Impact of Climatic Factors &

Adaptation Measures

On Productivity of Tea Plantations

In Sri Lanka

M.A.Wijeratne

Tea Research Institute of Sri Lanka

Impact of the Tea Industry

Foreign exchangeEmployment

Farmer’s Income

Environment

Tea Growing Regions in Sri Lanka

Major…

U- Up country (>1200m amsl) T:10-27 oC

M- Mid country (600-1200m amsl) T:19-30 oC

L- Low country (<600m amsl) T:21-34 oC C

Agro-Ecological Regions….

Up country wet zone (WU 1-3) RF:1400->3175mm

Up country Intermediate zone (IU 1-3) RF:1150->2150mm

Mid country Wet zone (WM 1-3) RF:1250->3150mm

Mid country Intermediate zone (IM 2) RF:1150->1400mm

Low country Wet zone (WL 1-2) RF:1900->2525mm

WL

WM

IM

IU

WU

Up-Int.

Up-Wet

Low-Wet

Smallholder

Most Influential Environmental Factors…

Rainfall (>1200mm)

Temperature (18-25oC)

Present

Future (with CC)

Rainfall

Temperature

CO2

Drought damage in tea

Region Most Vulnerable to CC..…

0

20

40

60

80

100

120

140

160

180

1980 1982 1984 1986 1988 1990 1992 1994 1996 1997 1999

Year

Total production (Mn.kg)

Low Country

Up Country

Mid Country

56%

26%

18%

Drop: 26%

Loss: 70 Mn USD Drought

1992

Methodology

Data Collection

•Estates (RF & Productivity)

•Met Stations (RF & Temperature)

•TRI Experiments (CO2 & Adaptations)

Problems encountered

•Missing data (non-continuity)

•Reliability

•Classification (Elevation)

Methodology

Data Analysis

•Trends

•Correlations

•Extreme events

Problems encountered

•Variability (Variety/Management/growth

•Missing data

Productivity

Time

National Productivity

0

200

400

600

800

1000

1200

1400

1600

1800

19341938194219461950195419581962196619701974197819821986199019941998

Year

Productivity (kg/ha/yr)

Drought

1992

1 2 3 4 5

S1

S30

500

1000

1500

2000

2500

Productivity in different regions & Drought Effects

IU WM IM WL

POTEN.

1991

1992

28%19% 14% 25%

26%

WU

Productivity vs Environmental factors

Up country wet zone (WU 1-3) RF:1400->3175mm

YIELD=116+0.23 RF: r2 = 0.15 (p<0.05)

Up country Intermediate zone (IU 1-3) RF:1150->2150mm

YIELD=76.7+0.32 RF: r2 =0.21 (p<0.05)

Mid country Wet zone (WM 1-3) RF:1250->3150mm

YIELD=78.7 + 0.75 RF: r2 =0.77 p<0.05)

Low country Wet zone (WL 1-2) RF:1900->2525mm

YIELD=62.9 + 0.25 RF: r2 =0.66 (p<0.05)

Rainfall (mm)-Dry month & Monthly yield (kg/ha)

PRELIMINARY RESULTS

Productivity vs Environmental factors

Up country wet zone (WU 1-3) RF:1400->3175mm

Y= -219+24.5 T: r2 = 0.12 (p<0.05)

Up country Intermediate zone (IU 1-3) RF:1150->2150mm

Y= -310+25 T: r2 =0.13 (p<0.05)

ENTIRE REGIONS

Y= -508+63.7 T – 1.46 T2 (p<0.05)

Temperature & Monthly yield (kg/ha)

Productivity vs Environmental factors

CO2 vs Mean yield (kg/ha/wk)

1 2 3 4 5 6

S1

051015

2025

30

35

40

45

Month

Yield

Enriched

Control

45%18%

600ppm

Adaptations

Irrigation

Supply of water/nutrients

Availability of water resources

Limitations

Yield increase (wet): 50->100%

Yield increase (dry): >300% increase

Adaptations

Soil improvements

Addition of compost

Burying of prunings

25% Yield Increase per 1% OC (8-10 tons of OC/ha/ year)

Enhanced Microbial activity

Increased CEC

Enhanced porosity & WHC

Improved Soil Structure

Limitations

Availability of resources: Labour & Material

Adaptations

Shade management

LimitationsManagement difficulties

Control of temp:(2oC) /RH

Addition of GM: (5-20t/ha/yr)

Adaptations

Intercropping

Provision of shade

Other benefits

Limitations

Poor returns compared to monocropping of tea ??

Adaptations

Timber/Forest/Grass

Source of green manure

• Preserve environment

Limitations

Social implications ??

Diversification of marginal tea lands

THE END…