Biomedical Engineering Reference
In-Depth Information
infected and the farmer has no other choice than to apply a strong pesticide
over the whole area of the crop. In Section 5.1.1, strategies have been described
that in the future will allow early detection of pests. When the pest is detected
at an early stage, measures can be taken locally to eliminate the pest and/
or prevent it from spreading. In some cases, the risk of large-scale damage
to the crop by certain pests is very high and the farmer will resort to pre-
ventive application of pesticides. Unfortunately, the effectiveness is reduced
under unfavorable conditions, such as heavy rain, since the chemicals can be
washed off from the plants. Not only do they lose their function for the crop,
they can also have negative effects on the soil or the aqueous environment.
Nanotechnologies can be used to produce pesticides that have controlled
release mechanisms. By encapsulating the agent in a special encapsulation
system that has a shell that can open up under well-defined conditions, the
agent will only be released if the conditions for that pest are favorable or
through the presence of certain compounds that are associated with the pest.
In specific cases, the pest (e.g., certain fungi) produces these compounds
themselves and in this way they trigger their own destruction. The shells can
also be functionalized to make the system stick to the plants more effectively,
thus reducing the amount that is washed off before it could be effective.
Although weeds are less of a threat to crops, their presence is also undesir-
able because they can limit the development of the crop because they com-
pete for certain resources such as light, water, and nutrients. Especially when
the crop is still small, its development can be seriously restricted, which
results in crop loss at harvest. Although herbicides are applied in a much
narrower and better-defined time window, these substances can also benefit
from the concepts mentioned above for pesticides.
5.1.4 Other Applications
Since nanotechnologies are enabling technologies that can be applied in
many different areas, many other applications can be envisioned in agricul-
ture (Pérez-de-Luque and Rubiales 2009). Here are some examples.
In greenhouse applications, nanotechnology is used to improve the light
transmission of a greenhouse deck, either by modifying the reflection proper-
ties of the deck material or by changing the spectrum of the light transmitted.
Self-cleaning surfaces, based on the lotus effect in which a microstructure
and a nanostructure are combined to create superhydrophobic behavior, or
on catalysis of nanoparticles of TiO
2
in combination with light to break down
organic molecules, are a simple application of nanotechnology in this case
to avoid production loss because of dirty glass. Nanotechnology can also be
used to make stronger (polymeric) materials to replace glass as a deck mate-
rial. If the deck can be made lighter, the supporting construction can be lighter,
which results in less shadow on the crop and higher yields. It also enables
choosing materials predominantly for their spectroscopic properties (which
wavelengths they transmit) and less because of their mechanical strength.
