100 Years of Tea Research:

Need to regenerate soil fertility

Declining soil fertility is a major issue that the Sri Lankan tea sector is facing along with the aging plant stock, which act as a vicious cycle.  Aging creates bush death creating open spaces (vacancies) in the plant stand, which are highly susceptible to erosion during rainfall.  Inadequate soil conservation measures exacerbate erosion and loss of fertility.  In maintaining soil fertility, soil organic matter (SOM) plays a crucial role by increasing the soil’s capacity to retain water and nutrients added as fertiliser.  Higher temperatures in the low-country, where a substantial portion of the tea production comes from, increase the natural decomposition of SOM leaving very little in the soil unless it is supplemented with organic material such as loppings of shade trees or prunings from tea bushes.  The TRI-recommended GAPs for soil fertility management are not practiced optimally by a majority of smallholders who contribute 75% to Sri Lanka’s national tea production.  In order to address this issue, the Ministry of Plantation and community infrastructure, the TRI, the RPCs and the smallholder representative organisations have come together to initiate a comprehensive set of practices for regenerating soil fertility in tea plantations.  This programme for ‘regenerative agriculture’ is supported by international organisations as well.

Need to address the high cost of production

At present, Sri Lanka has the highest cost of production (COP) among the tea-producing countries.  At the current costs of key inputs such as fertiliser, agrochemicals and labour, the COP is around Rs. 1200 per kilogram of made tea for the RPCs and around Rs. 800-1000 per kilogram among the smallholders.  Labour, fertiliser and agrochemicals are major components of the COP.  Both the shortage and high cost of labour necessitate introduction of mechanisation of all processes in the production line.  In this regard, introduction of new technologies such as drone application of fertiliser has potential and is being adopted already by some RPCs and individual growers.  Here, the TRI has initiated collaborative research with some of these practitioners to optimise the process of drone application as protocols, guidelines and procedures are not currently available for tea.  Increasing the efficiency of field cultivation practices and the manufacturing process in the factory is another strategy to reduce the COP.  In this regard, use of ‘higher generation’ fertilizers such as encapsulated slow-release fertilisers while improving the soil organic matter to increase the soil’s nutrient retention capacity is being promoted by the TRI.  In the tea manufacturing process, the cost of energy is a major portion.  As such, increasing the energy efficiency of the manufacturing process without adversely affecting the quality of made tea has been a major theme of research in the Process Technology Division of the TRI, which has developed and introduced automation and optimiaation procedures for certain steps in the process such as withering and drying.

Recent introduction of high input-high return tea growing systems such as high-density planting is an option which has the potential to achieve substantial productivity increases at increased input use efficiency.  This system using a high level of modern technology such as fertigation, higher generation fertilisers and AI-assisted automation.  The TRI has initiated a collaborative research programme with the practitioners of high-density planting systems and their input suppliers to assess the long-term sustainability of such high input-high return systems.

While the labour cost makes up a major portion of the COP, efficiency of labour in Sri Lankan plantations is low in comparison to other tea-producing countries such as Kenya and India, which also employ manual labour.  For example, the daily plucking norm for a plucker in Sri Lanka is 20 kilos per day whereas in India and Kenya it is around 30-35 kilos per day.  Therefore, there is a need for measures to increase labour efficiency in the tea sector.  Linking the wage increases to increased work efficiency is one such strategy.

Need for consistency of government policies

During the past decade, the tea sector has been hit hard by short-sighted and ill-advised changes in government policy.  In 2015, the ban on glyphosate, which is one of the few herbicides available to the tea industry, set it back significantly and according to TRI estimates caused a 30% loss of production.  The weed control of tea plantations has not fully recovered from the glyphosate ban yet.  When the industry was coming out the glyphosate ban, came the ‘100% organic agriculture overnight’ drive in 2021.  The ensuing reduction in the application of fertiliser contributed significantly to the production decline that continued up to 2023 until the trend was reversed in 2024.  However, the bushes may not have recovered fully from the debilitation that occurred due to inadequate application of fertilizer, which has increased their susceptibility to stresses such as drought, pests and diseases.

The need to make the tea industry climate resilient

Climate change is a universal threat to all aspects of society and particularly for agriculture.  Tea is a highly climate-sensitive crop. Increasing temperatures, especially in the low-country, where the current temperatures are at a higher level, makes the tea crops in the low-country especially vulnerable to heat stress and yield loss.  This has serious implications to the tea industry as the low-country contributes a major portion to Sri Lanka’s total tea production.  Even though the up-country currently is at a lower temperature regime, TRI’s research indicates that tea crops in the up-country, which are adapted to a cooler temperature regime, may be more sensitive to increasing temperatures than those in the low-country.  In addition to increasing temperatures, TRI’s research has demonstrated changes in the rainfall pattern and amounts in different tea growing regions, thus revealing the possibility of adverse impacts of both drought and excessively high rainfall on the productivity of tea crops.  In order to counter the adverse impacts of climate change, the TRI has incorporated different features of climate resilience such as drought and heat tolerance into its plant breeding programme.  In fact, some of the newly-introduced cultivars in the TRI 5000 Series have greater drought tolerance.  In addition to breeding climate resilient cultivars, the TRI has recommended a package of climate smart agricultural practices, which include proper maintenance of shade, irrigation, rainwater harvesting and soil organic matter management.

The future role of the Tea Research Institute of Sri Lanka

While celebrating the milestone of completing 100 years of service, it is important that the TRI assesses and predicts what the future holds and devises strategies to meet the current and future challenges. Science is advancing at an unprecedented pace generating a multitude of new technologies.  The best recent example is the emergence of artificial intelligence and its expanding applications in almost all facets of life, including research and development.  The last few decades saw the emergence of new disciplines such as biotechnology, nanotechnology and mechatronics which have provided innovations to develop products of greater quality with greater efficiency.  The TRI is facing the challenge of upgrading and modernising its research infrastructure while recruiting the best available talent to engage in cutting edge research so that emerging technology advances can be harnessed to maintain the competitive edge of Ceylon tea.  The TRI should be equipped with state-of-the art laboratories having modern equipment.  At the same time, the TRI should be able to attract the cream of the graduates from universities and top professionals from the industry to carry out its R & D activities.  This necessitates a significant shift in the TRI’s mode of operation and its mode of governance.

A greater portion of the foreign exchange revenue from tea sales should be channeled back to upgrade the infrastructure for R & D at the TRI.  For most part of the existence of the TRI, proceeds from the tea ‘cess’, which was levied from each kilo of tea exported, was available for infrastructure and human resource development at the TRI.  However, this changed during the first decade of the new millennium so that the ‘cess’ was absorbed to the treasury and the TRI has had to depend on government allocations from the consolidated funds.  This mechanism may have its merits.  However, it is only fair that the ‘cess’ from the proceeds of tea exports is channeled back to address the specific needs of the TRI and strengthen its capacity to address the needs of the tea industry.

The remuneration package offered to the TRI scientists should be increased substantially so that the TRI can attract the best talent that is available and retain it in the institute.  During the past two decades, the TRI has lost several competent scientists to overseas R & D institutions and local universities, which offer a much higher remuneration package for personnel with similar qualifications.  Therefore, out-of-the-box thinking and strategies are needed to maintain the TRI as a modern R & D institute to meet the needs of a rapidly modernising industry and trade.  One such strategy is to implement changes in the mode of operation of the TRI by converting it to a research, development and higher education institution.  Even in its present state, the research infrastructure available at the TRI is superior to that available in most Sri Lankan universities.  Therefore, the TRI is ideally positioned to be incorporated into the network of institutions that are mandated to offer higher degrees by research.  There are research institutions elsewhere in the world which operate concurrently as both R & D institutions and degree awarding institutions.  The Indian Agricultural Research Institute (IARI) in New Delhi, the network of Indian Institutes of Technologies (IITs) and the network of Max Planck Institutes in Germany operate in a similar mode.  By operating on such a model, the TRI will be able to attract a set of young and talented graduates who would carry out industry-relevant research leading to higher degrees (PhD and MPhil), while offering a remuneration package to its scientists, which is on par with that of the university academics.  As such, harnessing the infrastructure and research expertise available at R & D institutions such as the TRI to train a young generation of scientists at the higher degree level will be a win-win situation for the country and its people.  Such a step will enable the TRI to transform itself to an operational and governance mode that will upgrade it to a modern institute catering to multiple needs while serving the Sri Lankan tea industry for it to remain competitive.

The author  (janendrad@gmail.com) acknowledges the information provided by Dr. H.W. Shyamalie, Principal Research Officer and Head of Agricultural Economics Division of the TRI and Dr. Mahasen Ranatunga, Director, Tea Research Institute.  Most ideas and strategies discussed in this article are the result of many fruitful discussions that took place over the last two decades during deliberations of different sub-committees of the TRI and in meetings of the Tea Research Board during the past year.

by Professor Janendra De Costa
Chairman, Tea Research Board
(Part I of this article appeared in The Island yesterday (10 Nov.)