Harvesting of tea & Shoot Growth

This tropic will be discussed in following tropics, pls click on the tropics to see them or just click on the "Harvesting" Button above.

• Introduction to Harvesting or Plucking of Tea Shoots
• Parts of a tea shoot or Physiology of a Tea Shoot
• Generations of Tea Shoots
• Plucking interval or Harvesting interval
• Severity of plucking
• Standard of plucking or Plucking Standard

Manure or fertilizer for Vegetative Propagated (VP) tea Nursery in Sri Lankan weather and climatic conditions

Fertilizer for tea nursery is not meant for fast and high growth in green foliage. It should be focused on the development of the frame of the young tea plant, since; a sustainable crop could not get from a bush with a poorly developed frame of the plant. The formulation of the tea nursery fertilizer mixtures have been done with that scope in mind. 

Basically there are two tea nursery mixtures used in Sri Lanka, namely T65 (MAP) (P-source is mono-ammonium phosphate) and T65 (DAP) (P-source is di-ammonium phosphate).  Apart from the market availability, it doesn’t matter to use MAP or DAP for the mixture. But, T65 (MAP) dissolves fast, so that, it is easier to handle. 

Composition of T65 (MAP) Mixture

Parts by weight	Chemical name of the ingredient	Nutrient content
15	Sulphate of Ammonia	20.6% of N
20	Mono-Ammonium Phosphate (MAP)	20% of N and 35% of P2O5
15	Sulphate of Potash	48% of K2O
15	Epsom Salt	16% of MgO
65 (Total Parts)

T65 (MAP) mixture contains 10.9% N, 10.8% P₂O₅, 11.1% K₂O and 3.7% MgO

Composition of T65 (DAP) Mixture

Parts by weight	Chemical name of the ingredient	Nutrient content
20	Sulphate of Ammonia	20.6% of N
15	Di-Ammonium Phosphate (DAP)	18% of N and 46% of P2O5
15	Sulphate of Potash	48% of K2O
15	Epsom Salt	16% of MgO
65 (Total Parts)

T65 (DAP) mixture contains 10.5% N, 10.6% P₂O₅, 11.1% K₂O and 3.7% MgO

There is no need to use exactly the same mixtures mentioned above, to a tea nursery, but be sure the nutrient content and composition is approximately the same, as indicated.

How to apply the nursery fertilizer mixture to a VP tea nursery (in polythene bags) 

Tea nursery fertilizer mixture is a foliage application with watering cans. If you use T65 (DAP), it should be ground well and make a paste, before dissolving it in water, since DAP is poorly dissolve in water.

It is not advisable to apply fertilizer to the young plant, or planted shoot cuttings, before the roots are emerged. Therefore, the time of the first application of fertilizer is, after 2-3 months of planting.  

Dissolve 35 g of above mixture in 5L of water and apply it onto, approximately 1 m² of the tea nursery, in fortnightly intervals. Generally, with 4 inch diameter polythene bags, 1 m² contains 120 nursery plants.

In about 5-6 months after planting of shoot cuttings in nursery bags, increase the weight of fertilizer up to 70 g/5L water/m^-2 of nursery area. 

Note that, it is compulsory to wash off the fertilizer mixture from foliage with clean water within 15-30 min time, to avoid scorching the leaves due to high concentration of fertilizer. 

Application of Zinc Sulphate (ZnSO₄) to induce bud break in tea nurseries

Branching is important in tea bush because, the higher the number of branches, higher would be the number of shoots harvested. Also, branching must be induced from the lower parts of the main stem of the bush, so that, they would not be cut off in seasonal pruning of branches. Therefore, induce of branching from the base of the main stem is commenced from the nursery stage. 

Foliar application of ZnSO₄ is done to induce bud break at the nursery stage. One week after each application of T65, 14 g of ZnSO₄ is dissolved in 4.5L of water and spray this with a Knapsack (hand) sprayer to approximately 4500 (38 m²) nursery plants. Repeat the application at 4-6 week intervals up to 4 applications per year.

Click her to view fertilizer for Seedling Tea Nursery 

 Well grown Tea (VP) Nursery Plants

Drought Management or Drought Mitigation - in tea cultivation

Drought management is not applied only in a drought but it should be integrated practices from land selection to harvesting of mature teas. Therefore, this tropic is divided into several sub-tropics and discussed separately, by each step.

Selection of land for tea cultivation

The land should be less than 70% of slope, and preferably more than 60-100 cm in depth. Gravel portion of the soil is better to be less than 10% while avoiding hard-pans containing gravel or other hard material. Also care should be paid on the type of soil, although it has no connection with the drought mitigation. Tea is well grown in Red Yellow soils with a good top soil rich with organic matter. 

Land preparation

Land preparation and minimize erosion during that will result in a healthy root system, which helps tea bush to survive in a drought. Always take care to minimize soil erosion in land preparation. Organic matter content in the soil is also a factor affecting water content in the soil. Avoiding heavy rain seasons, preparing the land from the top of the slope in small blocks, avoiding leveling land to a very fine texture, prepare lateral drains alone the couture lines, rehabilitation of the land with grass at least to 18 month time, planting alone the couture, etc. are some of the practices that matters with drought mitigation of tea.

Planting of young tea

A vigorous tea plant will always be face the drought better than a week one. Therefore, selecting a healthy nursery plant is very important. Ground propagated tea nursery plants will have damaged roots when pull out for field establishment. Select a good bag-planted tea plant for planting. Well branched tea plant with a healthy root system makes the tea plant recover and establish in the field, early. The nursery bag should be at least 6 inch in depth and 4 inch in diameter. Never cultivate plants from ground nurseries. Always go for bag planted nursery plants.

Planting is done in couture lines with spacing of 2 feet withing the row and 4 feet between two rows. Use a thatching between tea rows after planting. 

Management of tea bush

Stop harvesting in severe and prolonged droughts. When the drought is not so severe, fine harvesting method must be adopted (harvest only the bud and two leaves, leaving a leaf to the plucking table - so called as mother leaf plucking).

Always avoid pruning tea bush into drought seasons. Pruning must be done with the onset of a rainy season. Also, care must be taken to leave 2 - 3 healthy branches un-pruned in the bush to facilitate adequate photosynthesis and detoxification of toxics synthesized during root death due to branch pruning. Never harvest shoots in remained branches (lungs). Bury pruning branches in every other tea inter-row space. This will increase the organic matter content in soil increasing the water holding capacity. In the same time rain water will better absorbed into soil due to decreasing in the speed of runoff water. 

Avoid manure application. This may harmful in drought since the moisture in the soil sap is inadequate, and thus causing nutrient concentration in the soil sap more concentrated than tolerable to the tea roots.

Weeds compete with tea plant for moisture. Therefore remove weeds the tea land at the early state of the drought and preferably apply a thatching or mulch. Hand pulling and scraping weeds will loose the top soil layer causing more moisture evaporated from the soil. If the drought is prolonged and weeds are still there, slash weeds with a knife without pulling or scraping. Chemical weeding may be practiced in such a situation without affecting much to soil moisture.

When tea plant continuously producing shoots, and harvested, it adds an additional stress to the plant. Therefore, skiffing (removal of 2 – 3 inch top layer from plucking table) can be practiced, in prolonged drought conditions, so that, the production of shoots is temporarily reduced. This will reduce the annual yield but, in return, bushes will not die. 

Chemical Applications in Drought Management

Water is removed through transpiration form the tea leaves. If we can reduce the transpiration, that will help the tea bush to withstand the drought conditions. Spray kaolin or Kieserite to the foliage. Kaolin will cover the tea leaves as a thin layer on the leaves while Kieserite will close the stomata reducing transpiration. Care must me applied, when applying Kieserite to foliage, so that the solution would not too concentrated (less than 5%), sucking out the water in the leaves.