market.

Key words: Tea cultivation, Bio-organic farming, Economic scenario, Pharmacology

INTRODUCTION

Tea plant, Camellia sinensis (L.) Kuntze (Theaceae), has been originated in China. Emperor Shen Nung of China discovered tea in 2737 BC while travelling through a hilly terrain with his caravan. He fell sick and wanted to take rest in a hill forest. He was shivering with cold due to fever and asked for warm water. Hot-water was prepared in a make shift oven where a tea leaf dropped from the over-head tree-branches in the pan water. When Shen Nung drank that water (tea decoction), he felt relaxed and his body ache was relieved. That was the first occasion when the health value of tea was discovered. Thereafter, tea travelled a long way to climb up to the position as the mostly consumed drink in the world after water, the Adam’s wine. Tea cultivation in India started in the early nineteenth century. Slowly but steadily tea became an important commercial commodity and a significant foreign money

788 Plant Diversity in the Himalaya Hotspot Region

earner. Tea Research in India started in 1891. With the advent of Tea Research in India, the productivity and quality followed a steady upward graph and occupied a conspicuous status in the economy of the country (Barbora, 1994).

Tea cultivation is linked with many environmental and other agro-ecological problems including huge infestation by wide range of pests. But the scientists continuously explored the ways and means to ameliorate or reduce the problems evolving new technologies. Tocklai Tea Research Institute (TTRI) in Jorhat, Assam; UPASI Tea Research Foundation (UPASI TRF) in Tamil Nadu; Institute of Himalayan Bio-resource Technology (IHBT) of Palampur in Himachal Pradesh played laudable roles in the field of Tea research and development. Tea Board India under the Ministry of Commerce & Industries, Government of India is the apex body of tea which deals in the Tea Development, Tea Research and Tea Promotion in the country.

HISTORY OF TEA CULTIVATION IN THE HIMALAYAN REGION

In 1788 Sir Joseph Banks forwarded a recommendation to Warren Hastings, the then Governor General of British India to attempt tea cultivation in Bihar, Coochbehar and Rangpur. In 1823, Major Robert Bruce came to upper Assam to find out the feasibility for tea trading and visited Rangpur, the then capital of Assam but now in Bangladesh. Robert Bruce first met Maniram Dewan, who introduced him to a Singpho Chief who informed that indigenous tea plants are growing wild in the forests of Upper Assam and Singpho hills. The Singhpho Chief also informed him that they use a kind of drink made from young shoots of a plant called Finap, which was nothing but the Tea plant. He showed the plant to Robert Bruce. Singpho Chief presented seeds and young plants of Tea to C.A. Bruce, who was the brother of Robert Bruce. C.A. Bruce sent those seeds and plants to David Scott, the Commissioner of Assam in Gauhati (now Guwahati). David Scott planted those saplings and sowed the seeds in the compound of his residence in Gauhati. In 1825, Col. Surgeon, Neufville, Charlton, Bhola Nath Parbetta, Phukan and Maniram Dewan went to Singpho hills to see those tea plants. Maniram Dewan escorted the team to Tikok, Margherita, Tipong etc and discovered many clumps of indigenous tea plants in those jungles. At that time Governor General William Bentinck took interest in tea cultivation and formed a tea committee in January, 1834 with Dr. N. Wallich as the Secretary to explore the possibilities of setting up an experimental cultivation plot. G.J. Gordon was sent to China to procure tea seeds and to collect information on tea cultivation and also to outsource few Experts from China. C.A. Bruce was appointed as the Superintendent of the Governor for Tea Cultivation mechanism. C.A. Bruce explored the areas from Jaipur to Namrup along the hills and discovered many indigenous tea plants in the jungles. He manufactured tea from those indigenous plants and sent

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first consignment of tea to England in 1838. The first sample of tea made from indigenous wild tea plants from Jaipur of Assam was already sent to Calcutta (now Kolkata) in 1836. It contained 95 chests from the Government Tea Manufacturing unit and thirty chests from Singpho Cjief’s Ningroola Plantation area. Singpho tribe were manufacturing tea and used as beverage from time immemorial. In 1839, the Government started a tea garden near Chabua, Dibrugarh with china variety tea and China and Assam varieties at Jaipur. Since then a hybrid variety of tea with China and Assam came into being. In 1839 an English man Hannay started a tea garden at Chabua. In 1840 Government owned tea garden was sold to Assam Company. By 1852, tea plantation expanded to Surma valley and in 1853-’54, tea plantation was started in Darjeeling in commercial scale. Shortly after that, tea plantation started in Chittagong (now in Bangladesh), Chhota Nagpur and Dooars of Jalpaiguri district. Tea nurseries were raised in Botanical garden, Calcutta; Saikhowa near Sadiya in Upper Assam, Dehradun and at Kumaon simultaneously (Anonymous, 1988).

TEA IN NORTH BENGAL

Tea plantation in Darjeeling Hills began in 1840 – 1841. Dr. Campbell, the first Collector of Darjeeling and the founder of Darjeeling town pioneered the effort that led to the opening of the hill’s first tea garden in 1854 or 1856. In 1841, Dr. Campbell brought tea seeds from Kumaon and planted near his residence in Darjeeling. In 1842, Dr. J.D. Hooker sowed few seeds at Lebong, near Darjeeling. In Darjeeling sub-division, the first tea garden was Tukvar Tea Estate and in Kurseong sub-division Makaibari Tea Estate was the first. Those gardens were started during 1843 to 1845. In 1860, the foothills of Darjeeling, which is better known as Terai opened up for tea cultivation. In Terai region Chumta was the first tea garden. First tea garden in Dooars, which is the foothills of Jalpaiguri district came up in 1874. In Dooars the first tea garden was started by Dr. Brongham in 1874 in Gazaldubi [= Gazaldoba] near Oodlabari of Jalpaiguri district. By the turn of the century, there were 170 tea gardens covering an area of 20,948 hectares. Before tea was monopolized in Darjeeling hills and foothills, scattered groups of Lepchas, Bhutias, Bavas and Meches lived here practicing subsistence level agriculture and often leading a nomadic or semi-nomadic life. At that time Darjeeling hills were under the control of Sikkim and the Dooars plains were under the control of Bhutanese kingdom. In less than hundred years both were added to British Bengal (Anonymous, 1998).

CONDITIONS REQUIRED FOR GROWING TEA

The wide diversity of habitat structure and prevailing wide range of environmental conditions provided home to innumerable species of plants, animals and microbes. Within this, some areas have been recognized as suitable for growing tea plants

790 Plant Diversity in the Himalaya Hotspot Region

nicely. However, ideal habitat conditions required for the cultivation of Tea in the Himalayan region has been presented in Table 1.

Table 1. Different habitat conditions required for growing tea plants.

Required aspects State of aspects

Locality Nearer to marketing place, transport and trading facility

Depth of soil Pervious up to 1.5 – 1.8 m

Physical properties of soil Deep and porous

Drainage Good drainage with sufficient out fall

pH of soil 4.5 to 5.5

Ambient temperature 20 – 30° C (maximum 35° C )

Leaf temperature Min 21° C (maximum 39° C)

Soil temperature Not less than 20° C; Optimum 25° C

Day length Not less than 11 hours 15 minutes

Rainfall 1000 – 1400 mm of annual rainfall; 100 – 150 mm per month on

 an average

Relative Humidity 80 – 90 %

GEOGRAPHICAL CONDITIONS FOR TEA PLANTATIONS IN HIMALAYAS

Tea growing lands in this area lie between 24º and 27 º N latitude and 88º and 95

º E longitudes. The tea area can be divided in several regions like Brahmaputra and Barak valleys of Assam; North Bengal plains of Dooars and Terai; Darjeeling hills; Arunachal Pradesh, Meghalaya, Nagaland, Mizoram, Sikkim, Kangra valley of Himachal Pradesh, Dehradun valley in Uttarakhand.

In Brahmaputra valley, the monthly average maximum temperature fluctuates between 22º and 28º C during the main cropping season from April to September. However, at times the mercury rises to 37º C. Minimum temperature is around 7º C. Soil in this region is ranges from alluvial to highly sandy. In some cases the soil is rich loam and exhibits a red colour. Rainfall varies between 2100 to 2900 mm per annum.

In Barak valley, tea is grown mostly on low altitude hills (maximum 150 m) having peats, which is very rich in organic content. Annual rainfall in this regions ranges between 3000 to 5000 mm but the temperature resembles Brahmaputra valley.

The Dooars and Terai region have an elevation between 80 to 300 m AMSL. A major part in Dooars comprises of soil which is old, red, well weathered, rich, loamy soil, deep and acidic. In Eastern Dooars, the soil is mostly sandy loam, rich in lime, Manganese and Phosphorus. Average annual rainfall is 3000 to 5000 mm.

In the hills of Darjeeling, the altitude varies between 600 to 2200 m AMSL. The mean maximum summer temperature generally does not exceed 25º C and the

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average minimum temperature remains around 8º C. Rainfall varies between 2500 to 5000 mm. Soil is mostly sedimentary rock and sandy. Places affected with snowfall or regular frosts are not suitable for Tea cultivation.

In Kangra valley of Himachal Pradesh and Dehradun valley of Uttarakhand average annual rainfall is to the tune of 2800 mm. In these areas, temperature regime and soil condition is almost like Darjeeling hills (Bora & Deka, 1999).

ORGANISED TEA RESEARCH IN INDIA

Research activities on tea in India are related to the development of improved cultivars and cultivation methods has been initiated in the 19th century itself. Following are the important steps in Tea research activities in the Indian Himalayan region:

• 1891: Indian Tea Association and the Agricultural & Horticultural Society of Bengal jointly started research in tea. Mr. M. Kelway Bamber was appointed for the purpose.

• 1893: Dr. George Watt played a great role in tea research. He was basically an Entomologist.

• 1904: First tea research centre in India was established at Heeleakah Tea Estate of Assam where Dr. Harold Mann was the Scientific Officer.

• 1911: This research centre was then shifted to Jorhat on the bank of the river Tocklai. The centre was named as Tocklai Experimental Station. This research centre is considered as the greatest and oldest tea research centre in the world.

• 1964: Tea Research Association was formed. Now, TRA is the main organization which looks after the researches on tea in the entire North East India.

TAXONOMIC VARIETIES OF TEA

The scientific name of tea plant is Camellia sinensis (L.) Kuntze under the family Theaceae of the order Theales. Linnaeus gave the name “Camellia” in the honour of Joseph Kamel, a Maravian Jesuit who collected tea plants in the Philippines and sent to Ray & Petiver between the years 1683 to 1700. Another school of thought believes that the genus Camellia was named after an Italian Priest Camelli who was said to have introduced Camellia japonica L., an ornamental plant of Japan to Europe in 1739. Linnaeus named tea plant as Thea sinensis in 1753. Later on in 1887, Carl Ernst Otto Kuntze transferred the species epithet and produced the recombined name Camellia sinensis. Its important synonyms include Camellia theifera Griff. and Thea chinensis Seem.. But, in 1895, Engler and Prantle merged the genus Thea with Camellia. (Anonymous 1988; www.theplantlist.org).

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Mainly, there are three varieties of tea:

1. China variety [Camellia sinensis (L.) Kuntze var. sinensis]

In normal condition it is a small tree but on pruning shows distinct multi-stemming character, i.e. many branches emerge directly from the soil level. Leaves of China variety are very small and very high in Volatile Flavor Constituents (VFC) which imparts the ‘Muscatel Flavor’. Flavor Index is the ratio of VFC II and VFC I. In VFC IIs, Geraniol is the main component which emits a rosy flavor. Apart from geraniol, it contains Linalool and its oxides. The leaves have orthotropic (erect) growth habit. Length of lamina varies from 1.5 to 14 cm and width 1 to 2.5 cm. The China variety is favored for its natural flavor.

2. Assam variety [Camellia sinensis var. assamica (J.W. Mast.) Kitam.]

This is a much taller tree than the China variety and produces distinct trunk on pruning. Leaves are bigger than that of China variety with size 8 – 20 x 3 – 8 cm. The VFC content in Assam variety is much less than China variety. Assam variety is known for its dark cup character with high concentration of polyphenols.

3. Cambod variety [Camellia sinensis var. lasiocalyx (Watt) A.P. Das & C. Ghosh; synonyms: Thea assamica var. lasiocalyx Watt; Camellia assamica subsp. lasiocalyx (Planch. ex Watt) Wight]

The nomenclature of this China-Assamica hybrid variety is confusing. In tea related literature it is referred as Camellia assamica subsp. lasiocalyx (Planch. ex Watt) Wight. But, C. assamica itself is now a synonym of C. sinensis. Very recently Das & Ghosh (2016) looked after this problem and recombined it as a variety of C. sinensis.

This plant has the features like Assam variety but has broadly elliptic (boat shaped) leaves with not too distinct marginal veins, often with pink anthocyanin pigmentation on the base of petiole particularly when young. Leaves are having orthotropic growth habit and are pale green.

IMPORTANT TEA CLONES OF DARJEELING HILLS

After the introduction of basic varieties of tea in different parts of the Himalayas, mainly in North Bengal and Assam, with the passage of time some variant individual bushes were identified and were cloned for cultivation. Many such cloned bushes found superior and were adopted for large scale cultivation. Table 2 enumerates some such important clones recognized from Darjeeling Hills region.

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Table 2. Important Tea clones recognized from Darjeeling Hills region

Name of the Clone Place of origin Year of Flavor Index Yield & quality

  Release (standard: status

   100)

AV2 Ambari TE 1973 134 Standard clone

Phoobsering 312 Phoobsering TE 1973 141 Standard clone

Phoobsering 1404 Phoobsering TE 1985 88 Standard clone

Phoobsering 1258 Phoobsering TE 1987 100 Standard clone

Tukdah 78 Tukdah TE 1978 121 Standard clone

Tukdah 145 Tukdah TE 1978 110 Standard clone

Tukdah 246 Tukdah TE 1973 138 Standard clone

Tukdah 135 Tukdah TE 1978 104 Standard clone

Tukdah 383 Tukdah TE 1980 147 Standard clone

Tukdah 253 Tukdah TE 1978 76 Yield clone

Bannockburn 157 Bannockburn TE 1978 131 Quality clone

Bannockburn 777 Bannockburn TE 1973 86 Quality clone

Bannockburn 688 Bannockburn TE 1975 128 Yield clone

Balasun 9/3/76 Balasun TE 1989 84 Standard clone

Balasun 1A/76 Balasun TE 1989 96 Standard clone

Badamtam15/263 Badamtam TE 1989 88 Yield clone

Rungli Rungliot 4/5 Rungli Runliot TE 1975 97 Yield clone

Rungli Rungliot Rungli Runliot TE 1984 89 Standard clone

17/144

Thurbo 3 Thurbo TE 1989 96 Standard clone

Thurbo 9 Thurbo TE 1989 96 Standard clone

Happy Valley 39 Happy Valley TE 1897 108 Yield clone

Clonal Proving 1 Ging TE 1984 98 Yield clone

Kopati 1/1 Not known 1985 129 Quality clone

Sikkim 1 Sikkim 1989 104 Standard clone

Teesta Valley 1 Teesta Valley TE 1987 117 Standard clone

[Standard clone: Above average yield and quality with a yield potential of 3000 to 3500 kilogram made tea per hectare per year (MTKHY)

Quality clone: High quality but average yield with a yield potential 2500 to 2800 kilogram made tea per hectare per year (MTKHY)

Yield clone: Average quality but high yielding with a yield potential of about 4000

kilogram made tea per hectare per year (MTKHY)] (Source: Barman, 2013).

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IMPORTANT TOCKLAI VEGETATIVE CLONES FOR THE SUB-HIMALAYAN REGION

In the similar manner, large number of good tea clones have been recognized at Toklai Experimental Station. Some such Toklai Variety (TV) clones has been presented in Table 3.

Table 3. Clones developed at Toklai

Name of Place of origin Year of Drought Manufacturing Yield & quality

Clone Release Tolerance preference status

TV 1 Cinnamora TE 1949 Tolerant CTC* Standard clone

TV 2 Betjan TE 1949 Susceptible Orthodox** Standard clone

TV 3 Rajgarh TE 1949 Susceptible Orthodox Standard clone

TV 4 Betjan TE 1959 Susceptible Orthodox Standard clone

TV 5 Betjan TE 1959 Susceptible Orthodox Standard clone

TV 6 Betjan TE 1959 Susceptible Orthodox Standard clone

TV 7 TTRI*** 1959 Susceptible Orthodox Standard clone

TV 8 Betjan TE 1959 Susceptible Orthodox & CTC Standard clone

TV 9 Upper Burma 1959 Tolerant CTC Standard clone

TV 10 Tingamaria TE 1963 Moderate- CTC Standard clone

   ly Tolerant

TV 11 Tingamaria TE 1963 Tolerant Orthodox Standard clone

TV 12 Betjan TE 1963 Tolerant Orthodox Standard clone

TV 13 Dullang TE 1965 Tolerant Orthodox Standard clone

TV 14 TTRI 1967 Tolerant CTC Standard clone

TV 15 Khowang TE 1967 Susceptible Orthodox

TV 16 TTRI 1968 Tolerant CTC Standard clone

TV 17 TTRI 1968 Tolerant CTC Standard clone

TV 18 TTRI 1970 Tolerant CTC Standard clone

TV 19 TTRI 1973 Tolerant CTC Standard clone

TV 20 Deopather TE 1974 Tolerant CTC Standard clone

TV 21 Manipur TE 1976 Tolerant CTC Quality clone

TV 22 TTRI 1976 Tolerant CTC Yield clone

TV 23 TTRI 1976 Tolerant CTC Yield clone

TV 24 Aizawal 1979 Tolerant CTC Standard clone

TV 25 Ayapather TE 1982 Tolerant CTC Yield clone

TV 26 Ayapather TE 1982 Tolerant CTC Yield clone

TV 27 TTRI 1985 Tolerant CTC Standard clone

TV 28 TTRI 1985 Tolerant CTC Standard clone

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TV 29 TTRI 1990 Moderate- CTC Yield clone

   ly Tolerant

TV 30 TTRI 1993 Moderate- CTC Yield clone

   ly Tolerant

TV 31 TTRI 2006 Moderate- CTC Yield clone

   ly Tolerant

[*CTC: Crushing Tearing Curling Manufacturing Method in which leaf is cut.

** Orthodox: A Manufacturing Method in which leaf is not cut, only twisted.

***TTRI: Tocklai Tea Research Institute, Jorhat, Assam] (Source: Barman, 2012)

PRUNING METHODS OF TEA IN THE HIMALAYAN REGION

Pruning is one of the most important agronomic practices in Tea cultivation. Unless plants are pruned, they will not form bushes and will not produce thousands of branches with growing tips. In the Himalayan region following types of pruning is done:

I. Young Tea Pruning

0 YEAR (the year of planting): In this year training of newly planted tea saplings is done. Training is a method to promote lateral growth. One of the following methods is implemented about three months after planting, depending on the status, number of branches and health of the plants:

Very weak plants: Left as such and allowed to grow.

Single stemmer with majority of the leaves above 20 cm from the ground level: In this case, “DE BUDDING” is carried out. In this method all the axillary buds and apical buds above 20 cm from the ground level are pinched off with the help of finger nails or forceps.

Single stemmer with plenty of leaves within 20 cm from the ground level: In this case ‘HAND LUNG PRUNING’ or ‘THUMB BREAK’ is done with the help of fingers. The leader stem is bent towards the Southern side at a height between 15 and 25 cm from the ground level. In this process, the vascular tissues (xylem and phloem) are disturbed in such a way that the free flow of solutes / translocation of solutes above the afore-stated height is restricted, as a result lateral shoots develop from the lower nodes.

Plant with two or more branches: In this case the upright, central leader stem is removed with the help of a 7.5 cm bladed pruning knife. The method is known as ‘DE CENTERING’ or ‘CENTRE OUT’. No particular height can be assigned for this pruning because the middle stem should be cut at the junction at whatever height it is situated.

796 Plant Diversity in the Himalaya Hotspot Region

Plants having thick stem and the first lateral situated at a height more than 20 cm: In this case ‘PARTIAL RING BARKING’ is done at a height of 15 cm.

There are few more methods for Training of Young tea like ‘PEGGING’ (the branches are bent and pegged with a hook), ‘HORMONAL OR CHEMICAL PRUNING’ (growth suppressants like Cycocel, Paclobutrazol, Ethepon, Oxyfluorfen are sprayed on the decentred plants), but these methods are not popular.

+ 1 YEAR: In this year RCO (Re-center Out) is conducted. The left over central leader stems are cut, the crisscross branches which tends to enter the center and thin whippy branches are removed. The bush is skiffed at a height of 55 cm from the ground level.

+ 2 YEAR: The bush is pruned at 35 cm from the ground level. This is known as ‘FIRST FRAME FORMING PRUNING (FFP)’. At the point of pruning the thickness of the stems should preferably be pencil thick. The cut marks should be as follows:

a) Each cut mark should be round and small

b) The marks should not be oblique

c) The marks should not be like a tooth brush

d) All the marks should face the centre

e) All the marks should be situated at the same height from the ground level

f) All the knots around the specified pruning height; to remove the knot, the pruning height may be adjusted according to necessity.

Following should be removed during the process by the process of ‘KNIFE CLEANING OUT (KCO)’ by using a 7.5 cm long bladed pruning knife with hook type apical portion.

i) All the crisscross branches

ii) All thin whippy branches

iii) One of the two branches at the close proximity. The weaker of the two branches should be removed

iv) All the hanging branches (Pankha daali).

Minimum number of branches should be removed during the First FFP. The bush should not become hollow centered.

A pruning stick, yellow painted with black mark at 55 cm level should be used. This stick should be kept in the middle portion of the bush. One such standard stick should be used in each and every bush.

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BREATHER: A breather should be kept in the middle and this should be removed when sprouting starts from the pruned branches.

+3 YEAR: At this age no severe pruning is done. The bushes are given a Levelling of Skiff (LOS) or a top skiff

+ 4 YEAR: In this year, the bushes are pruned at about 40 cm from the ground level. This is known as ‘FINAL FRAME FORMING PRUNING (FFP)’. In this year also Knife Cleaning out (KCO) is done.

II. Mature Tea Pruning

Height of pruning:

• Collar Prune (CP): 10 cm from Ground level (GL)

• Heavy Prune / Rejuvenation Prune (RP): 40 – 45 cm in plains and 15 – 37 cm in hills from GL

• Medium Prune (MP): 50 – 65 cm in plains and 35 – 50 cm in hills from GL

• Height Reduction Pruning (HRP): 70 – 75 cm from GL; in plains only

• Light prune (LP): 4 – 5 cm above the last pruning mark

• Deep Skiff (DS): 10 – 13 cm above last LP mark

• Medium skiff (MS): Just below majority of crow’s feet

• Light skiff ( LS): At current years tipping level

• Levelling – off – skiff (LOS): 5 cm above current year’s tipping level.

Pruning cycles

• Gardens in the plains: 3-4 years’ cycle : LP-UP-UP ; LP-DS-UP ; LP-UP-DS ; LP-MS-DS ; LP-UP-DS / MS –UP

• Gardens in the hills: 4 – 5 years’ cycle : LP-UP-DS-LS-UP ; LP-UP-UP-DS / MS –UP

TEA PESTS IN THE HIMALAYAN REGION

Tea is subjected to the infestation of various types of pests which includes sucking insects, leaf eating insects, mites, fungus, algae, flowering plants, etc. It has been estimated that, on an average, about 5 to 10 % of the crop is lost due to pest attack (Sivepalan, 1999). It is assessed that 13 % crop loss in North-Eastern tea growing areas is due to pest infestation. According to Banerjee (1976) crop loss in North-East India due to pest attack ranges between 6 and 14 %. Muraleedharan (2004) reported 15 to 20 % crop loss for this. Again, Sinha (2010) reported that crop loss due to pest infestation can be as high as 15 – 25 %.

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Major sucking pests:

Major sucking pests affecting tea plantations in the Himalayan region has been presented in Table 4.

Table 4. Common sucking insects in Himalayan Tea Gardens

Common name Scientific name

Tea Mosquito bug Helopeltis theivora

Tea Thrips Scirtothrips dorsalis

Tea jassids Empoasca flavescens

Aphis / Aphid Toxoptera aurantii

Major leaf eating pests in the Himalayan region

Large number of insects those are feeding on tea-leaves cause huge loss in production and quality of made tea. Some major leaf-nesting insects have been recorded in Table 5.

Table 5. Insects nesting on tea leaves in the Himalayan region

Common name Scientific name

Looper Caterpillar Biston suppressaria, Hyposidra talaca, Hyposidra infixaria, Ectropis sp.

 , Ascotis sp, Cleora sp.

Red slug caterpillar Eterusia magnifica

Bunch Caterpillar Andraca bipunctata

Major mites in the Himalayan region

Large number of mites is also living in Tea Gardens and they greatly affect the quality of made tea (Table 6).

Table 6. Common mites affect plants in Himalayan Tea Garden

Common name Scientific name

Red spider mites Oligonychus coffeae

Scarlet mite Brevipalpus phoenicis

Pink mite Acaphylla theae

Purple mite Calacarus carinatus

DISEASES OF TEA

There are many species of fungus and algae which infects tea plants leading to the proliferation of diseases, which, in turn, greatly affect the quality and yield of finished tea. Almost all parts of a tea plant can suffer from diseases. Some common pathogens causing diseases in tea plants of Himalayan region are presented in Table 7.

Primary diseases in the Himalayan region

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Primary diseases of common in the Himalayas are presented in Table 7 and the photographs of some diseases have been provided in Plate I.

Table 7. List of pathogenic organisms causing diseases in different parts of tea plants

Name of disease Causal Organism

 Root diseases

Brown root Rot Fomes lamaoensis

Charcoal Stump Rot Ustulina zonata

Red Root Rot Poria hypobrunnea

Black Root Rot Rosellinia arcuata

Tarry root rot Hypoxylon asarcodes

Purple root rot Helicobasidium compactum

 Stem diseases

Nectria Nectria cinnabarina

Poria Poria hypobrunnea

 Leaf diseases

Black Rot Coticium invisum & Corticium theae

Blister Blight Exobasidium vexans

Secondary diseases in the Himalayan region

Secondary root diseases have pre-disposing factors for causing of the disease viz. water logging, heavy drought, lightening, potash deficiency, etc. Sometimes secondary diseases cause great loss to the plantations including large scale death of tea plants. Violet root-rot caused by Sphaerostilbe repens and Thorny blight caused by Aglaospora sp. are the common secondary diseases of this region.

Like roots, stems of tea plants may also suffer from secondary diseases and two such common diseases are Jew’s ear fungus caused by Auricularia auricular and Thorny blight.

VASCULAR WEEDS

A huge proportion of tea is lost due to weed infestation. Weeds compete with tea plants for water, air and light. Against the background of extremely rich Himalayan biodiversity the weed flora of Tea Gardens of this region is also extremely diverse which is highly represented by three major groups of vascular plants, namely pteridophytes, dicotyledons and monocotyledons (Ghosh et al., 2004; Ghosh, 2006; Ghosh & Das, 2009). Weeds are not the strangers in a region and are entering in the crop fields mainly from the surrounding vegetation. Sometimes they enter through seeds and manures also. In Darjeeling Hills region many endangered and endemic plants are

800 Plant Diversity in the Himalaya Hotspot Region

    B C

 A

D E F G H I

J K L M

N O

        P Q

R S T U V W

X Y Z Za Zb Zc

PLATE-I. Tea: A. Camellia sinensis var. sinensis; B. C. sinensis var. assamica; C. C. sinensis var. lasiocalyx; D. Brown Root Rot; E. Red Root Rot; F. Purple Root Rot; G. Charcoal Stump Rot; H. Violet Root Rot; I. Stem Red Rust; J. Black Rot of Leaves; K. Blister Blight; L. Brown Blight; M. Grey Blight; N. Cockchafer grub (Holotrichia impressa); O. Termites (Microceroternes sp); P. Tea Mosquito bug ( Helopeltis thievora); Q. Red borer (Zeuzera cofeae); R. Thrips (Scolothrips dorsalis); S. Green fly (Jassid) (Empoasca flavesens); T. Looper caterpillar (Buzura supressaria); U. Looper caterpillar (Hyposidra talaca); V. Looper caterpillar (Hyposidra infixaria); W. Purple mite (Calcarus carinatus); X. Looper caterpillar (Ectropis sp.); Y. Looper caterpillar (Ascotis sp.); Z. Looper caterpillar ( Cleora sp.); Za. Red spider mites (Olygonychus coffeae); Zb. Pink mite (Acaphylla theae); Zc. Scarlet mites (Brevipalpus phoenicis).

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also known to grow in Tea Gardens (Ghosh & Das, 2009). Though these plants are treated as ‘weeds’ while growing within the plantations, but many of those are quite useful for the human society (Ghosh & Das, 2011).

Major weeds in the tea plantations of Himalayan region: Following is a short list of such weeds (Ghosh, 2006; Kabir & Das, 2015).

DICOTYLEDONS: Abutilon indicum L. (Malvaceae), Acalypha indica L. (Euphorbiaceae), Achyranthes aspera L. (Amaranthaceae), Ageratum conyzoides L. (Asteraceae), Alternanthera sessilis (L.) R.Br. ex DC., Amaranthus spinosus L. (Amaranthaceae), Argemone mexicana L. (Papaveraceae), Artemisia vulgaris L., Bidens biternata (Lour.) Merr. & Sherff (Asteraceae), Spermacoce articularis L.f. (Rubiaceae), Croton bonplandianus Bail. (Euphorbiaceae), Cuscuta reflexa Roxb. (Convolvulaceae), Drymaria cordata Willd. (Caryophyllaceae), Eupatorium odoratum L. (Asteraceae), Euphorbia hirta L. (Euphorbiaceae), Galinsoga parviflora Cav., Helichrysum indicum (L.) Grierson [=Gnaphalium indicum L.] (Asteraceae), Lantana camara L. (Verbenaceae), Leucas aspera (Willd,) Spreng. (Lamiaceae), Limnophila heterophylla Benth., Lindenbergia indica (L.) Kurz (Scrophulariaceae), Melastoma malabathricum L. (Melastomataceae), Mikania cordata (Burm.f.) B.L.Rob. (Asteraceae), Mimosa pudica L. (Leguminosae: Mimosoideae), Oldenlandia corymbosa (L.) Lam. (Rubiaceae), Phyllanthus fraternus G.L. Webster (Euphorbiaceae), Persicaria chinensis (L.) H. Gross, Persicaria hydropiper (L.) Delarbre (Polygonaceae), Scoparia dulcis L. (Plantaginaceae), Sida acuta Burm.f. (Malvaceae), Solanum nigrum L., Solanum torvum Sw. (Solanaceae), Sonchus arvensis L., Tridax procumbens L. (Asteraceae), Urena lobata L. (Malvaceae).

MONOCOTYLEDONS: Axonopus compressus (Sw.) Beauv. (Poaceae), Commelina benghalensis L. (Commelinaceae), Cynodon dactylon (L.) Pers. (Poaceae), Cyperus rotundus L. (Cyperaceae), Eleusine indica (L.) Gaertn., Imperata cylindrica (L.) P. Beauv., Paspalum scrobiculatum L., Setaria glauca (L.) P. Beauv. (Poaceae), etc.

PLANT PROTECTION CODE FOR TEA

Plant Protection code (August 2017, Ver. 9.0) Policy on usage of Plant Protection Formulations in Tea Plantations of India issued by Tea Board India provided lists of different formulations those are also applicable for the Himalayan Tea Gardens.

List of approved Plant Protection Formulations for use

in Tea plantations

Type of Sl. Name of PPFs

PPFs No.

 1 Cyflumetofen 20 SC

Acaricides 2 Dicofol 18.5 EC

 3 Ethion 50 EC

 4 Fenazaquin 10 EC

 5 Fenpyroximate 5 EC/SC

 6 Hexythiazox 5.45 EC

 7 Propargite 57 EC

 8 Sulphur 80 WP

 9 Sulphur 40 WP

 10 Sulphur 52 SC

 11 Spiromesifen 22.9

 12 Etoxazole 10 SC

 13 Flufenzine 20 SC

Insecticides 14 Azadirachtin 1 EC

 15 Azadirachtin 5 EC

 16 Bifenthrin 8 SC

 17 Clothianidin 50 WDG

 18 Deltamethrin 2.8 EC

 19 Deltamethrin 11 EC

 20 Emamectin Benzoate 5 SG

 21 Fenpropathrin 30 EC

 22 Flubendiamide 20 WG

 23 Phosalone 35 EC

 24 Quinalphos 25 EC

 25 Quinalphos 20 AF

 26 Thiacloprid 21.7 SC

 27 Thiamethoxam 25 WG

 28 Thiamenthoxam 12.6% + L-Cyhalothrin 9.5%

Bio-pesticides 29 Beauveria bassiana 2.5%WP (Cfu count 2X10 gm)

Fungicides 30 Carbendazim 12% + Mancozeb 63% WP

 31 Hexaconazole 4% + Zineb 68% WP

 32 Hexaconazole 5 EC

 33 Propiconazole 25 EC

 34 Copper Oxychloride

Herbicides 35 Glyphosate 41 SL

 36 Glyphosate 71 SG

 37 Glufosinate Amonium13.5 SL

 38 Glyphosate Ammonium Salt 5 SL

 39 Oxyfluorfen 23.5 EC

 34 Paraquat Dichloride 24 WSC

 41 Oxyfluorfen 2.5% + Isopropyl amine salt of Glyphosate

  41% w/w SC

 42 Carfentrazone Ethyl 0.43% + Glyphosate 30.82% EW

BIO-ORGANIC FARMING IN THE HIMALAYAN REGION

Synthetic pesticides and inorganic fertilizers induce environmental pollution and health hazards. Although through various discussions, publications it has been endeavored to generate awareness among people about the menace of synthetic chemicals, the level of reduction in chemical use is still insignificant. After the publication of the book ‘Silent Spring’ by Rachel Carson (1962), there has been a growing consciousness among the planting community to reduce the use of conventional synthetic chemical pesticides and keep the residue level under control. At one point of time, it was almost impossible to replace conventional pesticides and fertilizers because alternatives were hardly available. But, today, host of alternatives are available in the market. This revolutionary change in attitude of the manufacturing companies has ushered in a new era in easy conversion of conventional tea gardens to bio-organic ones, without any/ much set back in productivity of tea.

Tea plantations in Himalayan region also adopted the principles of Bio-Organic farming to a considerable proportion to reduce the menace of chemical pesticides. In many tea gardens of this region, Integrated Pest Management is followed:

Plant Resistance (Varietal Control): The resistance and susceptibility of a tea clone or seed stock in respect of any pest is taken into consideration. For example TV 23, Phoobshering 312 are susceptible to red spider mites; Teenali 17/1/54 is somewhat resistant to red spider mites. Hence in an area with such problem planters avoided growing of TV 23 and Phoobshering 312. Tocklai Vegetative 1 (TV 1) is susceptible to Tea mosquito bug, hence where Tea mosquito bug infestation is prevalent, planting of this cultivar is avoided. TV 9 is resistant to Violet root rot disease, hence for the waterlogged sections, planting of TV 9 is considered as a good clone.

Cultural Control: Most of the insects / mites need alternate hosts (mostly weeds) to complete life cycles. So, breeding of these pests can be controlled through the

Plant Diversity in the Himalaya Hotspot Region 803

management of those weeds inside the gardens and in the surrounding vegetation. For red spider mites, dust deposition on leaves serves as their breeding ground; hence in many tea gardens of this region, barrier hedge like Justicia adhatoda, Duranta erecta and Lantana camara are planted on the boundary to prevent the entry of dust. There are two categories of pests found in the tea gardens. One is positively thermo (thermophilic) and phototropic, such organisms (red spider mites, thrips etc.) increase population massively in congenial weather conditions. The other type is negatively photo- and thermo-tropic (Tea mosquito bug, Exobasidium vexans), so they will increase population where temperature is low and solar radiation is less. Hence, in case of the first type, adequate shade trees, which retain maximum foliage during dry period / drought are planted.

Biological Control: Microbial pesticides, both entomo- and phyto- pathogens are now used in the tea plantations of Himalayan region.

Common entomo-pathogens are Paecilomyces fumosoroseus, Paecilomyces lilacinus, Verticillium lecanii, Beauveria bassiana, Metarhizium anisopliae, etc.

And, common phyto-pathogens are Trichoderma viride, Pseudomonas fluorescence, Bacillus thuringiensis, etc.

Weed Extracts:

There are many weeds, the extracts of which help in controlling tea pests. Aqueous extracts of one species or in combination of few species are in use. Some such plants are presented in Table 8.

Table 8. List of local weeds used to control tea pests.

Scientific name Nepali name

Ageratum conyzoides Ilame

Artemisia vulgaris Titepati

Equisetum arvense Kurkure jhar

Eupatorium glandulosum Ban mara

Polygonum runcinatum Ratnaulo

Urtica dioica Shisnoo

Natural enemies of tea pests

Various predators, parasitoids and pathogens were found to be effective in controlling tea pests. Tea scientists have earmarked few predators/parasitoids/pathogens as natural enemies of tea pests, which are listed below in Table 9 (Kabir & Das, 2015).

804 Plant Diversity in the Himalaya Hotspot Region

Table 9. List of recognized enemies of tea pests those can be used in the plantations

Tea pests Natural enemy

[Insect/Mite/Disease/Nematode] [Predator/Parasitoids/Pathogen]

Black Scale Chilocorus circumdatus

Red Spider Mite Stethorus gilvifrons sp., Chrysoperla carnea, Scolothrips

 sexmaculatus, Paecilomyces fumosoroseus, Verticillium lecanii

Scarlet Mite Pronematus sp., Exothoris caudate, Cunaxa sp., Agisternus

 sp., Paecilomyces fumosoroseus, Verticillium leccanii

Pink Mite Amblyseius herbicolus, Paecilomyces fumosoroseus,

 Verticillium leccanii

Tea Mosquito Bug Melamphus sp., Hexanemus sp., Oxyopes javanus, Beauveria

 bassinana

Looper Caterpillar Sarcophaga sp., Apantales sp., Argyrophylax sp., Cotesia sp.,

 Bacillus thuringiensis

Red Slug Caterpillar Argyrophylax sp., Bacillus thuringiensis, Cotesia sp., Exorista

 sp.,

Eelworm Pasteuria neutrans

Leaf rollers Aphanogamus monitae, Ascogaster sp.,

Flush worm Sympiesis dolicogaster

Green fly Dyrid cephalosporium, Beauveria bassinana

Bunch Caterpillar Bacillus thuringiensis

Red rot Trichoderma harzianum, Ganoderma pseudoferreum

Black rot Trichoderma viride

BIO-DYNAMIC PREPARATION IN DARJEELING HILL

To avoid the synthetic fertilizers gardeners are now engaged in search of alternative methods of cultivation for better yield. Following this, now-a-days, various bio dynamic preparations are gaining ground in the tea gardens of Darjeeling