Biogenic synthesis of zinc nanoparticles from Thevetia ... · The average particle size of zinc nanoparticles and zeta potential were measured as 53 nm. (Fig. 3) and 82 mV. (Fig

International Journal of Applied And Pure Science and

Agriculture

www.ijapsa.com

@IJAPSA-2015, All rights Reserved 19

e-ISSN: 2394-5532

p-ISSN: 2394-823X

Biogenic synthesis of zinc nanoparticles from Thevetia

peruviana and influence on soil exo-enzyme activity and growth

of peanut plants.

K. Sri Sindhura1, T.N.V.K.V.Prasad

2, P. Panneer Selvam

3 and O. M. Hussain

1*

1Department of Physics, Sri Venkateswara University, Tirupati-517 502, A.P., India,

2Nanotechnology laboratory, Institute of Frontier Technology, Regional Agricultural Research Station,

Acharya N.G Ranga Agricultural University Tirupati-517 502, A.P., India 3Department of Soil science and Agricultural chemistry, Indian Institute of Horticultural Research, Bangalore

-560089, India,

Abstract

Zinc nanoparticles were synthesized using Thevetia peruviana leaves extract and

characterized using different spectroscopic (Ultraviolet-Visible and Fourier Transform Infrared

Spectroscopy) and microscopic (Particle size analyzer, X- ray diffraction, Scanning and

Transmission electron microscopy) techniques. Absorption spectrum of zinc nanoparticles showed

broad absorption peaks at 327 nm and 254 nm. Average particle size and zeta potential were

recorded as 53 nm and 82 mV respectively. Microscopy techniques revealed triangular shaped and

poly-dispersed zinc nanoparticles. The synthesized zinc nanoparticles were applied to the pot-culture

of peanut and studied soil micro-biota and soil exo-enzyme activities and estimated the physiological

traits of peanut plants in 2 regular time intervals of 30 days and 60 days of sowing period. Zinc

nanoparticles applied to the peanut pot-culture exhibited good soil microbial and enzyme activities

by showing significant variations compared to the control and enhanced the physiological growth

parameters of peanut plants.

Keywords: Thevetia peruviana, Green synthesis, Zinc nanoparticles, Arachis hypogaea L, Enzyme

activity, Microbial activity and Physiological traits.

I. Introduction

Metal nanoparticles have various functions that are not observed in bulk phase and have been

studied extensively because of their unique and exclusive physical, chemical, catalytic, optical,

electronic, magnetic, antimicrobial, wound healing, anti-inflammatory [1] and biological properties

[2]. Though physical and chemical methods are widely used for nanoparticle synthesis, the use of

toxic compounds limits their applications. To overcome this, scientists started using biological

sources like microorganisms and plants for the synthesis of biogenic metal nanoparticles.

Application of plants and plant sources for nanoparticles synthesis is rapidly expanding stream in the

research area of nano-biotechnology. Now-a-days, the development of safe and cost-effective

methods for biogenic production of nanoparticles is of more interest due to simplicity of the

procedures and versatility [3]. Green synthesis of metal nanoparticles from plants is an interesting

aspect as the process is eco-friendly and non-toxic.

Biogenic route of nanoparticle synthesis increases the production by lowering the product

cost, compared to physical and chemical routes. Metal nanoparticles like silver [4, 5], gold [6, 7]

titanium dioxide [8], tungsten oxide [9], copper oxide [10] and zinc oxide [11] were successfully

synthesized using different plant sources by various researchers following green synthesis route. But,

International Journal of Applied and Pure Science and Agriculture (IJAPSA) Volume 01, Issue 2, [February - 2015] e-ISSN: 2394-5532, p-ISSN: 2394-823X


the synthesis of biogenic zinc nanoparticles is scant [12 - 14]. Biogenic synthesis of zinc

nanoparticles is quite interesting as zinc is an essential micronutrient for plants and also plays an

essential role in the growth and yield of plants. In general, plants absorb zinc as a divalent cation

(Zn2+

) and upsurge the soil microbial and enzyme activities [12].

Enzymes play a vital role in maintaining soil health. Most of the soil enzyme activities are

influenced by the microorganisms present in the soil. The soil enzyme activities show high potential

for biological factors of soil due to the rapid changes in soil management [15]. Soil enzymes also

play a key role in the biochemical functions of soil system [16]. Soils contain a group of enzymes,

which determines the soil metabolic protocols and these enzymatic levels vary depending on the

organic matter present in the soil, soil microbial activity and soil biological processes [17].

Thevetia Peruviana, an abundant ornamental crop, which is an evergreen tropical shrub has

yellow colored trumpet like flowers. The leaves are willow-like, linear-lanceolate and glossy green

in color. Its stem is green turning silver/gray as it ages. Leaves contain wax like coating to prevent

water loss. Flowers, leaves, seeds and roots are used in medical field as anti-microbial, anti-fungal,

anti-inflammatory, anti-diarrheal, piscicidal and anti-termite agents. The plant contains a poisonous

toxin called thevetin, which can be used as a heart stimulant [18]. These plant toxins are also used as

biological pest controls [19].

The main objective of the proposed work is to synthesize and characterize phytogenic zinc

nanoparticles using Thevetia peruviana leaves extract and study their application on Arachis

hypogaea L (peanut) pot-culture to estimate soil microbial population, soil exo-enzyme activities and

physiological growth parameters of the peanut plants.

II. Experimental

A. Material collection and synthesis of zinc nanoparticles

Fresh leaves of Thevetia peruviana were collected from the fields of Regional Agricultural

Research station (R.A.R.S), Acharya N. G Ranga Agricultural University, Tirupati, India. The leaves

were thoroughly washed using double distilled water and kept for shade drying for a week. After

shade drying, the leaves were dried in an oven for 8 hours at 65° C and made into powder. 2 gm. of

powder was added to 100 ml of distilled water in a 250 ml. Erlenmeyer flask to prepare the leaves

decoction. The decoction was boiled for 15 min and carefully filtered using Whattmann No. 1 filter

paper, in order to get a clear filtered solution, the leaves extract. 0.005 M zinc nitrate solution and

leaves extract was taken in 9:1 ratio (sample solution). The sample solution was kept for heating up

to a change in coloration from yellow to honey color and then centrifuged at 18,000 rpm for 20 min.

B. Characterization of zinc nanoparticles

The synthesized zinc nanoparticles were characterized using Ultraviolet-visible

spectrophotometer (UV-Vis, Schimadzou 4650), Fourier transform infrared spectroscopy (FTIR,

Bruker Tensor 27), Inductively Coupled Plasma-Optical Emission Spectrophotometer (ICP-OES –

Leeman Labs Prodigy XP), Particle analyzer (Nanopartica SZ - 100 Horiba), X-ray diffractometer

(XRD, Siefert model 3003), Scanning electron microscope (SEM, Carlziess EVO 50) and

Transmission electron microscope (TEM, HITACHI H-7500).



C. Pot culture experiment

Pot-culture experiment was conducted on Arachis hypogaea L (peanut) to study the soil micro-

biota (microbial population), soil exo-enzyme activity and physiological growth parameters of

peanut plants. 20 pots (sown with peanut seeds) were raised as 5 replications by adding sample

solution to 15 pots (at the time of sowing the seeds) in three different treatments (Treatments 1-3)

and 5 pots were maintained as controls.

Treatment – 1 (5 pots): 15 ml of sample solution + 5 ml distilled water.



Control (5 pots) : Without adding any sample.

Microbial population of bacteria, fungi and actinomycetes were estimated by using regular

serial dilutions and spread plate technique. For this, 3 gm. of soil was taken from each peanut pot and

fresh media for bacteria, fungi and actinomycetes were prepared. To estimate the colony count of

bacteria, fungi and actinomycetes, nutrient agar media for bacteria, potato dextrose agar media for

fungi and kennight and munnaier’s media for actinomycetes were prepared. The prepared media was

poured into the petri-plates (in laminar air-flow chamber to avoid contamination) and clearly labeled.

From the prepared serial dilutions of bacteria, fungi and actinomycetes, 10-5

dilution for bacteria, 10-

2 dilution for fungi and 10

-3 dilution for actinomycetes were poured (0.1 ml) in each petri-plate,

according to the type of microorganisms and incubated in a hot-air oven at 23 0 C. Bacteria and fungi

were incubated for 3 days, whereas actinomycetes was incubated for 5 days.

Acidic phosphatase activity, alkaline phosphatase activity and dehydrogenase activity were

performed in two regular time intervals of 30 days and 60 days of sowing period by taking 3 gm. of

soil from each peanut pot. Phosphatase activity was estimated as described by Tabatabai and

Bremner (1969) and dehydrogenase activity was estimated as described by Thalmann (1968) [20,

21].

The physiological growth parameters of peanut plants like plant height, number of leaves and

leaf surface ratio (leaf length and leaf breadth) of peanut plants were calculated in two regular time

intervals of 30 days and 60 days of sowing period. Root length, shoot length, fresh and dry weight of

roots and shoots were measured after 60 days of sowing period. At the end of pot culture, total

biomass (dry weight of roots and shoots) was measured by removing peanut plants from all the pots

and by differentiating each plant into its root and shoot. Fresh weight of roots and shoots were

immediately measured after differentiating the plants into roots and shoots. Dry weights were

measured after incubating the roots and shoots in a hot-air oven for 36 hrs. at 65ºC.

III. Results

A. Ultraviolet-Visible spectroscopy

The optical absorption spectrum of zinc nanoparticles is shown in Fig. 1. The absorption peak

for zinc nanoparticles was observed at 327 nm and a second harmonic peak at 254 nm. The zinc

content was estimated as 353 ppm [12] using Inductively Coupled Plasma-Optical Emission

Spectrophotometer.

B. FTIR studies

The functional groups of alcohols, phenols, alkenes, alkanes, carbonyls, aromatics, nitro

compounds, alkyl halides and aliphatic amines were identified at 3785.46, 3696.96, 3055.83,



2853.48, 1674.89, 1582.72, 1273.32, 1156.75 and 1013.94 cm-1

from the infrared spectrum recorded

for the leaf extract of Thevetia peruviana (Fig. 2a). Strong band of -C=O- stretch (carbonyls) was

recorded at 1674.89 cm-1

. Medium bands of –N=O- symmetric stretch (nitro compounds) and –CH2-

X stretch (alkyl halides) were recorded at 1273.32 and 1156.75 cm-1

.

Alcohols, phenols, aromatics, aldehydes, nitriles, carboxylic acids, aromatics, aromatic

amines, alkyl halides and aliphatic amines were the functional groups identified at 3617.18, 3129.36,

2728.83, 2372.72, 1672.53, 1271.20, 1160.24 and 1017.53 cm-1

from the FTIR spectrum of zinc

nanoparticles (Fig. 2b). Strong band of -C=O- stretch (carboxylic acids) was recorded at 1674.89 cm-

1. Medium bands of –C-N- stretch (aromatic amines) and –CH2-X stretch (alkyl halides) were

recorded at 1271.20 and 1160.24 cm-1

.

C. Particle size analyzer and microscopy

The average particle size of zinc nanoparticles and zeta potential were measured as 53 nm.

(Fig. 3) and 82 mV. (Fig. 4) respectively. Scanning electron microscopy [Fig. 5] and transmission

electron microscopy [Fig. 6] data revealed the presence of triangular shaped and poly-dispersed

zinc nanoparticles with a grain size of 50 ± 5 nm.

D. X-ray diffraction

The X-ray diffraction pattern of zinc nanoparticles recorded in the 2θ range 10 º - 60 º is

shown in Fig. 7. The XRD pattern exhibited (1 0 1), (2 0 1), (2 0 2), (2 0 3) and (3 0 0) diffraction

peaks at 19.66º, 36.93º, 39.05º, 43.93º and 54.84º, corresponding to the HCP structure of zinc and the

data is in agreement with JCPDF 011238 data.

E. Microbial population

Colony count of bacteria, fungi and actinomycetes was estimated in 3 different treatments

along with the controls after 60 days of sowing period (Fig. 8 and Table. 1). Among the 3 treatments,

treatment – 1 showed higher microbial population compared to treatments 2 and 3 because for

treatment-1, greater volume of sample (20 ml.) was added compared to treatment-2 (15 ml) and

treatment-3 (10 ml). Bacterial population was significantly higher (3.2 – 5.5 x 105 g

-1 dry soil) in

nanoparticles treated samples compared to the control (2.3 x 105 g

-1 dry soil). Similarly the

nanoparticle treated samples showed significantly higher fungi (1.9 -2.3 x103 g

-1 dry soil) compared

to control (1.1 x 103 g

-1 dry soil) and higher actinomycetes (0.46 – 0.84 x10

3 g

-1 dry soil) compared

to control (0.27 x 103 g

-1 dry soil). The results indicated that, the rhizosphere microbial population

was induced by the leaf extracted zinc nanoparticles. The results were represented using the ±

Standard Deviations (SD) of five replications [22].

F. Soil exo-enzyme activity

The enzyme activities were observed to be increased in response to all treatments when

compared to the control (Table. 2). The enzyme activity analysis confirmed that the zinc

nanoparticles applied treatments showed significant variations of acid phosphatse, alkaline

phosphatase and dehydrogenase enzyme activities for the treatments, compared to the controls. The

enzyme activities also increased from 30 days of sowing period to 60 days of sowing period,

compared to the work reported by Sunghyun et al. [23].

G. Physiological traits



The physiological growth parameters like number of leaves, plant height, leaf surface ratio,

root length, shoot length, fresh and dry weight of roots and shoots and the total biomass were

measured for the 3 treatments along with the controls. Among the three treatments, treatment-1

showed higher values of growth parameters against the control, compared to treatments 2 and 3.

From control to treatment-1, leaf length was increased from 1.93 cm to 2.10 cm (increased by 8.8%)

after 30 days of sowing period and from 1.99 cm to 2.50 cm (25.6%) after 60 days of sowing period.

Leaf breadth increased from 1.00 cm to 1.09 cm (30 days, 9%) and from 1.17 cm to 1.45 cm (60

days, 23.93%). Number of leaves increased from 32 to 40 (30 days, 51.9%) and from 93 to 120 (60

days, 29.03%) and plant height increased from 18.12 cm to 28.48 cm (30 days, 57.17%) and from

29.16 cm to 57.32 cm (60 days, 96.57%) (Table. 3).

From control to treatment-1, root length increased from 9.03 cm to 14.12 cm (56.36%), shoot

length increased from 36.25 cm to 50.52 cm (39.36%), fresh weight of root increased from 0.34 gm.

to 0.63 gm. (85.29%), dry weight of root increased from 0.12 gm. to 0.37 gm. (67.56%), fresh weight

of shoot increased from 8.46 gm. to 12.95 gm. (53.07%), dry weight of shoot increased from 3.07

gm. to 4.85 gm. (57.98%) and total biomass increased from 3.19 gm. to 5.22 gm. (63.63%) (Table.

4).

IV. Discussion

In general, the absorption peak for zinc oxide can be observed at a wavelength of about 360

nm [24] and the absorption peak of zinc can be observed in the wavelength range of 230-330 nm

[25, 26]. Hence, the absorption spectrum of the sample confirmed the formation of stable zinc

nanoparticles in the aqueous colloidal solution. The absorption spectrum of zinc nanoparticles

showed duel peaks due to the secondary harmonic generation.

The metal colloids in an aqueous solution and revealed that the electric dipole and

electric quadrupole contributes to the secondary harmonic generation, which may be due to the non-

linearity of the metal nanoparticles and surface plasmon resonances at the second harmonic

wavelength [27]. The occurrence of duel peaks may be due to the surface dipole and quadrupole

plasmon resonances [28]. The origin of secondary harmonic generations was due to the intrinsically

non-centro-symmetric structure of interfaces. The secondary harmonic signals were forbidden in

centro-symmetric systems and not in the non-centro-symmetric systems [29].

Secondary harmonic generations only found in metals especially in non-centro-symmetric

planar surfaces, which separates the centro-symmetric and isotropic bulk media. Bulk systems do not

show the secondary harmonic systems because of their symmetry as every molecule is oriented with

opposite molecule and the non-linear polarizations for these two oppositely oriented molecules gets

cancelled, which makes the net second-order polarization zero. Hence, the secondary harmonic

generations were not found in the bulk systems [30].

Infrared spectroscopy shows the vibrational state of the particles. When the spectrum of

Thevetia peruviana leaf extract was compared with the spectrum of zinc nanoparticles, additional

functional groups of aldehydes, nitriles and carboxylic acids were observed from the spectrum of

zinc nanoparticles due to the stretching of the bands of aldehydes (H-C=O), nitriles (C≡N) and

carboxylic acids (-C=O-). The principle involved here is the bio-reduction of metal nanoparticles by

the interaction of biological components present in the samples [31]. The infrared spectroscopy

studies thus, confirmed that the terpenoids (carbonyl groups) and flavonoids (carboxylic acids and

esters; aldehydes and ketones; aromatic compounds and amines and phenols) present in the leaves



extracts bind to the metal (Zn), and bio-reduced the metal zinc to zinc nanoparticles, by stabilizing

the metal group zinc. Hence, the bio-molecules present in the leaves extracts are responsible for

formation and stabilization of zinc nanoparticles in the aqueous medium.

Particle size analyzer studies show how strongly the sample scatters light and the scattered

light focuses on Brownian motion coming from all the directions, determining the particle size of

zinc nanoparticles (present in the aqueous colloidal solution). When light incident onto the cell, the

light scatters in all directions and the scattered light is collected at either 90° or 173° of scattering

angle. The scattering angle and the position of the cell were automatically selected by the system

depending on the concentration and the intensity of the sample. Zeta potential values greater than ±

30 mV indicate that the particles present in the solution were stable. Here, the zeta potential value of

82 mV indicated that the synthesized zinc nanoparticles were highly stable [12].

The scanning and transmission electron microscopy techniques revealed the surface

morphology [32] of synthesized zinc nanoparticles. The zinc nanoparticles were observed to be

scattered in all directions and hence, the leaves extracted zinc nanoparticles were poly-dispersed.

The acid phosphatase, alkaline phosphatase and dehydrogenase enzyme activities were

performed to test the enzymatic efficiency by applying zinc nanoparticles to the peanut pot culture.

Citrate phosphate buffer inhibits soil phosphatase activity and was based on the determination of p-

nitrophenol released after the incubation of oil with p-nitrophenol phosphate for 1 hour at 37 ºC.

Dehydrogenase activity was based on the estimation of rate of reduction of triphenyl tetrazolium

chloride to triphenyl formazan in soils after incubation at 30 ºC for 24 hours. Here, the tri phenyl

tetrazolium acts as artificial electron acceptor. The measured phosphatases and dehydrogenases were

cell bound and were not extra-cellular activities [12].

The phosphatase and dehydrogenase enzyme activities indicate the soil biological activity

and soil microbial activity. Dehydrogenases were associated with living cells and linked with the

microbial oxido-reduction processes. The dehydrogenases were highly sensitive to natural and

anthropogenic factors like soil aeration, soil aggregation, soil organic content, addition of pesticides

and insecticides and heavy metal pollution [33]. As mentioned earlier, the enzyme activity depends

on the microbial activity and thus, the increase in microbial activity was also a cause for the increase

in enzyme activities [17].

Pot-culture studies showed an increase in the enzyme activity for all the 3 treatments when

compared to the control. Slight raise in values was observed for treatment-1 compared to treatments

2 and 3 because for treatment-1, the sample (zinc nanoparticles) was added in greater volume (20

ml.) compared to treatment-2 (15 ml.) and to treatment-3 (10 ml.). The reason for performing the

enzymatic activity analysis was to report that the green synthesized zinc nanoparticles when applied

to the peanut pot-culture induces the phosphatase (acid and alkaline) and dehydrogenase enzyme

activities. Our experiment revealed that the zinc nanoparticles induced the phosphatase (acid and

alkaline) and dehydrogenase enzyme activities. Thus, the zinc nanoparticles synthesized from

Thevetia peruviana leaves extract using green synthesis route are potential, safe, non-toxic and

enhanced microbial population, soil exo-enzyme activities and growth of peanut plants.

V. Conclusion

Biogenic zinc nanoparticles have been successfully synthesized from the leaves extract of

Thevetia peruviana, following the green synthesis route. Duel peaks at 327 nm and 254 nm were

observed from the absorption spectrum of zinc nanoparticles. Particle size of 53 nm and zeta

potential of 82 mV were measured from the particle size analyzer. The zinc content was estimated as



353 ppm from Inductively Coupled Plasma-Optical Emission Spectrophotometer. Microscopy

techniques revealed triangular shaped and poly-dispersed zinc nanoparticles in the size range of 5 nm

to 50 nm. Infrared spectroscopy showed strong bands for the functional groups of carboxylic acids,

aromatic amines and alkyl halides. The pot-culture experiment conducted on peanut by applying the

zinc nanoparticles (in three different treatments) showed significantly higher values, when compared

to the controls. The soil microbial population (colony count of bacteria, fungi and actinomycetes)

and soil exo-enzyme activities (acidic phosphatase, alkaline phosphatase and dehydrogenase

activities) were observed to be increased by the application of the phytogenic zinc nanoparticles. The

leaves extracted and green synthesized zinc nanoparticles applied to the peanut pot-culture induced

the growth of peanut plants (number of leaves, plant height, leaf surface ratio, root length, shoot

length, fresh and dry weight of roots and shoots and the total biomass) . Among the three treatments,

treatment - 1 showed good results. Thus, the green synthesis route will be useful in large-scale

industries for the up production of metal nanoparticles. In near future, the application of green

synthesized zinc nanoparticles to the fields (agricultural fields) may yield better results.

VI. Acknowledgement

Mrs. Sri Sindhura Kaipa would like to thank Department of Science and Technology, New

Delhi, India, for providing INSPIRE Fellowship; Nanotechnology laboratory, Institute of Frontier

Technology, Regional Agricultural Research Station, Acharya N.G Ranga Agricultural University,

Tirupati and Department of Soil science and Agricultural chemistry, Indian Institute of Horticultural

research, Bangalore for giving permission to carry out the part of research work.

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Sri Sindhura et al.

Figure 1.Absorption spectrum of zinc nanoparticles synthesized from the leaves extract of Thevetia peruviana.

Figure 2a.FTIR spectrum of Thevetia peruviana leaves extract.



Figure 2b.FTIR spectrum of zinc nanoparticles synthesized from the leaves extract of Thevetia peruviana.

Figure 3.Particle size distribution spectrum of zinc nanoparticles synthesized from the leaves extract of

Thevetia peruviana.



Figure 4.Zeta potential spectrum of zinc nanoparticles synthesized from the leaves extract of Thevetia peruviana.

Figure 5.Scanning electron microscopic image of zinc nanoparticles synthesized from the leaves extract of Thevetia

peruviana.



.

Figure 6.Transmission electron microscopic image of zinc nanoparticles synthesized from the leaves extract of

Thevetia peruviana.

Figure 7.X-ray diffraction spectrum of zinc nanoparticles synthesized from the leaves extract of

Thevetia peruviana.

10 20 30 40 50 60

0

50

Inte

nsity (

a.u

)

2 (degree)

(1 0 1)

(2 0 1)

(2 0 2)

(2 0 3)

(3 0 0)



Figure 8.Colony count of bacteria, fungi and actinomycetes (microbial population) estimated from the soil

rhizosphere of peanut pot-culture, by applying the zinc nanoparticles (treatments - 1, 2 and 3) synthesized from the

leaves extract of Thevetia peruviana, against the control.

Table 1. Colony count of bacteria (10-5

), fungi (10-2

) and actinomycetes (10-3

).

S.No. Bacteria Fungi Actinomycetes (cfu x dilution g-1 dry soil)

T1 5.5 2.3 0.84

T2 4.7 2.1 0.53

T3 3.2 1.9 0.46

C 2.4 1.1 0.27

SE 0.08 0.03 0.01

T1-Treatment–1; T2-Treatment–2; T3-Treatment–3; C-Control; SE: Each value is the ± of five replications.

Table 2. Soil exo-enzyme activity of peanut pot-culture by the application of green synthesized and Thevetia peruviana

leaves extracted zinc nanoparticles against the controls.

S.No. Acidic Phosphatase Alkaline Phosphatase Dehydrogenase

Activity activity activity

(µg of p-nitrophenol released g-1 of soil h-1) (µg of TPF released g-1 of soil h-1)

30 days 60 days 30 days 60 days 30 days 60 days

T-1 16.77 22.71 18.87 19.15 3.82 6.71

T-2 16.74 19.15 17.38 18.26 2.05 6.33

T-3 16.71 18.07 16.70 18.03 1.49 6.24

C 15.50 14.08 15.61 14.19 1.40 5.78

SE 0.17 0.26 0.19 0.22 0.06 0.07



Table 3. Physiological growth parameters of peanut plants.

Table 4.Physiological growth parameters of peanut plants.

S.No Root length Shoot length Shoot weight Root weight Total biomass

Fresh weight Dry weight Fresh weight Dry weight

(cm) (cm) (gm) (gm) (gm) (gm) (gm)

T-1 14.12 50.52 12.95 4.85 0.63 0.37 5.22

T-2 13.20 48.64 10.12 4.82 0.51 0.26 5.08

T-3 11.19 44.80 8.61 3.19 0.38 0.16 3.35

C 9.03 36.25 8.46 3.07 0.34 0.12 3.19

SE 0.16 0.57 0.13 0.06 0.01 0.01 0.06

S.No. 30 days 60 days

Leaf length Leaf breadth Plant height No. of leaves Leaf length Leaf breadth Plant height No. of leaves

(cm/plant) (cm/plant) (cm/plant) (/plant) (cm/plant) (cm/plant) (cm/plant) (/plant)

T-1 2.10 1.09 28.48 40 2.50 1.45 57.32 120

T-2 2.07 1.06 25.50 36 2.40 1.20 49.41 101

T-3 1.98 1.02 20.27 30 2.10 1.10 32.32 96

C 1.93 1.00 18.12 32 1.99 1.17 29.16 93

SE 0.02 0.01 0.32 0.39 0.03 0.01 0.76 1.18

Documents

Biogenic synthesis of zinc nanoparticles from Thevetia ... · The average particle size of zinc nanoparticles and zeta potential were measured as 53 nm. (Fig. 3) and 82 mV. (Fig