Climatic chaos and vanishing potatoes
Palitha Wijethunga: Increase in
temperature good for potato cultivation
There are no cascading waterfalls among the dark green hills; or does
any glittering stream carry crystal cold water. During January-March dry
season much of the beautiful harmony of nature has been carried away
with the time; however, it was not so even during dry seasons two or
three decades ago. Instead, there was the hum of some hundreds of water
pumps echoing among the hills; misty dark greenery was replaced with
hundreds of brown coloured terraced vegetables fields, one upon the
other on the steep hills.
This is Nuwara Eliya, the country's famous cool capital, known as
Little England, is also the country's potato capital since the country's
best potatoes are produced here. It is a matter of some more decades
before the crop is doomed in the cool climes as Nuwara Eliya is getting
hot! Future generations would not be so fortunate as to taste crunchy,
crispy, Nuwara Eliya potatoes!
Of course, Nuwara Eliya is getting hot, simply every one feels it,
residents, visitors and so do the scientists! According to the
Meteorological Department statistics, each passing year the minimum
night time temperature in Nuwara Eliya increases by 0.025 degrees and
the temperature in Nuwara Eliya will increase by 2.5 degrees during the
next century! "By then, potatoes could not be grown in Sri Lanka,"
warned Dr. Punyawardane, Head, Agro-Climatology Unit, Agricultural
D.M.S. Sunil:Potato should not be
cultivated in Nuwara Eliya
"You can grow potatoes in Kandy, but without any tubers, it would be
just an ornamental plant, here," he commented. He explained that there
should be a difference of eight degrees between the day time maximum and
the night time minimum temperatures to grow potatoes and it is less than
eight in Kandy; however, which is around ten in Nuwara Eliya, he said.
"The more the difference the better the potatoes," he said.
He said that the temperature gap is gradually narrowing down in
Nuwara Eliya at an alarming rate of 0.025 degrees per year. "As a result
the potatoes would be smaller, number of potatoes per plant would be
less and it would not be crispier," he noted.
"The reduction in the yield could be partially due to the increase in
the temperature," expressed Dr. Punyawardane, due to this significant
annual increment in the temperature, which is the highest in the
country. He added that the high soil erosion and poor quality seeds
contributed to drastically reduce the yield. The crop was first
introduced in the country in the 1950s and the harvest then had been
twentyfold, he said.
Downpour and higher temperature
Palitha Wijethunga (41), Vijayabhapura, Kandapola, cultivated around
one acre of potatoes for 20 years also has evidence that the climate in
Nuwara Eliya, has changed. "North-East Monsoons may come 1-2 months
early or late." He recollected that the continuous showers the Monsoon
had been replaced by heavy downpour for a few hours and longer
consecutive dry periods. "Now it's changed. Sometimes it would rain for
a week and sometimes not at all and there would be sudden downpours
which would destroy cultivation," he explained how the weather in the
highlands had changed. "We have not had a proper rainy season since mid
December last year."He pointed out that the temperature in Nuwara Eliya
too had gone up.January and February supposed to be the coldest months
of the year, was not cold as before. "Look, now people do not wear warm
clothes. I am wearing just a shirt," he elaborated.
Poor quality seeds
Along with those changes in the climate, the crop yield too has come
down. "Definitely, there is a reduction in the yield," however, he said
that there were some other contributory factors, such as the use of the
poor quality seed potatoes had affected the yield.
"The more the rain, more are the diseases, that attack the potato
D.M.S. Sunil of Lady McCullum Drive, Nuwara Eliya said if the climate
is good he could fetch a good harvest of 500kg of potatoes from 50kg of
seed potatoes. Usually, the average amount was around 300-400kg.Drought
is worse than 5-6 years ago and the yield is poor. Rain is less but
there is a lot of "Akal Wehi," untimely rains which are not expected
that would erode fertile top soil and destroy vegetable plants.Nuwara
Eliya is a mountainous terrain, therefore, growers should level the
steep slopes for the cultivation; these are narrow bed upon bed as you
see it from a distance.
These terraced fields are quite vulnerable to heavy rains. A kilogram
of potato was sold at Rs. 60 over 15 years ago, when one a kilogram of
rice was just around 10-20 rupees. Now a kilo of rice and potatoes are
sold at Rs. 60. He said that Indian Potatoes are available in the heart
of country's potato production districts may be for the first
time."People do buy them because they are cheaper."
He pointed out that drastic consequence of the climate change that
occurs in Nuwara Eliya area, which is an important water shed of the
Mahaweli river, the country's longest river, key to the electricity
generation and the agriculture in the dry zone. "One of the reasons for
the implementation of the Mahaweli Project was that the river carried a
substantial amount of water even during a drought.
P.A. Appuhamy Senarathne: Fears
But there was only a little water in the reservoirs down stream as
virtually thousand water pumps sprayed water out of streams that fed the
river and vaporize it into the cold dry air.
Not a single stream carried water down stream during the dry
season.There was a dearth of water in areas such as Welimada and Kotmale
which lie below Nuwara Eliya.
No wonder the reservoirs downstream lacked water he explained.He
believed that ideally the potato cultivation should be stopped in Nuwara
If one is concerned of the country's future and only a few would lose
their livelihood, but the country would conserve its vital life blood.
After all, the cultivation has not contributed much to the development
of the area.
P.A.Appuhamy Senarathne (72) of Magoda, Ruwaneliya, said the
unbearable cold when he first settled in 1972 has been considerably
changed and that he only needs a shirt during the day time.
But even I was young I had to put on number of clothes.
A plot being prepared
for potato cultivation.
"The people just left lands granted by the government because it was
so cold." This year we had ground frost even in December, which we
usually have in January-February and the dry period is longer than usual
and from last December we did not have rain.
The wells were dried and people do not have water even for drinking.
"This could be first time that wells ran dry.
We never had such a drought before.Nuwara Eliya water was just like
crystals, we used to drink water from streams, which are now polluted,
He too agrees that the potato yield is poor due to number of reasons;
that seeds are of poor quality, poor soil which is not fertile because
of decades of erosion.
Also the higher cost of fertiliser makes people use less fertilizer.
He also alleged that the agricultural officers never visited their
cultivations.Would climate change and global warming, change the future
of potatoes in Sri Lanka?
(This article was written under the aegis of CSE Media Fellowships)
Butterflies, charming but self-armed!
Everyone, young or old, likes butterflies and is enchanted by their
presence. But how many of them know that some butterflies are perfumed
and smell of verbena, lemon or pineapple or that some butterflies have
evolved protective coloration or resort to rues against the attacks by
predators? Have you ever heard of the butterflies which in their larval
stage cohabit with the ants being tended by them in their nests or of
larvae showing cannibalistic tendencies.
Well, these are some of the aspects in the interesting life history
of the "Scaly-winged Tribe" that should make the study of butterflies
more alluring than simply observing them in the field and feasting one's
eyes on their beauty.
Once, some years ago, I observed a Common Mime or Lankeswara
butterfly hovering about a cinnamon shrub in the garden. I went down
with my magnifying glass in hand to investigate. A closer look revealed
that it had laid half a dozen tiny, yellowish-green eggs on tender
leaves and the stem I collected from two of the eggs placed in an empty
jam bottle with a tight-fitting stopper.
I examined the eggs every night in the light of my table lamp and on
the forth day they hatched and the larvae started to eat the egg shells,
their first meal. The new-born larva was spiny and dark-brown in colour
with the centre of body buff-white. At first the larvae relished the
tender cinnamon leaves but later on they switched to a diet of the
leaves of Litsea longifolia "Ratkeliya" which I offered them. The
half-grown larva was brown and ochreous with greasy-looking marks and
looked exactly like a bird's dropping. Perhaps, in the wild it would
have been probably overlooked by an enemy owing to its resemblance to an
inedible object. When the larva was nearly full-grown it assumed a
coloration of gaudy black, yellow and red, which the entomologists
describe as a "Warning coloration" usually seen among insects with
poisonous or repellent features that repulse the enemies from attacking
On the 13th day after hatching from eggs, both the larvae stopped
feeding and got ready to pupate on the sticks I provided for them. The
next day the changeover was completed round about 11 in the night, a
process which took them almost thirty hours.
On pupation the larva retuned to the device of resembling an inedible
object once again, but this time it assumed the form of a short,
snapped-off dead twig; the base of the pupa being so shaped that it
appeared to have grown out of the stick to which it was anchored. The
pupa as a whole was brown to dark brown in colour with pencil marks of a
lighter shade and measured 39 mm. by 8 mm. The adult butterfly emerged
14 days late.
Experiments on the metamorphosis of the Common Mime Chilasa clytia
lankeswara butterfly point to the fact that when the adult butterfly
emerges, whatever its sex, whether it was the typical brown form or the
striped black and blue dissimilar form, it mimics three butterflies of
the Euploeas family and three of the Danaus species. The butterflies of
both these groups are known to be distasteful to the birds and their
colour schemes are of the warning type.
It is presumed that the two colour forms of the Common Mime take
advantage in the protection conferred by this warning coloration. This
is further advanced by the fact that both forms have two distinct styles
of flight-one, used when they are alarmed or pursued by an enemy, in the
ordinary, swift and dodging flight of the Swallow-tail family to which
it belongs, the other is the slow, sailing, careless style of flight
always used by both the Euploea and Danaus groups of butterflies. The
second is the style adopted while feeding and playing and especially, by
the female, while laying her eggs. Under these circumstances, it is
hardly possible to distinguish between the mimic and its models in the
field, even for a trained observer.
However, no direct observations appear to be on record to indicate
whether the Common Mime possesses poisonous or repellent qualities
rendering it unedible to its natural enemies or whether these qualities
fluctuate in agreement with the changes in its life history, between the
two types of coloration.
It has been found that beyond being very tenacious of life all
butterflies of the Danaid species, i.e. Tree Nymp, Glassy Tiger, Blue
Tiger, Blue Glassy Tiger, Dark-blue Tiger, Common Tiger and Common
Indian Crow, Double-banded Crow, Great Crow and King Crow and three of
the Papilio group i.e. Ceylon Rose, Crimson Rose and Common Rose are
protected by the possession of unpalatable body juices, because in their
larval stage they feed on poisonous plants, hence once an enemy has
tried to eat anyone of them it will have either died or will never try
again. The colouring patterns in such cases are usually so conspicuous
that the enemy is pre-warned not to attack.
The protective devices occur not only in the adult stage but also in
the larval and pupal stages. The larva is frequently coloured to
harmonize with the surroundings, it may be armed with spines or possess
threatening markings, which together with definite gestures, give it
superficially a terrifying look. Others who are brightly coloured, and
fed by day and exposed to view possess distasteful qualities and exhibit
warning patterns as the adult butterflies do. On the other hand, the
larvae who are supposed to be palatable escape detection by hiding
during daylight hours and venturing out to feed at night.
The larvae of certain butterflies of the Lycaenidae family have
evolved a curious system of protection in conjunction with ants. The
ants tend and protect the larvae and receive in return sweet juices
which are emitted from glands of the larvae. In certain cases the larva
when nearly full grown is taken away by the ants to their nests where it
is fed and looked after until it pupates at leisure and emerges from the
nest as a full-fledged butterfly in due course.The Lycaenidae are a
large family in Sri Lanka mostly of small sized butterflies, consisting
of 81 species.
The larvae of this species possess specialized organs that are known
to exude a sweet fluid much relished by ants.
The Apefly butterfly Spalgis epeus epeus of this family apart from
its normal diet of vegetable is known to feed in its larval stage on
Mealy Bugs or small insects, but displays a strong tendency towards
cannibalism, occasionally eating brethren of the same brood.
Sometimes, a larva which in its early stage feeds on flowers and
plants may later wonders away and meets an ant, which is attracted by
the sweet honey like fluid the larva exudes. The ant moves the small
larva to its nest where from being a vegetarian the larva turns
carnivorous, feeding for the rest of its larval life on the young of the
ants, until it is ready to pupate.
In other cases it is believed the female butterfly lays her eggs in
close proximity to an ant's nest and after the tiny larvae hatch out
they are taken by the ants into the nest and treated somewhat on the
lines the humans treat milch cows.
Another interesting feature in this widespread family is that the
male butterflies of some species possess either scent pouches or patches
of specialized scent-producing scales on their wings. The glandular
cells which contain the scent secrete a volatile fluid or essence which
in certain circumstances flows into the scales and eventually passes off
by evaporation as an odorous vapour...
There is evidence to believe that scent-producing structures are the
exclusive property of the male butterflies, hence we may feel pretty
certain that their chief function is to charm or attract members of the
opposite sex at the time of courtship. That these perfumed male insects
are really irresistible to the females of their kind has been proved
again and again by interested observers of insect-life in many
With some species the scent tufts emit a strong perfume not unlike
that of pineapple, while the scent scales of some others are known to
give forth a fragrance which has been likened to that of the lemon
Meanwhile, many kinds of butterflies and moths often notable for
their gaudy coloration give out disgusting smells, especially if they
are alarmed or touched.
Family: - Asclepiadaceae
Scientific Name:- Brachystelma lankana
Dassanayake & Jayasuriya.
Sinhalese Name:- Pathan-ala
Status:- Critically Endangerd, Endemic
* Brachystelma lankana highly restricted to Knuckles region
(Endemic), belongs to Asclepiadaceae family, with only one species is
recorded from Sri Lanka.
* It is a small herb simple stem or with a few branches. Consisting
one tuber underground, with small leaves tapering at both ends and
laceolate in shape.
* Small flowers have lobed petals. Fruits are long and elongated.
* According to the 2007 Red List of Threatened Fauna and Flora of Sri
Lanka Patan-ala is critically endangered species. It was protected under
the Flora and Fauna Protection Ordinance. This species will be extinct
due to over collection, habitat destruction, etc...
1.Dassanayake, M.D. and Fosberg, F.R.(eds.)(1983) A revised handbook
to the flora of Ceylon. Amerind, New Delhi.
2. IUCN Sri Lanka and the Ministry of Environment and Natural
Resources (2007)The 2007 Red List of Threatened Fauna and Flora of Sri
Lanka, Colombo, Sri Lanka.
Pic and text: Dilup Chandranimal
IUCN (The International Union for
Conservation of Nature)
Sri Lanka-Country Office