Opinion
A fungal disease threatens rubber cultivations in high rainfall areas
By Emeritus Professor Asoka Nugawela
(Former Director, Rubber Research Institute of Sri Lanka)
A new addition to the list of economically important diseases affecting natural rubber cultivations in the country is Circular Spot Leaf Disease (CLSD). It is also known as Pestalotiopsis Leaf Disease (PLD). This fungal disease was first reported in Sri Lanka in 2019 and by 2021 it had spread to around 20,000ha. Currently the affected extent is much higher. The disease severity is found to be more in rubber growing areas receiving a high annual rainfall with a higher number of wet days (Fig. 1). As per the rubber growers in such wet areas the new disease has caused around 30% loss in rubber production. Further the disease has also retarded the growth of young rubber plants. These situations are despite of the disease management programs undertaken incurring high costs. The rubber growers also fear that if this disease continues leading to secondary leaf fall the rubber plantations will become very weak leading to uneconomical rubber yields and poor growth rates in young rubber cultivations. Prolonged immature periods will result in high capital costs and lower the return on investments. At national level the rubber production will decline compelling the rubber product manufacturing sector of the country to import this raw material using scarce foreign exchange. The national rubber production has declined by nearly 6,000 MT from 2021 to 2022. The value of this production loss in 2022 is around 12 million US$.
Disease management
Based on research conducted by the Rubber Research Institute of Sri Lanka two of fungicides are currently recommended for the management of the disease. In the initial interim recommendation of the institute, the concentration of the fungicides is 3 g/ml per liter of water. Subsequently it was increased up to 5 and then again to 10 g/ml expecting to get a better control. In addition to the chemical control, the necessity to adhering into other important agronomic practices such as soil management, weed management, fertilizer application and harvesting is emphasized to enhance growth vigor and disease resistance of the trees.
High costs of the chemicals, spraying of the fungicides to cover the entire canopy of the tall rubber trees and continuous wet weather prevalent in traditional rubber growing areas are some constraints faced by the growers to adopt the chemical control of the disease. After application of the fungicides at least a 5-hour dry period is needed to prevent chemicals getting washed away.
Disease severity
It is clearly evident that since the first appearance of the disease in 2019, the disease severity has shown an increasing trend especially in the relatively more wet rubber growing areas. This is true in both young and mature rubber cultivations. Generally, in mature rubber the full quantum of leaves is present soon after re-foliation in March/April each year. Subsequently with the onset of monsoonal rains the disease incidence take place leading to leaf fall. Disease severity surveys undertaken by a particular plantation management company managing around 3,000 ha of mature rubber in the wetter region clearly shows the progression of the disease since its first detection (Table 1). Surveys had been undertaken in the month of December in each year prior to the onset of wintering.
Out of the total tapping blocks only 21% showed 76 to 100% secondary leaf fall by December 2020. However, in December 2022 this figure was 67%. Hence certain tapping blocks have shown more than 76% defoliation for three consecutive years which will invariably lead to the weaking of such trees leading to less growth and crop production. (See Table 1)
Impact on rubber production
The trend in land productivity of rubber plantations located in the relatively dry and wetter regions managed by this company reveal the impact of CLCD/PLD on the rubber production. Whilst the land productivity shows a gradual increasing trend in the relatively dry regions where the disease is not prevalent, it declines significantly in the wetter region. In both drier and wetter regions, the agricultural practices adopted are similar. Hence it is apparent that CLSD/PLD has led to around 30 to 35 % decline in rubber production in the disease affected areas (Table 2). This decline in rubber production could increase further in the coming years if the disease persists leading to secondary leaf fall. It should be stated that in the financial year 21/22 there were reasons other than CLSD/PLD to lower the land productivity. (See Table 2)
Interventions needed
As shown previously, the severity of the disease, is in an increasing trend since the initial year of infection. The significant negative impact on latex production and growth of young rubber plants are a serious threat to the sustainability of the rubber cultivations in the country, financial performance of investors/growers and the national economy. The potential consequences to the growers, investors and to the economy of the country is too significant for this issue challenging the industry to be taken lightly. Hence the government should be mindful of the consequences of this problem faced by the industry and extend its fullest corporation to the relevant government institutions and departments to come out with suitable a solution. The main strategies to be considered in combating this disease are chemical control methods which includes effective chemicals and application methods, identifying resistance varieties/clones, developing mixed cropping systems, agroecological zoning for crops and escaping from the disease by promoting growing of rubber in regions of the country where this disease is not prevalent to the extent to make rubber cultivations uneconomical.
Opinion
Buddhist insights into the extended mind thesis – Some observations
It is both an honour and a pleasure to address you on this occasion as we gather to celebrate International Philosophy Day. Established by UNESCO and supported by the United Nations, this day serves as a global reminder that philosophy is not merely an academic discipline confined to universities or scholarly journals. It is, rather, a critical human practice—one that enables societies to reflect upon themselves, to question inherited assumptions, and to navigate periods of intellectual, technological, and moral transformation.
In moments of rapid change, philosophy performs a particularly vital role. It slows us down. It invites us to ask not only how things work, but what they mean, why they matter, and how we ought to live. I therefore wish to begin by expressing my appreciation to UNESCO, the United Nations, and the organisers of this year’s programme for sustaining this tradition and for selecting a theme that invites sustained reflection on mind, consciousness, and human agency.
We inhabit a world increasingly shaped by artificial intelligence, neuroscience, cognitive science, and digital technologies. These developments are not neutral. They reshape how we think, how we communicate, how we remember, and even how we imagine ourselves. As machines simulate cognitive functions once thought uniquely human, we are compelled to ask foundational philosophical questions anew:
What is the mind? Where does thinking occur? Is cognition something enclosed within the brain, or does it arise through our bodily engagement with the world? And what does it mean to be an ethical and responsible agent in a technologically extended environment?
Sri Lanka’s Philosophical Inheritance
On a day such as this, it is especially appropriate to recall that Sri Lanka possesses a long and distinguished tradition of philosophical reflection. From early Buddhist scholasticism to modern comparative philosophy, Sri Lankan thinkers have consistently engaged questions concerning knowledge, consciousness, suffering, agency, and liberation.
Within this modern intellectual history, the University of Peradeniya occupies a unique place. It has served as a centre where Buddhist philosophy, Western thought, psychology, and logic have met in creative dialogue. Scholars such as T. R. V. Murti, K. N. Jayatilleke, Padmasiri de Silva, R. D. Gunaratne, and Sarathchandra did not merely interpret Buddhist texts; they brought them into conversation with global philosophy, thereby enriching both traditions.
It is within this intellectual lineage—and with deep respect for it—that I offer the reflections that follow.
Setting the Philosophical Problem
My topic today is “Embodied Cognition and Viññāṇasota: Buddhist Insights on the Extended Mind Thesis – Some Observations.” This is not a purely historical inquiry. It is an attempt to bring Buddhist philosophy into dialogue with some of the most pressing debates in contemporary philosophy of mind and cognitive science.
At the centre of these debates lies a deceptively simple question: Where is the mind?
For much of modern philosophy, the dominant answer was clear: the mind resides inside the head. Thinking was understood as an internal process, private and hidden, occurring within the boundaries of the skull. The body was often treated as a mere vessel, and the world as an external stage upon which cognition operated.
However, this picture has increasingly come under pressure.
The Extended Mind Thesis and the 4E Turn
One of the most influential challenges to this internalist model is the Extended Mind Thesis, proposed by Andy Clark and David Chalmers. Their argument is provocative but deceptively simple: if an external tool performs the same functional role as a cognitive process inside the brain, then it should be considered part of the mind itself.
From this insight emerges the now well-known 4E framework, according to which cognition is:
Embodied – shaped by the structure and capacities of the body
Embedded – situated within physical, social, and cultural environments
Enactive – constituted through action and interaction
Extended – distributed across tools, artefacts, and practices
This framework invites us to rethink the mind not as a thing, but as an activity—something we do, rather than something we have.
Earlier Western Challenges to Internalism
It is important to note that this critique of the “mind in the head” model did not begin with cognitive science. It has deep philosophical roots.
Ludwig Wittgenstein
famously warned philosophers against imagining thought as something occurring in a hidden inner space. Such metaphors, he suggested, mystify rather than clarify our understanding of mind.
Similarly, Franz Brentano’s notion of intentionality—his claim that all mental states are about something—shifted attention away from inner substances toward relational processes. This insight shaped Husserl’s phenomenology, where consciousness is always world-directed, and Freud’s psychoanalysis, where mental life is dynamic, conflicted, and socially embedded.
Together, these thinkers prepared the conceptual ground for a more process-oriented, relational understanding of mind.
Varela and the Enactive Turn
A decisive moment in this shift came with Francisco J. Varela, whose work on enactivism challenged computational models of mind. For Varela, cognition is not the passive representation of a pre-given world, but the active bringing forth of meaning through embodied engagement.
Cognition, on this view, arises from the dynamic coupling of organism and environment. Importantly, Varela explicitly acknowledged his intellectual debt to Buddhist philosophy, particularly its insights into impermanence, non-self, and dependent origination.
Buddhist Philosophy and the Minding Process
Buddhist thought offers a remarkably sophisticated account of mind—one that is non-substantialist, relational, and processual. Across its diverse traditions, we find a consistent emphasis on mind as dependently arisen, embodied through the six sense bases, and shaped by intention and contact.
Crucially, Buddhism does not speak of a static “mind-entity”. Instead, it employs metaphors of streams, flows, and continuities, suggesting a dynamic process unfolding in relation to conditions.
Key Buddhist Concepts for Contemporary Dialogue
Let me now highlight several Buddhist concepts that are particularly relevant to contemporary discussions of embodied and extended cognition.
The notion of prapañca, as elaborated by Bhikkhu Ñāṇananda, captures the mind’s tendency toward conceptual proliferation. Through naming, interpretation, and narrative construction, the mind extends itself, creating entire experiential worlds. This is not merely a linguistic process; it is an existential one.
The Abhidhamma concept of viññāṇasota, the stream of consciousness, rejects the idea of an inner mental core. Consciousness arises and ceases moment by moment, dependent on conditions—much like a river that has no fixed identity apart from its flow.
The Yogācāra doctrine of ālayaviññāṇa adds a further dimension, recognising deep-seated dispositions, habits, and affective tendencies accumulated through experience. This anticipates modern discussions of implicit cognition, embodied memory, and learned behaviour.
Finally, the Buddhist distinction between mindful and unmindful cognition reveals a layered model of mental life—one that resonates strongly with contemporary dual-process theories.
A Buddhist Cognitive Ecology
Taken together, these insights point toward a Buddhist cognitive ecology in which mind is not an inner object but a relational activity unfolding across body, world, history, and practice.
As the Buddha famously observed, “In this fathom-long body, with its perceptions and thoughts, I declare there is the world.” This is perhaps one of the earliest and most profound articulations of an embodied, enacted, and extended conception of mind.
Conclusion
The Extended Mind Thesis challenges the idea that the mind is confined within the skull. Buddhist philosophy goes further. It invites us to reconsider whether the mind was ever “inside” to begin with.
In an age shaped by artificial intelligence, cognitive technologies, and digital environments, this question is not merely theoretical. It is ethically urgent. How we understand mind shapes how we design technologies, structure societies, and conceive human responsibility.
Buddhist philosophy offers not only conceptual clarity but also ethical guidance—reminding us that cognition is inseparable from suffering, intention, and liberation.
Dr. Charitha Herath is a former Member of Parliament of Sri Lanka (2020–2024) and an academic philosopher. Prior to entering Parliament, he served as Professor (Chair) of Philosophy at the University of Peradeniya. He was Chairman of the Committee on Public Enterprises (COPE) from 2020 to 2022, playing a key role in parliamentary oversight of public finance and state institutions. Dr. Herath previously served as Secretary to the Ministry of Mass Media and Information (2013–2015) and is the Founder and Chair of Nexus Research Group, a platform for interdisciplinary research, policy dialogue, and public intellectual engagement.
He holds a BA from the University of Peradeniya (Sri Lanka), MA degrees from Sichuan University (China) and Ohio University (USA), and a PhD from the University of Kelaniya (Sri Lanka).
(This article has been adapted from the keynote address delivered
by Dr. Charitha Herath
at the International Philosophy Day Conference at the University of Peradeniya.)
Opinion
We do not want to be press-ganged
Reference ,the Indian High Commissioner’s recent comments ( The Island, 9th Jan. ) on strong India-Sri Lanka relationship and the assistance granted on recovering from the financial collapse of Sri Lanka and yet again for cyclone recovery., Sri Lankans should express their thanks to India for standing up as a friendly neighbour.
On the Defence Cooperation agreement, the Indian High Commissioner’s assertion was that there was nothing beyond that which had been included in the text. But, dear High Commissioner, we Sri Lankans have burnt our fingers when we signed agreements with the European nations who invaded our country; they took our leaders around the Mulberry bush and made our nation pay a very high price by controlling our destiny for hundreds of years. When the Opposition parties in the Parliament requested the Sri Lankan government to reveal the contents of the Defence agreements signed with India as per the prevalent common practice, the government’s strange response was that India did not want them disclosed.
Even the terms of the one-sided infamous Indo-Sri Lanka agreement, signed in 1987, were disclosed to the public.
Mr. High Commissioner, we are not satisfied with your reply as we are weak, economically, and unable to clearly understand your “India’s Neighbourhood First and Mahasagar policies” . We need the details of the defence agreements signed with our government, early.
RANJITH SOYSA
Opinion
When will we learn?
At every election—general or presidential—we do not truly vote, we simply outvote. We push out the incumbent and bring in another, whether recycled from the past or presented as “fresh.” The last time, we chose a newcomer who had spent years criticising others, conveniently ignoring the centuries of damage they inflicted during successive governments. Only now do we realise that governing is far more difficult than criticising.
There is a saying: “Even with elephants, you cannot bring back the wisdom that has passed.” But are we learning? Among our legislators, there have been individuals accused of murder, fraud, and countless illegal acts. True, the courts did not punish them—but are we so blind as to remain naive in the face of such allegations? These fraudsters and criminals, and any sane citizen living in this decade, cannot deny those realities.
Meanwhile, many of our compatriots abroad, living comfortably with their families, ignore these past crimes with blind devotion and campaign for different parties. For most of us, the wish during an election is not the welfare of the country, but simply to send our personal favourite to the council. The clearest example was the election of a teledrama actress—someone who did not even understand the Constitution—over experienced and honest politicians.
It is time to stop this bogus hero worship. Vote not for personalities, but for the country. Vote for integrity, for competence, and for the future we deserve.
Deshapriya Rajapaksha
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