The diversity in climate in the tea growing areas in immense and it is a significant feature in the wet and intermediate zones of Sri Lanka.
The rainfall is distinctly seasonal with two peaks occurring over most parts of the country, including the wet zone, where tea cultivation is prevalent.
All most all the climatic parameters such as solar radiation, rainfall, temperature, vapour pressure deficit and wind effect the growth of tea.
- The amount of rainfall and its distribution are the most important factors that affect the productivity of tea.
- Rainfall requirement depends on the evaporative demand of the atmosphere, soil, type of cultivar and its growth stage.
- An annual rainfall of 2500-3000 mm is considered to be optimum with a minimum requirement of 1200 mm.
- In dry months, the amount and distribution of rainfall affects the productivity of tea.
- An even distribution, without marked seasonality, is ideal for tea growth.
- An acidic soil is the most important requirement, with a pH of 4.5-5.5 being ideal.
- Soils should be deep, preamble and well drained.
- Ideally, soils should be at least 90 cm in depth, contain less than 10% gravel in the profile and have less than 10% of the surface area covered by boulders and rock outcrops.
Agro-Ecological Regions (AERs)
- The climatic requires of tea are satisfied by almost the entire wet zone and certain regions in the intermediate zone.
Agro-ecological regions suited foe tea growing in Sri Lanka
|Wet||WU1, WU2a, WU2b, WU3|
|WM1a, WM1b, WM2a, WM2b, WM3a, WM3b|
|Intermediate||IU1, IU2, IU3a, IU3b, IU3c, IU3d, IU3e|
|IM1a, IM2a, IM2b, IM3c|
Principal planting districts in different agro-ecological regions (AERs)
|Agro-ecological region||Planting districts|
|WU2a, b||Pussellawa, Pundaluoya, Dimbula, Dickoya|
|IU1||Kellebokka, Knuckels, Rangala|
|IU3a, b, c, d, e||Badulla|
|WM1a, b||Morawak Korale, Ratnapura|
|WM3a, b||Kandy, Balangoda, Rakwana|
|IM2a, b||Madulsima, Passara|
|WL1a||Ratnapura, Kaluthara, Kelani Valley, Galle|
|WL2a||Kegalle, Ratnapura, Galle|