The Right brothers introduced tea farming in Kenya in 1903, in preset day Limuru. Large-scale commercial agriculture started in 1924. The colonial administration established the Tea Board of Kenya to regulate tea farming in 1950. During this period, small-scale tea farming was prohibited. The colonialists did this to prevent Africans from directly competing with white farmers.
Fast forward to today, tea is now one of the leading foreign exchange earners in the country. It contributes around 4% of the total GDP. In addition, tea farming supports more than 0.64 million Kenyans. The success of team farming in Kenya is attributed to KARLO- Tea Research Institute. This research body has developed high-yielding plants that have increased productivity per unit area.
The History of Tea Research in Kenya
Tea research was done in 1949 by Brook Bond Liebig Co.LTD in Kericho. East Africa Tea Growers later acquired the company and renamed the Tea Research Institute East Africa {TRIEA}. TRIEA collapsed when the then East Africa Community broke up in 1977. After the breakup, the Kenyan government formed the Tea Research Foundation of Kenya {TRFK}.
In 2014, The Tea Research Foundation of Kenya was renamed the Tea Research Institute {TRI} and put under the Kenya Agricultural and Livestock Research Organization {KARLO}.
Tea Farming in Kenya
Tea falls under the Theaceae family and has two main varieties, var. assamica and var. sinesis. Over time, new types, such as the Camellia Assamics, a Chinese variety, have emerged. They can attain a height of 30m and have a lifespan of 1500 years. Under optimal conditions, a good tree should produce a yield of 3.5 kg yearly.
Tea is propagated using a vegetative material. The plants can be raised from tissue culture or seeds. It is important to note that seed propagation is not commonly used in Kenya, as farmers prefer tissue culture because it is cheaper and economical on space.
Nursery
Tea farmers should protect tea seedlings from wind and close to a water source. Sleeve Nurseries are best, mainly if the trees have been vegetatively propagated. The nursery should have a pH of 5 – 6 and have well-drained soil. In addition, the nursery should not be placed in a low-lying area because the wetness can cause diseases. Also, the nursery might be affected by frost during the dry season.
Seedlings should be transplanted when their roots reach the bottom of the sleeve, and they grow atleast 20cm tall.
How to select tea tree cuttings
Trees should be healthy and should have grown for at least six months without being cut. Mother bushes should be pruned at least twice a year using a straight standard cut across the branch. If the branch had been pruned before, ensure the second cut is at least 2.5cm from the previous cut.
Farmers should cut new shoots seven months after pruning. Farmers should also ensure that stems do not attach to the mother Bush for more than seven months. This is because the branches become stiff, making them difficult to cut.
How to plant cuttings
Farmers should ensure that the leaves do not touch the ground when planting the cuttings. After cutting, ensure the plant is gently watered to protect it from displacement.
How to maintain the nursery
Nurseries should be inspected atleast once a week. Tea farmers should check the nursery for diseases, insects, and weed growth. Weeding should be made by hand, and the beds should be watered every 21 days. Tea tree nurseries should be protected from direct sunlight by using UV nets.
Field Planting
Sleeved plants are ready for transplanting when roots have reached the bottom of sleeves and also have at least 20cm (8 in) of top growth. At the time of transplanting, the cylinder of soil in sleeves should not be dry. The plants must be handled careful to avoid cracking the cylinder the cylinder of soil and perhaps the roots and they should be stacked carefully and tightly on any vehicle taking them to the field.
A number of containers can be carried on a wheelbarrow. This avoids all unnecessary handling of the sleeves. The sleeves should be protected from direct sunshine at all times until planting is completed to prevent damage the roots. The holes should be 15cm to 20 cm deeper than the sleeves and double their diameter, though the minimum should be 25. For standard 25cm long x 6.25cm diameter the sleeves the holes will be 40cm x 25cm.
Use 15gm Diammonium Phospate (DAP)/Triple super phosphate per planting hole or 30gm of single super phosphate. Mix fertilizers thoroughly with soil from planting holes.
Fertilizer Application
These are tea bushes, which are used as regular sources of cuttings. Removal of nutrients from mother bushes is at a much greater rate than from plucked tea. Bushes weakened by lack of nutrients (or because of pests, diseases, hail, drought, cold) produce less cuttings, which strike less easily and grow more slowly in the nursery than those from bushes producing vigorous shoot growth after pruning.
Mother bushes should be given twice as much fertilizer, of the same kind, per year as applied to plucked bushes of the same age. Apply the fertilizers in at least two doses each year. These can be made two or three months after each pruning. When a few bushes are pruned each day, fertilizer can be applied to each bush immediately it is pruned. If it is anticipated that two or three months after pruning there will be no rain, then the fertilizer should be applied immediately after pruning.
For quick infill establishment, nitrogen, phosphate and potash fertilizers must be used in the planting hole in proportion to the size of the hole. For a hole 60cm diameter by 60cm deep, use 115g DAP and 115g sulphate of potash (SOP). Three months after planting apply NPKS 25:5:5 to each plant to each at the rate of 50g per plant and thereafter as applied to the rest of the field.
Young tea is tea of any age from the time of transplanting to the time of pruning at the end of its first cycle, after about three years’ plucking (total of five years). In these five years, the plants need nutrients to maintain their health and extra fertilizer to encourage the development of strong root and branch systems, which will support vigorous cropping at maturity.
The fertilizer should be a compound or mixture providing N, P, K and S in the proportions 5:1:1:1, or more concentrated in P and K. Young tea must be kept clear of weeds and other crops grown in the tea are provided with fertilizer additional to that applied to tea.
Any convenient nitrogenous fertilizer should be applied broadcast to the soil surface, to provide nitrogen at the rate of 12kg/ha, immediately before mulch is first applied to a field. This is to compensate for the temporary loss of nitrogen from the soil while the mulch breaks down.
Time of application of fertilizers
Tea under severe nutritional stress should receive a curative fertilizer application as soon as practicable. If nitrogen is the deficient nutrient, fertilizer application should wait until the grower can be sure that rain will follow within a few days. Phosphate and potassium fertilizers run little risk of loss by chemical or biological means if they remain on the soil surface in dry weather.
Normal fertilizer applications should avoid prolonged cold or wet seasons, and if they are made during dry weather they should be delayed until it appears that rain will fall within a few days. The first application in a pruning cycle should be at the time of tipping, whether the normal fertilizer or a supplementary fertilizer to remedy mild deficiency is concerned. It is assumed that all prunings will be left in the field and decomposing pruning‐leaf and soft twigs will return nutrients to the soil, making it unnecessary to add to this before tipping. There is also risk of the nitrogenous fertilizer components reacting with fresh mulch resulting in lowered efficiency of this nutrient.
The more highly weathered mulch at tipping time could be considered to be safer in this respect. Timing of the last application in a cycle would depend on the anticipated cropping pattern in the last few months. An interval of less than six months before pruning may be too short for full benefit of the fertilizer to be shown. Severe nutrient deficiency can retard recovery from pruning. If the cause is detected in time, it would be preferable to make a fertilizer application before pruning, rather than after.
The time interval before pruning should be several months, and if the vigour of the bush is very poor, pruning could be delayed until there is evidence of improved growth. There is no evidence to show that heavy application of a fertilizer nutrient can improve recovery from pruning on a bush inreasonably balance nutrition.
Practical considerations may overrule some of these suggestions. The first consideration should always be given to planning a fertilizer programme that allows efficient and even fertilizer distribution.
Split applications
Split applications do not significantly improve yield in mature tea. However, a program based on a high‐analysis compound fertilizer plus a straight fertilizer could conveniently be planned to allocate the fertilizers to different seasons. If so, it is advised that the multi‐nutrient fertilizer be applied before the main cropping season. If it can be conveniently arranged, the same fertilizer should be allocated to the last application in a cycle.
Splitting the annual fertilizer program may be adopted to lessen the risk of increasing already excessive crop in certain seasons. If this is done, the overall efficiency of the fertilizer may be reduced in terms of the quality of the crop produced.
Seven things to avoid when planting tea
seven things to avoid when growing tea
- Avoid planting tea in areas with poor drainage or heavy clay soil, as tea plants require well-drained soil to thrive.
- Do not plant tea in full shade, as tea plants need at least 4-6 hours of sunlight daily to grow correctly.
- Avoid planting tea in areas with extreme temperature fluctuations, as tea plants prefer a consistent, moderate climate.
- Avoid over-watering tea plants, as excess moisture can lead to root rot and other problems. Water the plants deeply but infrequently, and allow the soil to dry out slightly between watering.
- Avoid using chemical fertilizers on tea plants, as these can interfere with the delicate balance of nutrients in the soil and potentially harm the plants. Instead, use organic fertilizers or compost to give the plants the necessary nutrients.
- Avoid planting tea plants too close together, as they need room to grow and spread out. Plant them 3-4 feet apart to give them enough space to develop.
- Avoid planting tea plants in soil that has yet to be correctly prepared, as this can lead to poor growth and yield. Make sure to loosen the dirt, add compost or organic matter, and adjust the pH to the optimal range for tea plants (pH 6.0-6.5) before planting.
Several diseases can affect tea trees, impacting their growth and yield. Fungal infections, such as leaf spots, rust, and black fungus, can be prevented by ensuring proper air circulation. In addition, the diseases can be controlled by avoiding overcrowding and applying a preventative fungicide.
Bacterial blight, which causes leaf spots, stem cankers, and dieback in tea plants, can be controlled by pruning affected branches and applying a copper-based bactericide. Tea mosaic virus, a viral disease that causes mottled and distorted leaves, can be controlled by removing and destroying infected plants to prevent the spread of the disease.
Tea scabs, a fungal infection that causes raised, scabby lesions on the leaves and stems of tea plants, can be controlled by pruning infected branches and applying a fungicide.
Root rot is a fungal disease that can attack the roots of tea plants and cause yellowing leaves, wilting, and death can be controlled by improving soil drainage, avoiding over-watering, and applying a fungicide.
Spider mites are tiny pests that can damage tea plants by sucking the sap from the leaves. They are controlled by using a horticultural oil or insecticidal soap or by introducing predatory mites to the area. Overall, proper care and management can help prevent and manage diseases in tea trees and ensure healthy growth and development.
