Department of Studies in Biochemistry, Mangalore University, India
Submission: September 12, 2017; Published: October 13, 2017
*Corresponding author: Manjula Shantaram, Department of Studies in Biochemistry, Mangalore University, India.
How to cite this article: Ashwini S, Suresh BTV, Varun K SM, Kshama K, Naveen K KB, Manjula S. Studies on Pharmacognostical and Biochemical Constituents of Selected Seaweeds and Their Effects as Liquid Fertilizers on Growth of Crop Plants. Glob J Pharmaceu Sci. 2017; 3(4): 555618. DOI: 10.19080/GJPPS.2018.03.555618.
The effect of Seaweed Liquid Fertilizer (SLF) of three seaweeds was tested at different concentrations (10%, 20%, 40%, and 60%)on growth parameters of Allium cepa (onion), Solanum melongena (brinjal), Eleusinecoracana (ragi), Oryza sativa (paddy), Solanum lycopersicum (tomato).Seaweed extracts at different concentration were used to find out their efficiency on germination of seeds and plant growth inhibiting (toxic) concentration. This study revealed that the 40% level of SLF enhances the growth and yield than other concentrations. Thus in the present study, the effect of seaweed extract on plant germination is being discussed and the future perspective of its usage as a bio-fertilizer can be encouraged.
The usage of seaweeds in agricultural land as a manure is very antique and common practice in several countries. Use of seaweeds as a fertilizer in the production of crop has an extended practice in coastal areas throughout the world. The seaweeds are known to possess several trace elements and growth hormones which are necessary for growth of plants. Seaweed manure was reported to comprise of nitrogen, potassium, and phosphorus.
Marine algal seaweed species are often regarded as an under-represented bio resource. The benefits of seaweeds as sources of organic matter and fertilizer nutrients have led to their use as soil conditioners for centuries [1,2]. Numerous studies have revealed a wide range of beneficial effects of seaweed extract applications on plants, such as early seed germination and establishment, improved performance and yield, elevated resistance to biotic and abiotic stress, and enhanced post-harvest shelf-life of perishable products [3,4]. Bokil et al.  has reported seaweed extracts are bioactive at low concentrations (diluted as 1:1000 or more). Liquid extracts obtained from seaweeds are successfully used as foliar sprays for several crops . The growth enhancing potential of seaweeds might be attributed to the presence of macro and micronutrients .
Seaweed Liquid Fertilizer (SLF) is found to be highly potential compared to chemical fertilizers by current researches.
Thus seaweed extracts as liquid fertilizers have come in market is established in recent years . The favorable effect of seaweed extract application is a result of several components which works synergistically at various concentrations, even though the mode of action still remains indefinite. In this study, effect of three common seaweeds viz. Gracilariacorticata, Chaetomorpha antenna and Ulva fasciataas liquid fertilizer was established on crop plants.
In the present study, effect of three common seaweeds viz. Gracilariacorticata, Chaetomorpha antenna and Ulva fasciata were handpicked in between intertidal rocks of Surathkal beach, Karnataka, India (13 00`34.1” N lat. & 74 47`16.1” E long). The collected seaweed was botanically identified by Dr. C.R.K Reddy, CSIR- Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, India.
Fresh seaweeds were washed thoroughly to remove all the epiphytes and sand particles with tap water. They were shade-dried for five to nine days. The dried seaweeds were powdered using kitchen type blender; further they were used for the preparation of Seaweed Liquid Fertilizer (SLF). The
coarse powder was mixed with distilled water in the ratio of
1:20 (w/v). Boiled for 60 minutes and filtered through four
fold of white cloth. The filtrate was collected and stored. The
filtrate thus obtained is considered as 100% . Four different
concentrations of solutions such as 10%, 20%, 40%, and 60%
were prepared and used for the study.
The crop plants, selected for the present study were onion,
brinjal, ragi, paddy and tomato. The seeds were collected from
the Indian Institute of Horticultural Research, Bangalore,
Karnataka. The seeds with uniform size, color and weight were
chosen for the experimental purpose and thoroughly washed
with distilled water 3-5 times.
Seeds of Allium cepa (onion), Solanum melongena (brinjal),
Eleusinecoracana (ragi),Oryza sativa (paddy), Solanum
lycopersicum (tomato) were treated with 3 different seaweed
liquid fertilizers as described elsewhere . Petri plates were
sterilized to avoid spoilage of seeds, and then filter paper was
placed to provide support and hold moisture for the germination
of seeds. Each plate was placed with three seeds of A.cepa, S.
lycopersicum respectively. Four different concentrations (10,
20, 40 and 60) of seaweed liquid fertilizer were poured on
each plate with respect to the seaweed and seeds. The seeds
were placed over filter paper and then, these were incubated
at room temperature. The plates were kept separately with
12 hours of dark and 12 hours of light. Also field study was
carried out using A.cepa, S. melongena, E. coracana, O. sativa, S.
lycopersicum. The seeds were monitored for germination after
three days and the growth of the seedlings were observed after
a period of fourteen days from the day of treatment. After the
observation of germination and growth of seedlings in the plate
and the seedlings in field which were treated with different
concentration of liquid fertilizers, various parameters such as
number of leaves, height of the shoot, length of the root, number
of lateral roots were measured. A plate with water instead of
liquid fertilizer was kept as control.
Growth of shoot was influenced by all the concentrations of
G. corticata, C. antenna and U. fasciata extracts and a maximum
value was recorded for 20%, 40% and 60% respectively. Among
the field study of three seaweed liquid fertilizers, G. corticata
liquid fertilizer yielded better results compared to other two
seaweeds. Temple has reported  increase in the harvest
of bean by seaweed foliar applications, whose average yield
was increased by 25%. Csizinszky has reported  staked
tomato yields increase by 99%. The presence of macro and
micronutrients and also some growth promoting substances
might lead to enhancing the growth potential of seaweed
extracts [13,14]. Whap ham et al.  has reported to increase
in chlorophyll of cucumber seedlings and tomato plants with
application of seaweed (Ascophyllumnodosum).
In normal visible light, different colors were observed in the
reaction of different chemical substances with fine powder of
G. corticata, C. antenna and U. fasciata the results of which are
tabulated (Table 1). The carbon, hydrogen and nitrogen content
of three seaweeds were determined, out of which C. antenna
showed highest carbon value, while hydrogen content was found
to be highest in G. corticata and U. fasciata was found to have
highest nitrogen content (Table 2).
In this study 60% of G. corticata,60% of C. antennina and 60%
of U. fasciata as liquid fertilizer have shown better yield for onion
(Table 3).In this study 20% of G. corticata, 20% of C. antennina
and 60% of U. fasciata as liquid fertilizer have shown better yield
for tomato (Table 4). In this study 60% of G. corticata, 40% of
C. antenna and20% of U. fasciata as liquid fertilizer have shown
better yield for brinjal (Table 5).In this study, 20% of G. corticata,
40% of C. antennina and60% of U. fasciata as liquid fertilizer
have shown better yield for paddy (Table 6).In this study, 20% of
G. corticata, 40% of C. antennina and60% of U. fasciata as liquid
fertilizer have shown better yield for ragi (Table 7).
This study also confirms that use of seaweed extracts as liquid
fertilizer was found to be highly effective in promoting growth;
it is a wise eco friendly technique to enhance crop production.
In this study, concentration of G. corticata as liquid fertilizer
showed best results. Seaweed extract which gave better results
at lower concentration shall be utilized at very high dilution rate
in agricultural field that can enhance the rate of germination of
seeds. It will not affect native useful microorganisms present in
soil and also seaweed as fertilizer is economical.
Authors would like to thank Mr. Yathish from ChikkaAluvara
village, Kodagu district, Karnataka, India for providing his plot
for the field study.