Introduction to Tea Nursery
Tea is the most popular drink in the world after water and there are many health benefits of drinking tea. Today tea cultivation is prevalent in the many countries in the world. For fertile tea cultivation largely affects the quality plants obtained from a nursery. Therefore it is important to know about tea nursery management which is very essential step of tea cultivation.
Nursery is the first step of the planting program of agriculture production. Tea nursery management is one of the very important operation in tea cultivation because this is the initial stage of establishing quality and vigorous tea plant. The primary objective of nursery management is to raise healthy and uniform plants from suitable cultivars with minimum casualties over an appropriate period of time with a minimum cost. A good nursery plant should be in height about 30cm comprising 15 leaves with 2-3 side branches, and a well-developed root system.
Essential Steps of Tea Nursery Management
- Identification of Mother Bushes/ Selection of Cultivars
- Preparation of Mother Bushes
- Selection of Soil
- Nursery Site Selection
- Fumigation and Bagging
- Collection of Shoots
- Method of Taking Cuttings
- Laying of Cuttings
- Shade Management
- Pest and Disease Control
- Encourage Lateral Spread of Plants
- Observation of Growth
Identification of Mother Bushes/ Selection of Cultivars
The selection of cultivars both for replanting and infilling depend on the desired characters such as high yielding ability, quality of the made tea, resistance to pests and diseases and tolerance to overcome some climatic limitations such as drought and also plant should assists to produce healthy, vigorous and uniform plants in the nursery.
Preparation of Mother Bushes
The multiplication plots should be situated in good soil where gently slope and land near to the nursery. To stimulate the growth of lateral branches, it was advised to remove the auxiliary buds of newly grown shoots after pruning about 2 weeks prior to obtain shoots from mother bushes to remove apical dominancy and then followed by a foliar application of Zinc Sulphate and 2 –3% Urea mixture to induce growth lateral buds.
Selection of Soil
Loamy soil with a pH of 4.5 -5.5, sieved from No. 3 and No. 4 meshes should be taken. Grass soil was taken which has the ability to hold up water with sands for easy draining by removing unwanted particles. Sources of soil should be grass soil, Patna soil, jungle soil or sub soil.
Nursery Site Selection
The site should be centrally located, proximate to water sources, soil and planting materials with a good drainage. Absence of overhanging branches of trees and protected from wind which should be the most probably concerned in regarding the selecting of nursery site. It should not have shade trees or overhanging branches of trees.
Fumigation and Bagging
Soil fumigation should be done to eradicate nematode infestation at the preliminary stage in the nursery by adding 800 ml of Metham Sodium or 500 g of Bazamid per 1 cube of soil after sieving from No. 4 mesh. Then it is covered for three weeks using 500 gauge black polythene. Soil solarization is also practiced as a soil treatment. The covered soil should be mixed well after the 9th, 12th, 15thand 21stdays. Bags were prepared from 150 gauge transparent polythene with a height of 9” and width of 5” and few holes were punched at the bottom of the sleeves. Bags were filled with moisten fumigated soil by gently pressurizing the soil towards the polythene sleeve without keeping air pockets in it. Then bags should be kept for 2 -3 weeks to settle down.
Collection of Shoots
Generally 3-5 suitable cuttings per shoot and 15-25 shoots could be obtained from a mother bush. Vigorously grown erect shoots were collected early in the morning. Lateral branches were not being taken.
Method of Taking Cuttings
“Single nodal cutting” is the ideal form of the vegetative part for planting in nursery. These cuttings were taken from semi hard wood, middle portion of the shoot leaving the apical tender portion and the basal mature portion. Recommended length of a cutting is 2.5-3.8 cm. Cuttings with flower buds, over grown shoots and damaged mother leaf containing cuttings were discarded. The cuttings were dropped into a Cu fungicide solution container immediately after the cuttings were obtained. This was done for preventing the Blister blight attack initial stage in the nursery and dried out. The ideal shoot that we had taken from healthy shoot was as follows.
Laying of Cuttings
The cuttings were vertically inserted down to the wetted soil and gently pressed by the fingers. Only one cutting was planted in one bag but bags at either sides of the bed can be provided with two cuttings in order to use in resupplying casualties. The leaves were oriented in a way to avoid overlapping with adjacent leaves. Cuttings with overgrown shoots, axillary flowery buds and damaged mother leaf were rejected.
Cuttings should not be exposed to direct sunlight and therefore optimum shade was supplied. There are different types of shades such as low shade with bracken fern was used as shade-providing method and using a net that reduces the sunlight by about sixty percent.
Fertilizer application should be commenced only when cuttings have rooted Initially,about35g of T65. (10.9% N, 10.8 P2O5, 11.1% K2O, 3.7% MgO) in five litter of water for 1 square meter (120 plants) at fortnight intervals should be applied and the dosage should be gradually increased to 70g after two months and should continue. After fertilizing, the plants should be washed with fresh water to prevent scorch. To enhance early bud break and for active growth of plants ZnSO4 can be applied as foliar application. 14g of ZnSO4 in for five litters of water can be sprayed by using Knapsack sprayer for 4500 plants about a week after the first application of T 65. (10.9% N, 10.8% P2O5, 11.1% K2O, 3.7% MgO).
Pest and Disease Control
At the stage of nursery, few pests and diseases can be observed. Tea Tortrix, Shot-hole Borer, and Mites are possible pests that could be attack nursery plants. Blister Blight was observed as a prominent disease of nursery plants. At the nursery stage all these pests and deceases were mostly controlled by chemical methods.
Encourage Lateral Spread of Plants
Removal of the terminal bud of the plant at 4 -5 leaf stage is called dis-budding. This was repeated in auxiliary shoots, when they have grown out and this called dis-budding. The bud and 2 to 3 leaves were removed at 7 to 8 leaf stage of plant and this process called thumb nailing.
Observation of Growth
When the plants are grown up to 4-5 months, re-staking and hardening will be conducted. Re-staking of plants is very important practice to be done in nurseries. This can be conducted in three stages according to the growth. Objective of re-staking is to provide correct inputs, improving the aeration and drainage in the bag and removing the moss growth. During Hardening off, plants are gradually exposed to sun light starting from 5-6 months of age. The period of exposure then expanded gradually and finally the shade will be removed completely