An experimental study was conducted to find out the effect of Blue light on Salvinia molesta. It was found that blue light enhances the vegetative growth under laboratory conditions. Another experiment was performed to find out the effect of acoustical waves on the growth of Pterisvittata. It has been observed during experiment that this fern grows even in the area where exhaust fumes are emitted by generators. This fern was subjected to wave frequencies of 1000, 500, 420, 380 & 100 Hz under a photoperiod of 14/10 h (day/night). Maximum growth was recorded to be dependent on the medium composition and independent of sound application. Sound waves applied during the dark period had no significant effect.
Key words: Blue light, Salvinia molesta, Pterisvittata L. Acoustical waves.

1. Introduction:
Light is of paramount importance for vegetative growth and other physiological processes. Light influences the growth at certain intensity duration and quality of light or wavelength. The visible light is a combined form of different colours (VIBGYOR). Each colour has different energy manifestation and wavelength. All seven colours of light cause voluptuous effect. The photomorphogenesis are directly related with quality of light. It is obvious that the various pigments present in the plant have specific requirements for light quality. Earlier it has been observed that red light is best for plant growth. But internodes show maximum increase in blue violet light. Phototropic movement is more in blue light (400nm – 510 nm). Other light waves also show effect.

Considering this it was decided to study the role of different monochromatic light on Salvinia molesta.. This plant grows luxuriantly in eastern region of Bihar and in Bengal planes. It is sometimes considered as abnoxious weer of aquatic medium hampering the movement in water and for cultivation of Euryale ferox and Traps bispinosa. Owing to this reason the effect of different monochromatic light and of ultraviolet and infra-red rays was experimented in laboratory conditions. Acoustical wave, if rhythmic normally leads happiness and joy. If it is beyond audible capacity it produces noise. In another investigation we have tried to study the effect of acoustical wave on the vegetative growth of pterisvittata. L. It is widely occuring leptosporangiate fern which shows voluptuous growth. It grows well in township area and resists to air pollution.
2. Materials and Methods:

Healthy plants from the field and growing in ponds and ditches at Motihari under cultivated conditions were collected and some plants were allowed to grow under normal condition (field) and in pteridology lab. under blue light condition with variable intensity and time duration.

Pterisvittata a common widely growing fern was subjected to experimentation. This fern starting from germination to adult (full grown plant) was treated with different wave frequencies (380 Hz, 420 Hz, 500 Hz, 1000 Hz) and changes were observed. P. Vittata L. was grown under Knop’s solution.

From Table 1, It is inferred that blue light enhances the internode length, leaf emergence from node, length of submerged leaf, diameter of submerged leaf, length of leaf, breadth of leaf and sporocarp. The number of sporocarp per submerged leaf remained the same. As compared to normal light the single blue light accelerates the vegetative growth to some extent. But when the exposure time is increased the rate of growth remained the same. It is obvious from Table 2 that Rhythmic music between 380 Hz to 500 Hz causes development and higher dose retard the growth and spore formation.

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(ii) Srivastava, R. B.: Observation on ferns of aquatic environment from Champaran. In syn. Vol. Towards understanding the Biology of pteridophytes ed. S.C. verma, Deptt. Of Botany Punj. Univ. Chandigarh, pp.33-34 (1984).
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