Kolkata: A small green-fly, not measuring more than 5mm in length, has started taking a heavy toll on the Darjeeling and Assam tea industry with production of Darjeeling tea dropping to a record low in 2024. Experts have blamed it on the climate crisis.
Data shared by the Tea Board of India reveals that the production of this world-famous brew, known for its rich aroma and unmatched flavour, dropped to 5.6 million kilos in 2024, the lowest in recent times. In 2022 and 2023 the production of Darjeeling tea was 6.9 million kilos and 6.01 million kilos respectively.
“The tea industry in West Bengal and Assam is facing a severe challenge due to widespread infestation of green flies, a pest that has emerged as a major threat over the past two years. This sap-sucking insect has caused significant damage to tea plants particularly during the dry months leading to yield reductions ranging from 11% to as high as 55%,” said Joydeep Phukan, secretary and principal officer of Tea Research Association (TRA).
In West Bengal, tea is grown in the hills of Darjeeling at an elevation of 600m to 2000m and in the foothills, the Terai-Dooars region, in Alipurduar Jalpaiguri and Cooch Behar districts.
Terai and Dooars tea also witnessed a decline during the same period. In the Terai region, the production was 172.3 million kilos in 2022 and 189.8 million kilos in 2023. In 2024 it came down to 158.45 million kilos. Tea production in the Dooars was 234 million kilos in 2022 and 237 million kilos in 2023. It dropped to 209 million kilos in 2024 due to the fly and climate crisis.
In 2022 and 2023 the total production of tea in West Bengal was 414.08 million kilos and 433.54 million kilos respectively. The production dropped to 373.48 million kilos in 2024. Assam too registered a decline. While the production of tea in Assam was 688.70 million kilos in 2022, it was 688.33 million kilos in 2023. In 2024 it dropped to 649.84 million kilos.
While answering to a question on the decline of production of Darjeeling tea, Jitin Prasada, the Union minister of state for commerce and industry, told the Lok Sabha on April 1 that production of Darjeeling tea depends on various factors such as old and senile tea bushes, conversion to organic tea which leads to lower yields and effects of climate change.
“Because of the erratic weather triggered by climate change the yield has dropped. The climate has been very erratic last year. Because of this change in climate, pest attacks have also increased in the gardens resulting in huge loss of production,” said Hemant Bangur, chairman of Indian Tea Association.
While the India Meteorological Department has already stated that the year 2024 was India’s warmest on record with the annual mean air temperature 0.65 degrees Celsius above normal, a tea estate in West Bengal recorded at least 33 days when the day temperature soared above 40 degrees Celsius mark in 2024. In 2023 the number of such days was 29. Barring 2014 and 2012, the garden hardly witnessed such high temperature.
“Attacks of pests on tea plants have increased over the years because of the effects of climate change – rising temperature and erratic rains. Greenflies, in particular, have emerged as a new challenge over the past two years. Earlier they were considered as seasonal pests which were active during the months of May and July. But now such attacks are being reported throughout the year,” said Bidyananda Barkakoty, advisor to North Eastern Tea Association and owners of Mahalaxmi and Nandapur tea estates in Assam.
Experts said that there are growing concerns over the possible invasion of a modified and more aggressive greenfly strains. Even though tea estates have been using various chemicals, they have largely proven ineffective against this pest.
“The Tea Board of India recommended nine specific chemical formulations but they too failed to curb the menace. Tea plants after being attacked by this fly is becoming vulnerable to secondary infections such as Fusarium dieback, which has been affecting plantations for several years,” said Phukan.
Scientists at the Tocklai Tea Research Institute of TRA are presently investigating new strategies to combat this new threat. While researchers have narrowed down on one such compound known as Chlofenapyr10%SC, it now needs the stamp of the Central Insecticide Board for use in the tea gardens.