Nanomaterials have potential applications in plant protection and agriculture. They can be engineered to have properties like permeability and biodegradability that increase their affinity to targets like pests and pathogens. Nanopesticides and nanofertilizers allow slow release and targeted delivery of agricultural chemicals, reducing usage amounts. However, some negative effects like toxicity, chemical injuries to plants, and health risks must still be addressed through further research. Overall, nanotechnology shows promise for more effective and sustainable crop protection and production if its risks can be properly managed.

1. Application of Nano
Materials in Plant Protection
H.M.R.Hennayaka
AG/2011/3175
Faculty of Agriculture
University of ruhuna

2. What are nanomaterials?
• Materials, whether of natural or manufactured origin,
possess one or more external dimensions in the range of
1−100nm .
• Nanomaterials
fertilizer,
Plant protection things - pesticides, fungicides,
weedicides
Plant pathogen detection tools

3. Weeds
Plant protection
Pathogen
Pest

4. • Small engineered structures with useful pesticidal
properties such as,
Stiffness
crystalinity
permeability,
biodegradability
large specific area
it increased affinity to the
target.(Bouwmeester et al., 2009; Bordes
et al.,2009)
• Nanopesticide delivery techniques are nanoemulsions,
nanoencapsulates, nanocontainers, and nanocages

5. • Nanomaterials can be used as a coating or protective layer
to enable slow release of traditional pesticides and
fertilizers ( Corradini et al., 2010)
• Pesticides inside nanoparticles are being developed that
can be timed-release or have release linked to an
environmental trigger (Nair et al., 2010).
• Examples
1. Formulation of artificial polymer-free nanopermethrin
as an effective larvicide that was stabilized by plant
extracted natural surfactants (www.ijcmas.com)

6. Ex 2
The essential oil from garlic loaded on polymer NPs (240
nm) coated with polyethylene glycol (PEG) to evaluate their
insecticidal activity against adult Tribolium castaneum.
Possibility of PEG coated NPs loaded with garlic essential oil
for control of storage pests. (Ghormade et al., 2011).

7. Antifungal activity
• Nano Ag is known to have strong bactericidal and broad
spectrum antimicrobial activities.
• It reduces various plant diseases caused by spore producing
fungal pathogens.
Ex 1. NP Ag has the antifungal activity on
Bipolaris Sorokiniana and Magnaporthe
grisea to reduce fungal diseases on
perennial ryegrass (Jo et al 2009).

8. • The efficacy of Ag NPs in extending the vase life of gerbera
flowers was also studied and the results showed
- inhibited microbial growth and
- reduced vascular blockage
which increased the water uptake and maintained the
turgidity of gerbera flowers. (Nair et al., 2010).
Ex 2
• ZnO nanoparticles inhibited the fungal growth
of Penicillium expansum by influencing cellular
functions, which caused deformation in mycelia
mats. (Abd-elsalam 2013).

9. • TiO2 has excellent efficacy in Oliver cereal like maize by
reducing
the effect of Curvularia leaf spot
and bacterial leaf blight disease incidence and severity.
(Mahmoodzadeh et al., 2000)

10. Ex 4
• Antifungal activity of NP Cu2O on Phytothphora infestans
with tomato.
• The foliar application resulted in significantly greater
protection (73.5 %) from the pathogen, compared to the
bulk amendment (57.8 %).(Servin et al., 2015)

11. Ex 5
• Some of the nano particles are used for controlling plant
diseases such as nano forms of C, Ag, Si and aluminous
silicates.
• A combination of TiO2,Al and Si was reported to be
effective in controlling downy and powdery mildew of
grapes. (Bowen et al., 1992)
• The use of nano formulations may offer new ways to
enhance the stability of these biological agents (Ghormade
et al., 2011).

13. Nanoherbicide
• Herbicides inside nano particles are developed
that can be timed-release or have release
linked to an environmental trigger .
• Less herbicide is required to achieve the
reduction weed reduction effects .
• If the active ingredient is combined with a
smart delivery system, herbicide will be applied
only when necessary according to the
conditions present in the field. (Gruère et al.
2011a)

14. Nano fertilizer
• Use of nanoscale nutrients to suppress crop disease.
• Amendment protocols necessary to maximize plant health
often vary with the level of infection or absence of the
pathogen.
• Micronutrients are critical in the
defense against crop disease, with
tissue infection inducing a cascade
of reactions commonly resulting in
the production of inhibitory
secondary metabolites.

15. • These metabolites are often generated by enzymes that
require activation by micronutrient cofactors.
• The use of nanoparticle-based micronutrient formulations
may offer(Singh, 2012)
a highly effective novel platform for crop
disease suppression
yield enhancement through more
targeted
strategic nutrition-based promotion of
host resistance.

16. • Nano particles may enter plant leaves through stomata and
the cuticle structures.
• NP metals/metal oxides are more effectively translocated
than corresponding bulk elements and that this greater
transportability exists in both xylem and phloem.
• Sufficient micronutrient content
in key tissues will enhance plant
defense in the presence of
pathogens but a number of factors
may limit this supply.

17. • Nonessential inorganic compounds may play in the
activation of host defense mechanisms.
Ex
1. Mn, Cu, and Zn enhance disease resistance by activating
the host defense enzymes phenylalanine ammonia lyase
and polyphenol oxidases. (Evans et al., 2007)
2.Enhanced disease defense may involve non-essential
elements such as Al and Si. (Shew et al., 2007)
3.Orthophosphate and CaCl2 amendment increased the levels
of phenolic compounds that subsequently reduced damage
from Fusarium wilt. (Biswas et al., 2012).

18. Nanosensors
• Nano sensors with immobilized bio receptor probes that
are selective for target analyzing molecules .
• Nano-sensors use to determine the time of crop harvest,
detect crop health and determine microbial or chemical
contamination of the crop.

19. • Nano sensors used to diagnose disease caused by infecting
soil microorganisms, such as
viruses,
bacteria,
and fungi
via the quantitative measurement of differential oxygen
consumption in the respiration (relative activity) of good
microbes and bad microbes in the soil. (Rai et al., 2012).

20. Positive effects of Nano
materials in crop
protection

21. • Nano – encapsulated agrochemicals designed in such a
way that they possess all indispensable properties such as
effective concentration with high solubility,
stability and effectiveness,
time controlled release in response to certain
stimuli
enhanced targeted activity
less Eco toxicity with harmless
effortless mode of delivery thus avoiding
repetitive application.

22. Negative effects of nano materials
• Nano particles on biological systems and the environment
such as toxicity generated by free radicals leading to lipid
peroxidation and DNA damage.
• High concentration of nanosilica silver produced some
chemical injuries on the tested plants (cucumber leaves
and pansy flowers).

23. • Extremely high doses of these materials are associated with
fibrotic lung responses and result in inflammation and an
increased risk of carcinogenesis. (Oberdorster et al., 2005)

24. References
• ALEXANDER GOGOS, K. K., AND THOMAS D. BUCHELI 2015. Nanomaterials
in Plant Protection and Fertilization. journal of agricultural and food
chemistry.
• DIMKPA, A. S. W. E. A. M. R. D. L. T.-R. H. H. J. C. W. P. B. C. 2015. A review of
the use of engineered nanomaterials to suppress plant disease and
enhance crop yield. Springer Science+Business Media
• JO, Y.-K., KIM, B. H., AND JUNG, G. 2009. Antifungal activity of silver ions
and nanoparticles on phytopathogenic fungi. Plant Disease, 93, 1037-1043.
• R. KHOT A, S. S. A., JOE MARI MAJA A, REZA EHSANI A, EDMUND W.
SCHUSTER 2012. Applications of nanomaterials in agricultural production
and crop protection. Crop Protection 35 64-70.
• RATHORE, S. A. A. P. 2014. Nanotechnology Pros and Cons to Agriculture: A
Review International Journal if Current Microbiol Application 3(3), 43-55