Nursery Vegetative propagation is carried out for clonal multiplication while biclonal seed stocks are propagated through seeds. The tea nursery should be located near a perennial water source. An over head ‘pandal’ is raised on which a coir mat with 6 mm2 mesh is spread so as to allow about 33% sunlight at midday into the nursery. Polythene sleeves with a dimension of 30×10 cm are used for filling up the sandy loam/clayey loam soils. The lower three-fourths of the sleeves may be filled with jungle top soil with appropriate proportions of sand to make it a sandy loam. The top one-fourth portion of the sleeve should be filled with the rooting medium. Both the soils should have a pH of 4.5 to 4.8 and EC below 0.05 dsm-1. One leaf and an internodal cutting with an axillary bud prepared from the ‘aperiodic shoots’ arising from pruned tea bush is planted in the nursery sleeve and covered with a polythene sheet of 400 guage. April / May and August / September are the most suitable months for planting in nursery. Single nodal cuttings and the grafted plants are prone to Pestalotia attack for the first to six weeks after planting. Contact fungicides like mancozeb at the rate of 30 g in 10 litres may be applied for protecting the rooting cuttings from Pestalotia attack. The plants are allowed to grow for 6-8 months in the nursery and then transferred to the open space for hardening. Hardened nursery plants are transplanted in the field.
Planting Should be carried out in the month of June where the areas receiving south-west monsoon and during August in the north east monsoon zones. About 13,000 plants are planted in one hectare following double hedge system of planting (spacing: 135 X 75 X 75 cm). One year old plants are planted in pits with a dimension of 30 X 45 cm. The selected plants for planting should have 14 to 16 healthy mature leaves and the root system should have reached the bottom end of the sleeves at the time of planting. The stem at the collar region should be about pencil thick and brown. Soil and water conservation measures must be adopted while new planting is taken up.
Training of Young Tea Three to four months after planting, apical dominance is arrested by cutting off the leader stem. This operation, called centering (or decentring), promotes the growth of axillary buds and lateral branches are formed. All the plants should be centered as low as possible leaving 8 – 10 healthy mature leaves. For further lateral branch formation, good spread and establishment of plucking surface the growing branches are trained by two stage tipping. First tipping is carried out at 35 cm followed by second tipping at 50 cm.
Formative pruning (branch formation pruning) is carried out at the end of five years after planting. The recommended pruning height for formative pruning is around 45 cm above ground level. At the time of formative pruning branches which are less than pencil size thick are removed.
Harvesting Young tea fields and the fields immediately after pruning is to be hand plucked irrespective of the season. Fields that had crossed more than 15 months from pruning can be harvested with the help of hand held shears. Shear harvesting increases the productivity of the workers. Hand held motorised harvesters have been evaluated and found useful to achieve high labour productivity. Both the one man and two men operated motorized harvesters are useful in tea fields planted on moderate and gentle slopes. The battery operated harvesters are also useful to increase the productivity of the women pluckers. During the drought season of December to March addition of a new tier of maintenance foliage is recommended by hand plucking to a mother leaf. Plucking interval for hand plucking may vary from 9 to 13 days in different seasons while it ranges from 15 to 18 days for shear harvesting.
Shade Grevillea Robusta Commonly called as Silver Oak is the recommended shade tree for tea in south India. The finely dissected leaves facilitate filtering of light and the deep root system does not compete with tea for nutrients. The tree is also suitable for pollarding and periodical lopping to regulate shade. Grevillea trees can also support the growth of pepper which is intercropped with tea. Grevillea plants are planted at 6.1 X 6.1 m spacing at the time of planting and thinned out at 12.2 X 6.1 m at the end of fifth year and latter on at 12.2 X 12.2 m at the end of ninth or tenth year. The trees are pollarded at a height of 7.6 m in estates located in high elevation and at 9.1 m in mid elevation regions. The trees are also annually lopped before the onset of the monsoon season. In south -west monsoon zones lopping should be carried out during April/May and the north-east monsoon season in August. Grevillea trees require a pH of around 6.0. therefore, application of 450 to 900 g dolomite lime is recommended to be applied in the planting pits depending upon the initial soil pH.
Pruning is carried out to keep the bushes continuously under vegetative stage. A pruning cycle of four years is recommended for the fields located in low and mid elevation areas and it is five years for the fields in high elevation. Generally a cut across pruning at 60-65 cm is followed depending upon the branch thickness. Formative of pruning is recommended at the end of five years after planting. Generally formative pruning is carried out at about 45 -50 cm from the ground level.
Tipping In ‘Assam’ jat fields, the tipping in material should be four leaves and a bud; Three tiers of leaves may be left above the pruning cut in fields pruned at 55 – 60 cm. Two tiers of leaves may be left above the pruning cut if the bushes were pruned at 60 – 75 cm. For “China” jat fields pruned at 55 – 75 cm, the tipping in material should be four leaves and a bud leaving two tiers of leaves above the pruning cut.
Mechanization Cultural operations such as pitting, pruning and harvesting are now being mechanized. We recommend the use of machines for increasing the productivity of the workers. The STIHL BT 120 C earth auger can increase the productivity of the worker nearly three times when compared to manual pitting. Pruning machines with spinning discs are nearly four times more efficient than the manual pruning with knives. One man and two men operated harvesters can increase the productivity four fold.
Weed Control The most common grass weeds in south Indian tea fields are Axonopus compressus (Sw.) P.Beauv (Carpet grass), Digitaria adscendens [HBK] Henr. (Crab grass), D.longiflora Pers (Finger grass), Panicum repens L.(Couch grass/Ginger grass), Paspalum conjugatum Berg(Buffalo grass). The common dicot weeds are, Ageratum conyzoides L. (Goat weed), Bidens biternata (Lour) Merr. & Shreff. (Spanish needle), Crassocephalum crepidioides (Benth) Moore. (Pile wort), Conyza ambigua DC, Mitracarpus verticillatus (Schum. & Thonn.)Vatke.
Backpack sprayers fitted with WFN 0.024, 0.040 and VLV-50 nozzles are used for spraying the recommended herbicides. Both the pre and post emergence herbicides are useful to control the weeds in tea fields. Pre emergence herbicides such as diuron and oxyfluorfen can be applied in young tea fields and in the pruned tea fields. The contact post emergence herbicide like paraquat is useful to control the weeds during the monsoon seasons. The translocated type of herbicides such as glyphosate and 2, 4-D can be sprayed during the pre and post monsoon seasons. For the control of mixed population of weeds with predominant infestation of broad leaved weeds glyphosate + 2, 4 -D + a non – ionic wetting agent at the rate of 1.75 litres + 1.40 kg + 0.50 litres in 450 litres of water / ha is recommended. For the control of grasses glyphosate + kaolin + a non – ionic wetting agent at the rate of 2.0 litres + 2.00 kg + 0.50 litres / ha is recommended. Alternately paraquat at the rate of 1.5 litres / ha can be sprayed for the control of soft weeds or the same herbicides at the rate of 2.25 litres /ha can be sprayed for the control of hardy weeds. Ammonium salt of glyphosate (Excel Mera 71) is also recommended at 30 g /10 L of water for weed control.