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Effects of
light colour and oscillator frequency on earthworm
bioactivity
Owa, S. O.*, Peters, S., Dedeke, G. A. and Aladesida, A.
Department of
Plant Science and Applied Zoology, Olabisi Onabanjo
University, Ago-Iwoye, Nigeria.
*Corresponding
author.
E-mail: stephenowa@yahoo.co.uk
.
Accepted 9 November, 2007 |
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An experiment was conducted at the Zoology Laboratory of the
Olabisi Onabanjo University, Nigeria to evaluate the
suitability of different light colours. Being generated from
15-watt, low-heat, or frequency-generated flourescent tubes
as stimulants to enhance, major cast productivity of the
earthworm species Hyperiodrilus africanus. The aim
was to determine if exposure to the different light colours
would improve the cast productivity of the worms and show
whether H. africanus would show preference for any
particular light colour, in terms of mass of cast produced
and rates of emigration. The earthworms were kept in
cylindrical plastic containers and put in different cubicles
on a wooden shelf, where they are subjected to different
light colours that is, white, dark (control), green, blue,
and red. Results indicated that the red light colour was the
most suitable in terms of cast productivity, as casting was
highest (11.96 g/worm), followed by blue (10.66 g/worm),
green (9.49 g/worm), dark (7.2 g/worm) and white (4.86
g/worm), respectively. Least emigration was recorded under
the control (dark) , followed by red, white, blue and green
respectively, which indicated that the worms were probably
more ‘comfortable’ in the dark and the red light than the
other light colours tested. Results suggest that if red
light is introduced to a farm, casting activities can be
increased and therefore, soil fertility can be improved.
Key words:
Cast productivity, different light colour, earthworm,
Hyperiodrilus
africanus |
