While following manufacturer’s instructions and adhering to GAPs is enough to reduce some inefficiencies in pesticide use, it’ll only get you so far. And while it may be improbable to eliminate the impact of pesticides entirely, with technology we can certainly mitigate it further!

We’ll start by talking more conventional improvements to systems before moving to more exciting and innovative systems.

In part 5 we talked about how spray pressure affects the size of droplets and how it may affect drift. Indeed, to a layman droplet size being an avenue for optimization may be quite surprising, but size really does matter in this context. Droplets that are very small are particularly susceptible to drift, whereas those that are very large are prone to bounce or run off the crop surface. Hence improved nozzle designs which produce more consistent and optimally sized droplets can increase efficiency of pesticide use, reducing both the volume of pesticide required and the risk of pollution.

These nozzles may be an improvement in mechanical design to produce consistent
droplet sizes such as in the Controlled droplet application system (CDA). Unlike traditional nozzles which force liquid into the nozzles which then break the liquid into droplets with a large range of sizes and form the spray pattern, CDA employs a spinning disc which liquid is dropped onto, this liquid is forced to the edge of the disc by centrifugal force where it is then atomised by a serrated surface. Producing a very consistent droplet size. The size of the droplets can be adjusted precisely to reduce drift through changing the flow rate of liquid and the speed of the spinning disc.

Additionally, low efficiency, (less than 25%, according to Moon et al. (2003)) of pesticide deposition is also due to aqueous pesticide solution not adhering to target plants. Using Electrostatic Nozzles, which apply electrostatic charge to atomized droplets, the droplets will be attracted to the crop surface, which was suggested by Moon et al. (2003) to be capable of doubling deposition efficiency!

Moving onto even more exciting developments, there are even drones that are programmed to fly over crops, employing sensors and GPS to carry out more targeted sprays that limit a pesticide’s wider environmental impact (Figure 1).

Natural solutions are also being considered as well, plant and fungal chemicals that can repel or attract insects, or using other insects to protect crops, such as parasitoid wasps that prey on pest species while also having the capability to act as pollinators in some cases.

While synthetic pesticides may be a necessary evil, for the foreseeable future, with improved technologies and environmental awareness, used in conjunction ecological and biological knowledge we are inching closer to designing a holistic solution for pest management.