Tea Cultivation - Nursery management

Nursery management

Location

The nursery should preferably be located between low and mid elevations and also at a convenient place where constant supervision is possible. It would be helpful if the site is located near a perennial water source and is desirable if it is naturally protected from wind Seed production and propagation Selected plants are planted in 5 - 6 m apart in the seed orchards (known as ‘baries’ in the industry). The land of the seed bari should be flat or with a gentle slope with good drainage. The plant should be allowed to grow freely, apart from hygienic removal of dead branches with occasional thinning of branches to ensure entry of adequate light through canopy; trees must not interlock. A ground cover should be grown for the first few years and must be kept clear and free from weeds when production of seed starts. Seeds are borne mostly on the surface of canopy of the tree and collected on the ground.
Vegetative propagation Raising tea plants from single node cuttings has now been widely and successfully adopted economic method of vegetative propagation. The success of vegetative propagation depends upon the selection of plants that are above average yield and quality of processed tea.
Mother bushes The nucleus plot of mother bushes of desired clones from which cuttings are to be taken should be established at a convenient place as separate multiplication plots. A spacing of 100 cm triangular may be adopted for planting for Chinery clones. The plants should be protected from pests and diseases in order to obtain healthy cuttings for quicker growth in the nursery. In Darjeeling, mother bushes should be clean pruned between end of September to mid October every year. Annual pruning in mid or high elevations is not advisable. Cuttings with active axillary buds root quicker. 15 to 21 days prior to taking the cuttings, the terminal bud should be pinched off to initiate the axillary buds to sprout.
	Type and preparation of cuttings Cuttings should preferably be taken from the primaries with dormant apical buds after discarding two or three topmost leaves. In some clones, quite early the lateral shoots are thrown out from the lower portion of the primaries. In such cases, the unbranched portion of the primaries should be taken first and then the laterals when they mature after a few weeks. Multinodal cuttings may be advantageously utilized in certain clones in Darjeeling hills provided sufficient propagation material is available. Green, semi-hard wood with one leaf and an internode is taken from the stem with a sharp knife without injuring the bark or causing jagged cut as shown in picture.
Soil of cutting nurseries Soil has a critical influence on rooting of the cuttings. Rooting soil should be a sandy loam, porous and friable with a pH ranging from 4.5 to 4.8 though a pH upto 5.5 is not entirely hermful. High pH soil can be acidified using sulphur or aluminium sulphate or ferrous sulphate.
	Preparation of rooting beds and sleeves As soon as the beds are prepared or sleeves filled up, provision of shade should be made. If erection of shade immediately not possible then the rooting beds/sleeves should be covered with leafy mulch to facilitate protection of soil from direct sun and rain. It also helps to keep down weed growth. Beds can be of 1 m width and any length depending upon availability of the area and elevate them about 15 cm. The soil of the beds should be compacted slightly by using a light roller or back of a hoe. Usually, it takes 6 - 8 weeks for the soil to be ready for planting. An effective open drain should be made for easy run-off of surface water. In between beds, 50 - 60 cm deep drains may be provided which should be connected with an outlet drain.
	Polythene sleeves of the size 15 - 18 cm lay flat, 25 - 30 cm lengths and 150 gauge (300 sleeves in 1 kg) may be used in the nursery. The soil before filling the sleeves (may be passed through a sieve of mesh No. 4 to remove the undecomposed organic matter and pebbles. The sleeves should be filled with the minimum of raming, 8 - 10 weeks before cuttings are planted. The filled sleeves should be put together within frames of about 20 cm high made of iron wire or bamboo. This fence surrounds each bed for holding the sleeves upright.
Planting of cuttings The nursery beds or / and polythene sleeves ready for planting cuttings should be watered thoroughly but slowly avoiding runoff and soil wash. The planting of cuttings should be done very carefully without damaging the cut-end and the bark. Holes may be punched in the soil with a small stick of appropriate thickness of the cuttings and then cuttings may be inserted. The node and the petiole should not be burried or touched the soil surface. Transplanting into sleeves from rooting beds During favourable season cuttings may take 4 - 8 weeks for callusing and 10 - 12 weeks for rooting. After the roots have grown cuttings should be transplanted to sleeves with a ball of earth.
Fertilizer management Fertilizer is one of the major agro-inputs contributing to the cost of production and productivity in tea plantation. For proper maintenance of the health of tea bushes and to obtain high yield, a well balanced fertilization and manuring is necessary at certain intervals throughout the year. Thirteen mineral nutrients are essential for the growth and development of all plants including tea. For reasons of convenience and tradition, these are usually categorised as follows.
Macro/ Primary			Micro/Secondary
Nitrogen (N) Phosphorus (P) Potash (K)	Sulphur (S) Calcium (Ca) Magnesium (Mg)		Zinc (Zn), Iron (Fe), Manganese (Mn), Copper (Cu), Boron(B), Molybdenum (Mo), Chlorine (Cl)		Aluminium (Al), Silicon (Si)
Organic fertilizers Organic fertilizers have been time-tested materials for improving the fertility and productivity of the soil. They also have a corrective effect on the adverse soil conditions caused by the continuous and excessive use of inorganic fertilizers. Apart from promoting soil aggregation leading to better water holding capacity in coarse textured soils and drainage in heavy soils, organic manures causes favourable changes in soil reaction and enrich the nutrient status of the soil.
Green manure Green manure is a cheap alternative to the use of fertilizer nitrogen. The process also makes a possitive contribution to the maintenance of soil organic matter content at a satisfactory level. Green manuring is a low cost and effective technology in minimising investment cost of fertilizers and safeguarding the productive capacity of the soil without any impoverishment. Trees, shrubs, cover crops, legumes, grasses, weeds, ferns etc provide green manure, an expensive source of organic fertilizer to built up or maintain soil organic matter and fertility. Diagnosis of fertilizer requirements of tea by soil analysis Prior to undertaking planting of tea, representative soil from the area should be analysed for fertility status. This practice is particularly important if the area is outside the traditionally tea growing tract.
Fertilizer recommendations Tea seed and clonal nurseries Nowadays both seedlings and clonal plants are raised mostly in polythene sleeves. The clonal cuttings are either planted directly on to the sleeves or first planted on the rooting beds and then transferred to the sleeves when they developed some roots. There is no necessity to apply manure on the rooting beds. 3 kg of single super phosphate may be thoroughly mixed per cubic metre of soil at the time of preparation of soil for filling the polythene sleeves. Young tea manuring (YTD) containing NPK in the proportion of 2 : 1 : 2 can be used as follows :
Nutrient Condition	Nutrient Kg ha^-1 Year^-1		Remarks
N : P₂O₅ : K₂O	10 : 5 : 10 Or 10 : 5 : 15 where potash in soil is low		One part of fertilizer is mixed with nine parts of sand or powdered earth. As the quantity of fertilizer applied per plant is low, it is advised to increase its volume by addition of dry sand or dry powdered earth.
One tea spoonful of the mixture should be applied to each seedling or clonal plant in a ring little away from the collar. In all 6 to 8 fortnightly applications should be made avoiding contact on the leaves of the plant. Foliar spray, where necessary, zinc and / or magnesium sulphate @ 2 kg of either in 200 litre of water may also be applied. Manuring should start when seedlings or clonal plants have attained about two flush of growth.
At planting 4.5 kg of well rotted organic manure, or oil cake at the rate of 150- 200 gram per pit or bone meal 100 kg ha-1 plus 30 - 40 gram single super phosphate per pit should be used. Concentrated organic manure should be thoroughly mixed with the excavated soil. A fresh stock of oil cake should be fermented by exposing to atmosphere with adequate watering to avoid injury to the root of the plant. Young tea 10 : 5 : 10 mixture of sulphate of ammonia, super phosphate and rock phosphate in 1 : 1 ratio and muriate of potash is recommended during the formative stage but 10 : 5 : 15 is preferable in low K soil (below 60 ppm). Mature tea NPK manuring schedule for mature tea in Darjeeling hills.
Yield range Processed tea (kg ha^-1 ) (Cycle average)	N (kg ha^-1)	P₂O₅ (kg ha^-1)	K₂O kg ha^-1 at available K level
			<60 ppm 60 – 100 ppm > 100 ppm
Up to 600 600 – 1000 1000 – 1400	up to 60 60 - 90 90 – 120	20 20 20	up to 60 60 – 90 90 – 120	up to 50 50 – 90 70 – 100	up to 50 35 – 50 50 – 70
Application of fertilizers and quality of tea The applications of increasing levels of fertilizer led to increased yields. But the question arose as to whether the quality of processed tea changed. The studies undertaken so far are rather subjective and they show much variation in the quality of tea manured differentially. However, this controversy has not yet ended even today. Quality of made tea broadly depends on the composition of leaves, which in turn is influenced by nutrition It is evident from the accumulated findings that the application of nitrogenous fertilizer at a very high dose deteriorated the quality (overall value) of processed tea. However, it has been seen the application of nitrogen at 120 kg ha-1 in two splits retain the Darjeeling quality. It was also observed that if any body likes to go for more splits then it will have less nitrogen per split and quality may not be affected. But single application of nitrogen more than 100 kg ha-1 may affect quality. Different sources of nitrogen like ammonium chloride, urea and calcium ammonium nitrate did not have any adverse effect on liquor characters of tea, nor did they help in improving the general quality of tea. Zinc and other micronutrients do not normally affect quality of marketable tea if they are applied judiciously on the basis of plant requirement. However, application of nutrients will have no effect on quality provided that yield and applied nutrients as so balanced that the amounts of the nutrient in leaves remain within critical limits.