Plant Diseases—Control and Remedy Through Nanotechnology - Crop Improvement Under Adverse Conditions - page 226

Ligands

Nucleic acid

Drug

Core

Protein coat

Shell

a b c

Fig. 10.1 Schematic representation of different nanodevices that could be successfully used for
the control of various plant diseases. (Adopted from Perez-de-Luque and Diego 2009 )

treatment of diseases, rapid disease detection, enhancing the ability of plants to ab-
sorb nutrients, etc., (Carmen et al. 2003 ; Perez-de-Luque and Diego 2009 ).

2 Nanoformulations for the Control of Plant Diseases

Nanotechnology provides new ways for improving and modifying existing crop
management techniques. Plant nutrients and plant protecting chemicals are con-
ventionally applied to crops either by spraying or broadcasting. Due to problems
such as leaching of chemicals, degradation by photolysis, hydrolysis and microbial
degradation, only a very low concentration of chemicals, which is much below the
required minimal effective concentration, reach the target site of crops. Hence, re-
peated application is necessary to have an effective control, which might cause some
unfavorable effects such as soil and water pollution. Nanoformulated agrochemi-
cals should be designed with necessary properties such as effective concentration,
time-controlled release in response to certain stimuli, enhanced targeted activity
and less ecotoxicity with safe and easy mode of delivery, thus avoiding repeated
application (Green and Beetsman 2007 ; Tsuji 2001 ; Nair et al. 2010 ) (Fig. 10.1 ).
As in the case of delivery of nanodrugs in humans, controlled release (CR) of
agrochemicals has gained increased attention now a days. Controlled release is an
important technique utilized in various fields for supplying a prescribed amount of
necessary material at desired time. The encapsulated particles are the most com-
monly used functional particles for controlled release because the active compo-
nent occupies large volume fraction, and the release rate of core material is of zero
order, which is governed by the diffusion of dissolved material in the coating layer
(Ito et al. 2003 ; Li et al. 2006 ). The interactions between the matrix and the ac-
tive substances are important and this in turn may control the CR properties of the
formulation such as diffusion, reaction rates or other physicochemical parameters.
In addition, manipulation of the appropriate barriers, the target and the fate of the