Recent Trends and Development of Nanotechnology Application in Weed Management Dr.C.R.Chinnamuthu Professor (Agronomy) Tamil Nadu Agricultural University ISWS BC Mar 1-3, 2017 MPUAT, Udaipur
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.
Intervention with Nanotechnology
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
Intervention with Nanotechnology
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
Intervention with Nanotechnology
Viability of weed seeds are due to
• Nature of seed coat • Germination inhibitor• Food reserve• Embryonic stage
Exhausting WSBExhausting WSB
Intervention with Nanotechnology
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
Viji and Chinnamuthu 2015
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)
Viji and Chinnamuthu 2015
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
Viji and Chinnamuthu 2015
•• 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
Viji and Chinnamuthu 2015
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.
Intervention with Nanotechnology
• 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
Intervention with Nanotechnology
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
Viji and Chinnamuthu 2015
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
T3 - 200 ppm α-amylase + 1.0 g Ag nps kg tuber-1 103.59
T4 - 300 ppm α-amylase + 1.5 g Ag nps kg tuber-1 99.84
T5 - 400 ppm α-amylase + 2.0 g Ag nps kg tuber-1 100.47
T6 - 500 ppm α-amylase + 2.5 g Ag nps kg tuber-1 98.14
SEd 0.63
CD (P=0.05) 1.38
Effect of α-amylase + Silver (Ag) NPs on starch degradation of C.rotundus
Viji and Chinnamuthu 2015
Before After
Normal vs Treated tuber starch
Chinnamuthu, 2012
Intervention with Nanotechnology
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
Intervention with Nanotechnology
• 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
Improved Absorption-FoliarImproved Absorption-Foliar
Chinnamuthu, 2011
Intervention with Nanotechnology
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
Improved Absorption-FoliarImproved Absorption-Foliar
Intervention with Nanotechnology
• 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
Improved Absorption-FoliarImproved Absorption-Foliar
Intervention with Nanotechnology
Translocation• Symplast-diffusing through cytoplasm• Apoplat –diffusing through cell wall
Intervention with Nanotechnology
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
Intervention with Nanotechnology
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
Viji and Chinnamuthu, 2015
Encapsulated glyphosate with iron oxide nps Encapsulated glyphosate with silver nps
Encapsulated glyphosate with titanium dioxide nps Encapsulated glyphosate with zinc oxide nps
Viji and Chinnamuthu, 2015
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
Viji and Chinnamuthu, 2015
• 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
Viji and Chinnamuthu, 2015
• 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
Viji and Chinnamuthu, 2015
Intervention with Nanotechnology
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
Pradeeshkumar and Chinnamuthu 2014
SEM images of pendimethalin a.i.
Preparing the a.i. for encapsulation
Pradeeshkumar and Chinnamuthu 2014
MnCO3 CoreCore + Polymers
(PSS + PAH)
Hollow-ShellEncapsulation
Smart Release
Fabricated Nano-Herbicide by IDM Fabricated Nano-Herbicide by IDM
TNAU
Pradeeshkumar and Chinnamuthu 2014
CoreHerbicide Core + Herbicide
Polymers
MnCO3 Core
MnSO4 NH4HCO3 +
2. Direct method (DM)
Core + Herbicide Encapsulated herbicide
Pradeeshkumar and Chinnamuthu 2014
TEM images of direct method of nanoencapsulated herbicide
Pradeeshkumar and Chinnamuthu 2014
• 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
Pradeeshkumar and Chinnamuthu 2014
Aqueous phase
Organic phase
Encapsulated Herbicide
Pradeeshkumar and Chinnamuthu 2014
3. Solvent Evaporation Method
SEM images of nanoencapsulated herbicide by solvent evaporation method
Pradeeshkumar and Chinnamuthu 2014
TEM images of nanoencapsulated herbicide by
solvent evaporation method
Pradeeshkumar and Chinnamuthu 2014
• 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
Pradeeshkumar and Chinnamuthu 2014
10 days
20 days
30 days
40 days
Pradeeshkumar and Chinnamuthu 2014
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
Pradeeshkumar and Chinnamuthu 2014
10 days
20 days
30 days
40 days
Pradeeshkumar and Chinnamuthu 2014
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)
Pradeeshkumar and Chinnamuthu 2014
• 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.
Pradeeshkumar and Chinnamuthu 2014
Intervention with Nanotechnology
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
Intervention with Nanotechnology
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
Intervention with Nanotechnology
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