Coconut coir: Not just a beautiful doormat

Abstract

Coconut is one of the most versatile fruits with amazing medicinal properties and astonishing health benefits. Even the coconut coir is extensively used for making doormats, decorative items and in upholstery industry. No wonder coconut palm is called the ‘tree of life’. More recently, remarkable applications of coconut coir and coir dust in diverse fields are emerging.

Full text

CORRESPONDENCE
CURRENT SCIENCE, VOL. 104, NO. 8, 25 APRIL 2013 995
Coconut coir: not just a beautiful doormat
Coconut is one of the most versatile
fruits with amazing medicinal properties
and astonishing health benefits. Even the
coconut coir is extensively used for mak-
ing doormats, decorative items and in
upholstery industry. No wonder coconut
palm is called the ‘tree of life’. More
recently, remarkable applications of
coconut coir and coir dust in diverse
fields are emerging.
Coir dust and biochar obtained from
coconut fibre serve as a good peat substi-
tute1,2. Biochar, a carbon-rich material
that is porous with oxygen functional
groups and aromatic surfaces is obtained
from thermal degradation of organic
materials such as crop residue, forest
residue, wood, manure and other materi-
als. Moreover, biochar locks up rapidly
decomposing carbon in plant biomass in
soils for hundreds or thousands of years.
It improves the structure and fertility of
soils, thereby improving biomass produc-
tion. It not only enhances the retention
and thus efficiency of fertilizers but also
decreases fertilizer run-off3. Besides,
coir pith has been found to harbour use-
ful microorganisms with potential use as
plant nutrient, including nitrogen-fixing
bacteria4.
A wide variety of heavy metals and
organic chemicals originating from indu-
strial effluents are potentially toxic,
owing to their detrimental effects to
humans and other living organisms. One
of the promising remedies for their
removal is using coconut coir pith, espe-
cially in the form of biochar for adsorp-
tion technology. In spite of proven
efficacy of activated carbon as an
adsorbent for metal removal, its high
cost has restricted its pervasive use. Due
to high surface-to-volume ratio and sub-
stances inherently associated with cellu-
lose such as lignin, tannin and pectin,
which contain polyphenolic and aliphatic
hydroxyl and carboxylic groups, biochar
can be a potential sorbent for heavy
metals as well as organic pollutants, par-
ticularly planar aromatic compounds.
Lignocellulosic biomass obtained from
coconut is an attractive precursor for
biochar preparation, as it shows high
porosity. Coir-based biochars manifest as
cost-effective scavengers for chromium
(VI), mercury (II), etc.5,6. On the other
hand, different chemical activating
agents can be used for improving the
adsorption properties of these carbons
and they include KOH, ZnCl2, H2SO4,
H3PO4 and HNO3.
In the construction sector, eco-
efficient materials obtained from coconut
coir can innovatively substitute some
traditional construction materials like
particleboards having applications as in-
sulating ceiling and walls. Consequently,
wax can be added to composite boards to
increase the resistance to absorption of
liquid water. In order to improve physi-
cal and mechanical properties of these
panels, adhesives like castor oil-based
polyurethane, urea formaldehyde, phenol
formaldehyde and isocyanate can be
used. Using such panels with low thermal
conductivity will decrease the energy con-
sumption of building facilities (air-con-
dition), since they reduce heat transfer
into space7,8. Also, coir dust extract acts
as a good corrosion inhibitor for acid-
induced corrosion of aluminium via
adsorption of the extract components on
the metal surface through the functional
groups present on the extract. Its inhibi-
tion efficiency increases with increase in
extract concentration and with tempera-
ture9.
1. Abad, M., Noguera, P., Puchades, R., Ma-
quieira, A. and Noguera, V., Bioresour.
Technol., 2002, 82, 241–245.
2. Tian, Y., Sun, X., Li, S., Wang, H., Wang,
L., Cao, J. and Zhang, L., Sci. Hortic.,
2012, 143, 15–18.
3. Lehmann, J., Nature, 2007, 447, 143–144.
4. Reghuvaran, A., Jacob, K. K. and Ravin-
dranath, A. D., Afr. J. Biotechnol., 2012,
11, 7063–7071.
5. Shen, Y., Wang, S., Tzou, Y., Yan, Y. and
Kuan, W., Bioresour. Technol., 2012, 104,
165–172.
6. Anirudhan, T. S., Divya, L. and Rama-
chandran, M., J. Hazard. Mater., 2008,
157, 620–627.
7. Khedari, J., Charoenvai, S. and Hirunlabh,
J., Build. Environ., 2003, 38, 435–441.
8. Fiorelli, J., Curtolo, D. D., Barrero, N. G.,
Savastano Jr, H., Pallone, E. M. J. A. and
Johnson, R., Ind. Crops Prod., 2012, 40,
69–75.
9. Umoren, S. A., Eduok, U. M., Israel, A.
U., Obot, I. B. and Solomon, M. M., Green
Chem. Lett. Rev., 2012, 5, 1–11.
SWATI MAHENDRU
Nucleic Acids Research Lab,
Department of Chemistry,
University of Delhi,
Delhi 110 007, India
e-mail: swati.chemistry@gmail.com
Denuded type locality of endangered dwarf grass Isachne mysorensis
Sundararagh. – its reoccurrence in western Karnataka
The members of Poaceae constitute one
of the most fascinating groups of flower-
ing plants with wide, ubiquitous distribu-
tion and immense diversity. The tropical
and subtropical genus Isachne R. Br. has
maximum representation in India, with
32 species out of 106–115 species dis-
tributed worldwide1–4. Of these, 21 spe-
cies are endemic to India, suggesting this
as the probable centre of proliferation,
diversification and evolution of the genus.
The species Isachne mysorensis Sundara-
ragh. is an amazing, curious, miniature
grass endemic to western Karnataka. It
grows in moist, rocky crevices on gentle
slopes, in association with Canscora
spp., Hedyotis spp., Impatiens spp., Lin-
dernia spp., Murdannia spp., Neanotis
spp. and Utricularia spp. Measuring 4–
8 cm, it is the smallest of all Isachne spe-
cies (12–200 cm).
The only report5 of the occurrence of
I. mysorensis was from the type locality
in Kundadagudda near Agumbe, Shi-
moga district, Karnataka. Lacuna existed
in further scientific research on the spe-
cies, which prompted the present lead

CORRESPONDENCE
CURRENT SCIENCE, VOL. 104, NO. 8, 25 APRIL 2013
996
author to survey and study the type local-
ity in 2006 and for five consecutive years
till 2011, during the flowering and fruit-
ing season (August–September), for
fresh collections. However, it was noti-
ced that there were no more individuals
extant and the type locality was com-
pletely denuded. This was due to severe
anthropogenic disturbances, such as
clearing of the natural forest for deve-
lopment of picnic spots, grazing and cut-
ting of roads, etc. As a result, the type
locality got transformed into bare grass-
land with a dearth of rocks and rivulets
that serve as natural habitat of the grass,
and eventually its extinction in wild.
During the extensive floristic surveys,
the authors inadvertently embarked upon
a dwarf grass specimen from Kollur
forest, near Souparnika River, in Moo-
kambika Wildlife Sanctuary, Udupi dis-
trict, Karnataka (13°42′–13°59′N lat. and
74°39′–74°50′E long.). The detailed
morphological study and perusal of the
literature revealed this to be the poorly
Figure 1. Habit of Isachne mysorensis
Sundararagh.
known species I. mysorensis Sundara-
ragh., strictly endemic to Karnataka. Its
miniature size, concealed habitat within
the fine rock crevices and broad ovate–
chordate leaves were diagnostic charac-
ters (Figure 1). Embedded in the forest
on the western edge of the Western
Ghats, which comprises nine districts of
Karnataka and six of Maharashtra, the
current population is the only extant
locality of the species as all other adjoin-
ing 15 districts were thoroughly surveyed
and found to be devoid of any other
population. The current population com-
prises 93 individuals occupying a small
area of c. 2 m2. The small population
amidst the natural forests of Kollur dis-
trict is also exposed to severe threats due
to anthropogenic disturbances such as
forest clearing for developmental
activities, grazing, setting fire for local
destruction of dry fallen leaves and
encroachment into the forest for broaden-
ing of roads, etc. A necessity for conser-
vation of I. mysorensis is now urgently
realized as it is already extinct in the
altered type locality, currently extant and
strictly endemic to the Kollur forest in
Mookambika Wildlife Sanctuary. Hence
this forest pocket within the sanctuary
needs to be conserved as the natural
habitat of the otherwise extinct miniature
grass. Further, the narrow, restricted
population size (93 individuals) calls for
studies on reproductive biology with the
aim of its multiplication under ex situ
conditions and rehabilitation in the wild.
The new locality reported here is almost
adjacent to the type locality, which could
possibly be within the normal seed dis-
persal range of the grass in the forest. It
is also probable that the current popula-
tion existed even when the type locality
was established, but went unnoticed as
the Mookambika Wildlife Sanctuary
remained taxonomically unexplored. The
prospects of this locality being an exten-
sion of the type locality or vice versa,
through two-way normal seed dispersal
distance, cannot be ruled out. But under
the present scenario, as the species has
become extinct in the altered original
type locality, the Mookambika Wildlife
Sanctuary is the only extant locality of
I. mysorensis, now categorized as criti-
cally endangered on the basis of critical
population estimates.
1. Bor, N. L., The Grasses of Burma, Ceylon,
India and Pakistan, Pergamon Press,
Oxford, 1960, pp. 576–583.
2. Prakash, V. and Jain, S. K., Fasc. Fl.
India, 1984, 14, 1–37.
3. Prakash, V. and Jain, S. K., J. Indian Soc.
Bot., 1987, 66, 107–115.
4. Iskandar, E. A. P. and Veldkamp, J. F.,
Reinwardtia, 2004, 12, 159–179.
5. Raghavan, R. S., Indian For., 1971, 97,
304–307.
ACKNOWLEDGEMENTS. We thank Dr
P. Singh, Director, Botanical Survey of India
(BSI), Kolkata and Dr P. G. Diwakar, Ex-
Joint Director, BSI, Western Regional Centre,
Pune for providing facilities and encourage-
ment. We also thank the officers and staff of
the Mookambika Wildlife Sanctuary, Karna-
taka for help during the exploration.
R. KR. SINGH*
ARTI GARG
Botanical Survey of India,
Central Regional Centre,
Allahabad 211 002, India
*e-mail: rksbsiadsingh@yahoo.co.in
River Sarasvati
Giosan et al.1, while commenting on
Valdiya’s article2, point out that sen-
tences from another source have been
misattributed to them by Valdiya. I want
to clarify that I am the author of those
sentences. Those sentences are from my
blog post3 on Harappan fluvial history
published on 15 June 2012. I alone am
responsible for them and that I have
no connection with Giosan or his co-
authors. Valdiya identifies S. Kalyana-
raman, an active contributor to the ‘India
Archaeology’ forum, as his source of
these sentences.
Taken in isolation these sentences may
be construed as a criticism by me of all
Indian geologists working on the Sara-
swati/Ghaggar river. On the contrary, my
blog posts4 on this issue have highlighted
the work of Indian geologists studying
this problem. Valdiya stresses2 that hun-
dreds of Indian geologists have been
working on this problem for over 50
years. It is important to clarify that
not all of them agree with Validya’s
conclusions about the presence of a gla-
cial Saraswati during Harappan times.
Valdiya cannot speak for them or other
independent studies, but he keeps using
the words ‘our conclusions’ and ‘we’. It
appears that he has assumed the respon-
sibility of speaking for all Indian geolo-
gists.
For example, Saini et al.5 in their arti-
cle on fluvial activity in Haryana do not
speculate that sediments were deposited