Pesticides such as weedkillers (herbicides) and insecticides can be selective (or non-selective) and systemic (or contact). Selective plant protection chemicals only affect certain species, commonly certain weeds. Non-selective chemicals are useful in a large breakout, but risk contaminating wider areas, and weeds as well as other plants.
Systemic chemicals spread through the whole system of an organism, so if the leaves are sprayed, the chemical will reach the roots and other parts. Contact chemicals require application directly onto the target area in order to be effective.
Resulting issues with the use of these protective plant chemicals include leaching into the wider environment and potentially spreading through food chains, toxicity to certain animal species, and providing a strong selection force that results in resistance against the further use of pesticides, similar to the development of antibiotic resistance in pathogenic bacteria.
In order to mitigate these issues and provide the most efficient protection to crops, biological control strategies as well as integrated pest management strategies are employed.
Biological control involves the use of a natural predator of the pest being used to keep its spread in check, while the integrated management (IPM) involves the combination of both chemical control and…