Can climate-resilient clones save Darjeeling tea?

Like many tea drinkers across the country who can’t imagine life without their favourite cuppa, Debasree Majumder’s day starts and ends with her staple Darjeeling tea. “I have four cups a day. It enlivens me. My family swears by Darjeeling tea,” says the 51-year-old homemaker from Kolkata in West Bengal, the second-largest tea producing state in India and home to the much loved Darjeeling tea gardens. 

But something is amiss lately, feels Majumder. According to her, the ‘champagne of teas’ is losing its original taste and aroma. “Darjeeling tea doesn’t seem to have the sensory appeal as it used to do earlier. I don’t know what it is but something is missing,” she says.

Majumder might be clueless about the reason but she’s right about her favourite tea not being the same anymore. Researchers believe climate change has tampered with the well-recognised flavour for which Darjeeling tea is treasured across the globe. However, scientists are searching for solutions in climate-resistant planting materials, genomics and organic cultivation.

Two leaves and a bud struggle against climate change

First planted in the early 1800s, the unique aroma and flavour bouquet of Darjeeling tea (‘Muscatel’ and ‘Exquisite Banquet’) reflects the local climate, temperature, soil conditions, sloping terrain and meticulous processing.

Teas are grown at elevations ranging from 600 to 2000 metres above sea level and require a minimum of 50 to 60 inches of rainfall in a year. A temperature range of 18 degree Celsius to 30 degree Celsius and relative humidity of 95 to 98 percent suits the tea best. 

However, in the last two decades, factors including climate change have thrown a wrench in tea production.

According to a long term study by Darjeeling Tea Research and Development Centre (DTR&DC) in Kurseong, Darjeeling district, West Bengal, a temperature rise of 0.51 degree Celsius from 1993 to 2012 and decline in annual rainfall by 152.50 cm and relative humidity by 16.07 percent in those two decades of study led to overall production declines in tea.

The production of Darjeeling tea that stood at 11.29 million kg in 1994 dropped to around 8-8.5 million kg in 2018.

“We must acknowledge that climate change is a global issue. Strong winds, frequent frost, hail, and excessive rainfall have become detrimental to the production of high-quality tea. The reduction in sunshine hours and infestation of different types of insect pests and diseases has also impacted the tea quality and the quantity,” says Mrityunjoy Choubey, senior scientific officer, DTR& DC, Tea Board, Kurseong.

The reason of reduction in yield may not be solely due to climatic change but there are other drivers such as switching over to inorganic from organic cultivation practices, age of tea bushes, soil erosion that could be the behind the gradual declining in production of Darjeeling Tea in general and DTR&DC in particular, said the study.

Keeping the flavour brewing

It’s not all gloom and doom, though, for tea-lovers. Researchers at the DTR&DC are working on new planting materials (tea clones) that would not only be resistant to climate change but would also ensure that there is no change in the flavour of Darjeeling tea.

“The purpose was to find the clones that would be at par or better with the best clones and overcome the challenges of climate change. We have zeroed on in 3-4 vegetative clones that are stress-tolerant and deal with the issues plaguing the Darjeeling tea. We are planning to release them in the tea gardens. We are hopeful that it would be a huge hit in the coming future and overcome climate issues,” Choubey added. 

Additionally, a tea genome sequencing project involving six partner institutions to develop climate-resilient tea plantation methods using the latest molecular tools and techniques is also on.

Good news for growers as well

Experts insist that the superior quality of clones would also be beneficial for growers. “It would enhance quality and production and thus growers would get more returns,” says Biswajit Bera, Director (Research), Tea Board India, adding the agency is also studying soil microbiology to improve soil fertility.

Tea Board India is a government agency representing different sections of the tea industry. The Board is also working on in-situ conservation in the hills in order to preserve local seeds.

“We have found that planters bring clones from Assam because they are drought-resistant but compromise quality in the bargain. So, we are prioritising local seeds so that consumers get the real taste of Darjeeling tea and this way we also preserve the Darjeeling tea strain,” Bera said.

Additionally, a tea genome sequencing project involving six partner institutions to develop climate-resilient tea plantation methods using the latest molecular tools and techniques is also underway.

Tea growers couldn’t be happier, having borne the brunt of climate change on the Darjeeling tea market. “We witnessed an overproduction of 30 to 40 percent of Darjeeling tea in April, this year due to erratic weather. But the quality of overproduced tea is rubbish and failed to attract foreign buyers. The uneven rainfall in March led to free flush, resulting in poor quality because the labour shortage delayed the plucking periods,” says Sumon Majumder, general manager (export and marketing), Darjeeling Impex Limited, which runs Namring tea estate, one of the largest tea gardens in Darjeeling.

Manpower shortage has hit the industry hard because of (among other reasons) the lack of interest of the educated, younger generation of pluckers who find better employment in other professions.

Given the dearth of pluckers, cutters (shears which are used to cut roses, so cutters can be replaced) are used which impact the quality to some extent. The labour shortage has also increased the tea plucking rounds, from seven days to 10-12 days. Importantly, it is the first time in the 165-year-old history because of the large scale absenteeism of the workers.

Further, the sale of Darjeeling tea has fallen because people are not drinking too much tea due to the excessive heat and humidity this year, explained Majumder.

The market is still reeling from the three-month long statehood agitation in 2017 in the Darjeeling hills that virtually shut down the area for 104 days.

“The major foreign buyers, like Japan and Germany, procured tea from other countries such as Nepal during the agitation. They still have the old stock and have clearly told us that it would take at least another year before they buy tea from us. Exporters have also incurred losses,” Majumder adds.

Plains mirror the situation of the hills

Climate change has hit tea gardens in the plains too, wreaking havoc on the tea-growing areas in the Dooars and Terai plains in West Bengal. 

“Pest infestation has increased due to climate change. Tea mosquito bugs (Helopeltis sp.) and looper caterpillars (Achaea janata) have been destroying the tea gardens. Erratic heavy rains have stripped the soil of fertility,” says A. Babu, deputy director and senior principal scientist, Tea Research Association, North Bengal, adding that measures are being taken to prevent further damage. 

Shade trees are being planted to protect the tea bushes from direct rays of the sun and preserve moisture in the soil. Organic tea cultivation is also being promoted to deal with climate change. “We have also developed two clones (TV-34 and TV-35) that can withstand climate issues and also retain the same flavour in the produce,” adds Babu.

The cool weather conditions in hills act as a barrier for pests infestation but the hot and humid conditions lead to their intrusion. The erratic rainfall caused by climate change takes away the fertility of the topsoil and exposes hard rocks. Organic farming is useful because it involves vegetative munching using vermicompost that helps to maintain the temperature of the plant even in excessively humid conditions. 

But experts rue that most tea garden owners are yet to wake up to the realities of climate change. Pranab Kumar Biswas, who runs the Centre for Mitigation of Climate Change and Global Warming in Siliguri, says that there has been 17.6 percent departure of rainfall from 1901 to 2015, based on his climate study spanning a hundred years.

 

Banner image: Scientists claim to have developed climate-resilient clones that can save the day for the world-famous Darjeeling tea from climate change. Photo by Narayan G. Maharjan/Flickr.