weed management nanotechnology application in recent ... chinamuthu_pl.pdf · recent trends and...

Recent Trends and Development of Nanotechnology Application in

Weed Management

Dr.C.R.ChinnamuthuProfessor (Agronomy)

Tamil Nadu Agricultural University

ISWS BC Mar 1-3, 2017 MPUAT, Udaipur

Current Status of weed Management

Issues Challenges

• Labour shortage • Labour cost• Introduction of GM

Crops• Organic agriculture

• Enlarging Weed Seed Bank

• Herbicide Residue• Herbicide Resistant

Weeds

No One Stop Shop Solution for any problem

ManualManual

MechanicalMechanical

CulturalCultural

BiologicalBiological

ChemicalChemical

??

There is an invisible firewall around the weeds which is very difficult to break

An attempt with Nanotechnology

Nano doesn’t mean the scale. It actually means…… Ø More PreciseØ Highly Accurate Ø Exact

• Exhausting Weed Seed Bankü Degrading germination inhibitorü Exhausting food reserve

• Absorption (root/shoot)• Translocation • Smart release-rainfed• Slow release-season long weed control• Rapid degradation of Herbicide residue

Issues being addressed with Nanotechnology

Issues can be addressed with Nanotechnology

• Weed Identification tool kit

• Weed based specific formulation

• In situ low cost HR estimation

Intervention with Nanotechnology

நோயநாடி நோயமுதல நாடி

அதுதணிககும

வாயநாடி வாயபபச செயல .

Disease, its cause, what may abate the ill: Disease, its cause, what may abate the ill: Let leech examine these, then use his skill. Let leech examine these, then use his skill.

Let the Scientist enquire into the nature of the problem, its cause and its method of cure and treat it faithfully according to rule.


Weed Seed BankWeed Seed Bank

• Weed seeds are like Land Mines

• It explodes when water enters

• Remain viable for several years

• It has some special kind of mechanism to fight against biotic and abiotic attack

• Priority should be given to curtail the enlargement of weed seed bank and

• Exhaust the weed seed bank


Putting Check on Enlarging WSBPutting Check on Enlarging WSB

• Inducing sterility

• Dehydrating poll grain with Nano particles (Ag/Na) spray

• Prevent the seed production

• Mostly non crop situation

Chinnamuthu, 2012

Pollen grain of parthenium


Viability of weed seeds are due to

• Nature of seed coat • Germination inhibitor• Food reserve• Embryonic stage

Exhausting WSBExhausting WSB


Exhausting WSB – with CNTExhausting WSB – with CNT• Kill the seeds instead of killing seedling• Cracks and opening in seed coat• Channelize the entry of water and chemicals• Use of Carbon Nanotube

SEM picture of nutsedge seed (a) and the surface features Carbon NanotubeChinnamuthu, 2012

CNT Fast-Forward seed germination

• CNTs penetrate seed coat• Serve as a water gate • Permeation of seed coat• Release dormancy• Speed up germination• Shortens germination

(Mariya et al., 2009)

Exhausting WSB – with CNTExhausting WSB – with CNT

purple nut-sedge

Most troublesome weed

Germination inhibitor

• Primary GI are phenolic compounds• > 23 compounds are identified in

C.rotundus• Caffeic acid, Ferulic acid, Chlorogenic

acid, Vanillic acid, Hydroxyl benzoic acid• Abiotic stress increases the quantity of GI

to prevent the germination• Degradation induce germination

Exhausting WSBExhausting WSB

Brindha and Chinnamuthu 2013

Quantification of phenolic compounds in normal and stress induced tubers of C.rotundus

Phenolic acidsConcentration (ppm)

Normal tubers Stress induced tubers

Caffeic acid 601.3 1851.9

Ferulic acid 211.7 541.2Chlorogenic acid 207.0 432.7

Vanillic acid 190.8 610.0Hydroxyl benzoic acid 87.9 152.0

Viji and Chinnamuthu 2016

Degrading the Phenolic Compounds

• Dilution effect with plenty of water

• Use of nanoparticle

Synthesize and Characterization of NPs

Iron oxide NPs Silver NPs Titanium dioxide NPs

ZnO NPs

• NPs were synthesized in the wet lab.

• NPs with more surface reactive regions initiate the chemical reaction quickly and degrade the target materials efficiently


Effect of iron oxide NPs on total phenol content of C.rotundus

S.NoIron oxide

mg/g of tuber

Phenol concentration

(mg/g of tubers)

1 T1 - Control 21.78

2 T2 - 5 mg 10.67

3 T3 - 10 mg 5.70

4 T4 - 15 mg 6.39

5 T5 - 20 mg 4.41

6 T6 - 25 mg 2.79

7 T7 - 30 mg 2.38

SEd 0.42

CD (P=0.05) 0.91

0 5 10 15 20 25 300.00

5.00

10.00

15.00

20.00

25.00

phenol concentration

Iron oxide nps conc. (mg/g of

phen

ol c

once

ntra

tion(

mg/

g tu

ber)


Effect of NPs on Vanillic acid degradation

• In vitro experiments were carried out with commercially available vanillic acid to study the degradation potential of different nanoparticles.

NPs % degradation of Vanilic acid

Fe3O4 60.6TiO2 54.5ZnO 49.3Ag 24.8


•• Iron oxide NP produce OHIron oxide NP produce OH--

•• Increased reactive OH radicals results in the Increased reactive OH radicals results in the oxidation of phenol into other intermediates. oxidation of phenol into other intermediates.

•• Induce germination of Induce germination of C.rotundus C.rotundus due to due to reduced phenol content.reduced phenol content.

How iron oxide……?

NPs Germination % of tubers (3g/kg of tuber)

VI

Fe3O4 78.7 1753TiO2 68.1 1093ZnO 74.5 1531Ag 65.6 364

Germination per cent and vigour index of C.rotundus induced by NPs


Suggestion….

Nanoparticles can be used for degrading the GI of Cyperus rotundus.

Germinated tubers could be controlled by a chemical or any one means.

Hope it is an effective way of exhausting the weed seed bank.


• H2O2 + Ag NP (50% + 505 ppm)• Act as fumigant • Kill all weeds, fungal pathogen,

bacteria and viruses• 30 ml per sq.m• Doesn’t leave any residue• Ecofriendly and biodegradable

Nano Silver

http://www.ethicsagrotech.in/

Exhausting WSB – with Exhausting WSB – with HH22OO22 + Ag NP + Ag NP


Exhausting food reserveExhausting food reserve

Tuber cross section

Starch granules

SEM Micrograph of purple nut sedge tuber cross section containing stored starch granules

Micro compartments

Chinnamuthu, 2011

NPs % degradation of Starch

Fe3O4 1.7TiO2 1.3ZnO 2.4Ag 7.5

• Ag NPs synthesized by soluble starch method have stimulant effect on starch degradation.

• Ag NPs were bio-conjugated with α-amylase and used to degrade starch present in the tubers.

Effect of NPs on Starch


TreatmentsConcentration of

starch (mg g of tuber-1)

T1 - Control 131.40

T2 - 100 ppm α-amylase + 0.5 g Ag nps kg tuber-1 112.57





SEd 0.63

CD (P=0.05) 1.38

Effect of α-amylase + Silver (Ag) NPs on starch degradation of C.rotundus


Before After

Normal vs Treated tuber starch

Chinnamuthu, 2012


Improved Absorption-FoliarImproved Absorption-Foliar

• Reduce herbicide particle size to Nano

• Dissolve the lipid polymer impregnated with waxes with the Silica Nanoparticle (SNPs)

• Active energy requiring process


• Reduce Herbicide particle size to nano

S.No. Name of Herbicide Particle Size (nm)Range Mean

1. Pendimethalin 7.83 - 49.89 16.742. Fluchloralin 15.39 - 23.50 19.95


Chinnamuthu, 2011


Addition of surfactant - decreases the interfacial surface tension of a water droplet causing the droplet to spread over the leaf surface.

Addition of nanoparticle – supply electron – charge electrically – improve herbicide diffusion through wax, cutin and pectin



• Dissolve the lipid polymer impregnated with waxes with the Silica Nanoparticle (SNPs)

• Addition of SNP with herbicide become ionic - improve the diffusion through wax, cutin and pectin corridors

Silica (silicon dioxide) nanoparticlesHerbicide droplet on the waxy cuticle



Translocation• Symplast-diffusing through cytoplasm• Apoplat –diffusing through cell wall


TranslocationEnter xylem through endodermis and pericycle from cortex in root and phloem in leaf further the movement is subjected to • Acropetal -Moving up through xylem• Basipetal – Moving down through phloem


Translocation

• Acropetal – Nanocomposite increase the concentration and move along with water and solutes by transpiration pull

• Basipetal – Addition of NPs conjugate with C6H12O6 and reach all parts of plant system

Treatments Weed control rating

Glyphosate in primary tubers

(ppm)

Glyphosate in secondary tubers

(ppm)

T1 - Glyphosate at 10 ppm 1 1.69 0.00T2 - Glyphosate at 15 ppm 1 1.73 0.00T3 - Glyphosate at 50 ppm 1 4.58 0.00T4 - Glyphosate at 100 ppm 1 7.25 0.00T5 - Glyphosate at 200 ppm 2 9.63 0.00T6 - Glyphosate at 300 ppm 2 10.46 0.14T7 - Glyphosate at 400 ppm 5 14.36 0.19T8 - Glyphosate at 500 ppm 6 17.64 0.21T9 - Glyphosate at 600 ppm 7 20.00 0.42

Glyphosate Translocation in C.rotundus tubers

Viji and Chinnamuthu, 2015

Nano spray drierNano spray drier

Capable to prepare nano-encapsulated powdered landmine

TEM image of glyphosate


Encapsulated glyphosate with iron oxide nps Encapsulated glyphosate with silver nps

Encapsulated glyphosate with titanium dioxide nps Encapsulated glyphosate with zinc oxide nps


Treatments

Translocation of glyphosate (ppm)

Primary tubers

(ppm)Secondary tubers (ppm)

T1- Control 22.3 1.01T2 - Encapsulated glyphosate 39.9 4.1T3 - Encapsulated glyphosate

with Fe2O3 nanoparticles 49.3 Not formedT4 - Encapsulated glyphosate

with Ag nanoparticles 44.8 Not formedT5- Encapsulated glyphosate

with TiO2 nanoparticles 71.1 Not formedT6 - Encapsulated glyphosate

with ZnO nanoparticles 41.3 8.1SEd 1.29 -CD(P=0.05) 2.81 -

Encapsulated complex on glyphosate translocation to the tubers of C.rotundus


• To obtain a slow and sustainable release of glyphosate and NPs, they were encapsulated with different polymers such as PVA and PSS.

• Bio conjugation of glyphosate 600 ppm with Fe2O3, Ag and TiO2 NPs at 3.0 g recorded good control of C.rotundus than zinc oxide nanoparticles.

Nano-encapsulation of Glyphosate and NPs


• Encapsulated glyphosate with TiO2 NPs recorded higher herbicide translocation to the primary tubers.

• Encapsulated glyphosate conjugated with Fe2O3, Ag and TiO2 NPs didn’t produce any secondary tubers of C.rotundus.

• The encapsulated herbicide with different NPs is safe and did not influence the activity of earthworms significantly during the observation period of 40 days.

Nano-encapsulation of Glyphosate and NPs



1.1. Time bound smart release – Time bound smart release – Rainfed Ecosystem Rainfed Ecosystem

2. Slow release -Season Long Weed Control

Achieved by• Encapsulating the a.i with protecting

material for slow release• Antimicrobial component to reduce the

microbial degradation.• Capping agents to sustain under

unfavourable weather condition

TNAU

Slow Slow Release Nano herbicide for Release Nano herbicide for season long weed controlseason long weed control

Indirect method of nanoencapsulation (IDM)

Direct method of nanoencapsulation (IDM)

Direct nanoencapsulation by solvent evaporation method (SEM)

Direct nanoencapsulation by Nano Spray method (NSM)

How to encapsulate any a.i…

Selection of Water soluble polymers

Polymers Solubility (12 hrs)

Chitosan Not soluble

Poly propylene Not soluble

Polyethylene Partially soluble (50%)

Poly styrene Partially soluble (50%)

*Poly vinyl alcohol Soluble (with 5 min)

*Poly (allylamine hydrochloride) Soluble (with 5 min)

*Poly (sodium 4- styrenesulfonate) Soluble (with 5 min)

*Poly vinyl pyrolidone Soluble (with 5 min)

*Starch Soluble (with 5 min)

*Preferred for encapsulation studies Pradeeshkumar and Chinnamuthu 2014

• Synthesize uniform spherical size MnCO3 core

• Coat the MnCO3 core with bilayers of polymers viz., PSS (-), PAH (+) by Layer by Layer (LbL) assembly method

• Treat the core shell with HCL to etch out core and to form hollow shell

• Load the hollow with pendimethalin active ingredients passively (by the utilizing permeability of the polymer layer in the presence of solvent used for dissolving the herbicide)

1. Indirect method (IDM)

Pradeeshkumar and Chinnamuthu 2014

Nano core preparation

CaCO3 MnCO3

Clumping of nanocore

Spherical shaped porous MnCO3 nano core


SEM images of pendimethalin a.i.

Preparing the a.i. for encapsulation


MnCO3 CoreCore + Polymers

(PSS + PAH)

Hollow-ShellEncapsulation

Smart Release

Fabricated Nano-Herbicide by IDM Fabricated Nano-Herbicide by IDM

TNAU


CoreHerbicide Core + Herbicide

Polymers

MnCO3 Core

MnSO4 NH4HCO3 +

2. Direct method (DM)

Core + Herbicide Encapsulated herbicide


TEM images of direct method of nanoencapsulated herbicide


• Preparation of organic phase with pendimethalin and PEG

• Preparation of aqueous phase with Starch with different concentration

• Here solvent ratio and the reaction temperature aided in loading the herbicides and its efficiency differ correspondingly

3. Solvent Evaporation Method


Aqueous phase

Organic phase

Encapsulated Herbicide


3. Solvent Evaporation Method

SEM images of nanoencapsulated herbicide by solvent evaporation method


TEM images of nanoencapsulated herbicide by

solvent evaporation method


• Single Coating - Polyallylamine Hydrochloride (PAH)

• Double Coating - PAH + Poly Styrenesulfonate (PSS)

• Triple Coating I – PAH + PSS + Polyvinylpyrrolidone (PVP)

• Triple Coating II – PVP + PSS + PAH

How to Achieve Slow or Quick release?

Layer combinations

4. Spray Dry method

Aqueous phase

Encapsulated Herbicide

Organic phase

Layers Quantification (ppm)

3rd Day 10th Day 20th Day 30th Day40th

DaySingle layer 1.12 1.03 0.37 0.48 0.43Double layer 1.19 1.28 1.30 1.34 1.59Three layer I 0.57 0.67 1.05 0.39 0.37Three layer II 0.61 1.09 1.19 0.37 0.43

Direct Encapsulation - GC


10 days

20 days

30 days

40 days


Starch con.Quantification (ppm)

3rd Day 10th Day 20th Day 30th

Day40th

Day4% Starch 1.10 1.11 1.41 0.22 0.336% Starch 1.52 1.30 2.50 3.06 3.648% Starch 1.28 1.11 1.39 0.20 0.23

Solvent Evaporation - GC


10 days

20 days

30 days

40 days


Direct Encapsulation- Pot culture Experiment

Treatment detailsT1 - Single layer coating - Poly Allylamine Hydrochloride (PAH)T2 - Double layers coating - PAH + Poly Styrene Sulfonate (PSS)T3 - Triple layers coating I - PAH + PSS + Poly Vinyl Pyrrolidone (PVP)T4 - Triple layers coating II - PVP + PSS + PAHT5 - Commercial formulation T6 - Control

Each pot is filled with one kg of red soil and the weeds such as Cynodon dactylon, Cyperus rotundus and Parthenium hysterophorus are sown along with blackgram seeds.

Blackgarm (CO 6)


• In single layer weeds were germinated 10 DAS.

• In double layers, o triple layers coating method I & o triple layers coating method II

• No weeds were germinated even after the 25 DAS.



Rapid degradation of Herbicide Residue

Intervention with Nanotechnology In situ low cost HR estimation

• Pendimethalin - widely used dinitroaniline herbicide • Adsorbed strongly to soil organic matter and clay• Soil half-life is 90 days• A persistent bio-accumulative toxin by the US EPA • Classified as possible human carcinogen (Group C)• Once absorbed into plant tissues, translocation is

limited and pendimethalin breaks down via oxidation


Quick Detection of PND

• ctDNA (new generation biomarkers) • EtBr (fluorescent tag) / Acridine orange (nucleic

acid-selective fluorescent cationic dye) • Zero valent NP (catalyzer) • Immobilize the ctDNA with EtBr / Acridine

orange on a nanoparticle embedded dip stick.• Drop of analyte on the dip stick bind with DNA

and fluoresce on excitation with IR/UV


Quick Detection of PND

Presence of HRPresence of HR

Nanoparticles for Herbicide Residue detoxification

• Nanoscale iron particles have large surface areas and high surface reactivity

• They provide enormous flexibility in insitu applications

TEM image and Atomic resolution of the Fe3O4 nanoparticles

Susha and Chinnamuthu 2009

Herbicide Persistence

• Atrazine is a chlorotriazine herbicide• Prone to leaching and runoff • Limit the choice of crop in the next season• Removing Cl from Atrazine looses its herbicidal

property• ZVI NPs remove Cl from Atrazine

TNAU

C8H14ClN5

1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine

Fe3O4

Degradation of atrazine (1 ppm) using Ag modified Fe3O4 - CMC NPs

Time(h)Normalised

concentration C/C0

0.5 g/l 2 g/l

0 1.000 (0) 1.000 (0)

1 0.440 (56) 0.365 (63)

2 0.360 (64) 0.365 (63)

3 0.350 (65) 0.335 (66)

4 0.340 (66) 0.295 (70)

5 0.320 (68) 0.235 (76)

6 0.250 (75) 0.190 (81)

12 0.180 (82) 0.115 (88)

The amount degradation of atrazine was measured by HPLC and GC/MS. After twelve hour of application of 0.5 g/l of different iron based nanoparticles, Silver (Ag) modified Fe 3 O 4 -CMC recorded 82% degradation and ZVI - Pd - CMC recorded 73% degradation. At a higher concentration of 2 g/l of the nanoparticles, Silver (Ag) modified Fe 3 O 4 - CMC observed 88 % degradation and ZVI - Pd – CMC observed 77% degradation.

Susha and Chinnamuthu 2009

Acknowledgement

• Madras University, Chennai• Special Grant 50 crore, ICAR, New Delhi,• Nano mission, DST, New Delhi• Major Research Project, UGC, New Delhi• CRP-Nano Platform, ICAR, New Delhi• NST, TNAU, Coimbatore

I Sincerely Acknowledge

Dr. Joseph Irudayaraj, Professor, Purdue University, USADr. Mehboob B. Sheikh, Ph.D, Professor, FAMU, Florida, USADr. P. Pandian, Professor, Nano Science, University of MadrasDr. C. Ramasamy, Former Vice-Chancellor, TNAU, Coimbatore-3Dr. B. Chandrasekaran, Former Director of Research, TNAU, Coimbatore-3Dr. S. Sakaran (Late), Former Vice-Chancellor, TNAU, Coimbatore-3Dr. D. Ravisankar, TNAU, Coimbatore-3Ms.V. S. Susha, TNAU, Coimbatore-3Ms.V. Kanimozhi , TNAU, Coimbatore-3Mr.N. Sunilkumar, TNAU, Coimbatore-3Ms.K. Brindha, TNAU, Coimbatore-3Dr. T. Pradeesh Kumar, TNAU, Coimbatore-3Dr. N. Viji, TNAU, Coimbatore-3Dr. C.Chinnusamy, Professor, Weed Science, TNAU, Coimbatore-3

Thanks for your patient hearing Thanks for your patient hearing

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