Our strategy for Integrated Pest Management (IPM) relies on a holistic approach; one that considers the many facets of cultivation- from the interaction of molecules and genes to the intersecting life cycles of pests and crops. This undertaking is ideally accomplished considering the whole context of a specific locale. There are five general classifications I use to identify preventative and curative treatment techniques in an IPM program: physical, chemical, biological, genetic, and cultural. These classifications are based on their mechanism of effect and application process. Perhaps some of the oldest and most widespread treatments used in agriculture are those that pose a physical obstacle to the pest. They are popular in their cost effectiveness and the minimal effort needed to maintain once set up. Barriers like mesh insect screens and wind walls prevent pest ingress and take a proactive approach to thwarting a problem before it has a chance to take hold. Manipulation of the type of sunlight/ range of UV light allowed into the grow space also takes advantage of pests’ natural attraction or aversion to certain wavelengths of light.
In an agricultural context, chemical treatments refer to the classification of compounds known generally as pesticides and can be produced through biological sources or synthesized in a lab. The compound Beauvericin for instance, is an insecticide produced by the fungal entomopathogen Beauveria bassiana. This fungus is naturally found in soil and is used to infect and dry out various pests with no adverse effects on humans. Simple compounds like potassium bicarbonate are implemented to neutralize the effect of fungal pathogens like powdery mildews. Compounds are also used to improve plant health by introducing plant hormones that stimulate the Induced Systemic Response of the immune system.
It is important to know the physical properties of the compounds in use in order to be compliant with safety regulations. Translaminar compounds move into internal plant tissue and stay only where they make contact, while systemic compounds move into internal tissues and circulate throughout the plant body. It is also important to make sure to comply with your local regulatory agencies regarding the licensure for pesticide application. Biological agents enlist the help of other species found in and around the agricultural space to provide solutions to a problem. These treatments can be a direct application of biocontrol agents like predatory mites or pathogenic microbes that feed on and reduce the pest population. They can also be residents of the soil microbiome or found on the plant itself as symbiotic fungi that use the pests as hosts. Treatment can also include the indirect effects of banker plants or companion plants that house and attract populations of desirable biocontrol agents or produce a pest deterring chemical in their roots or foliage.
Genetic considerations are a facet of IPM that is often underappreciated or considered outside the scope of the farmer when in actuality, farmers have been manipulating genes since the start of the agricultural revolution. Breeding hardier, more tolerant, greater yielding plants has long been a goal of farmers and now that we can sequence the genome of a crop, pest, or soil microbiome, we can better understand how certain genes affect tolerance and immunity. For instance, some of the genetic code associated with the biosynthesis of THC in Cannabis is linked to an increased resistance to powdery mildews like Golovinomyces cichoracearum, a species documented to damage foliage. Microbiome compatibility is another critical aspect to consider now that we have a greater understanding of genetics. The relationships between the plants and mycorrhizae or bacterial mutualists are based on a complex interaction of dynamic factors coded by genes that when in balance, leads to a more robust ecosystem between plant and soil. Furthermore, though cultivators cannot directly alter the genetic composition of their plants, various environmental interactions can facilitate or depress the expression of genes though Systemic Acquired Resistance and Induced Systemic Response, both fundamental aspects of plant immune response. Having an appreciation for these physiological considerations can be useful when formulating a cultivation plan. Cultural treatments are the actions of the cultivators whose methods have a ripple effect on their crop. They are often some of the most influential and cost-effective treatments to employ because they rely on changing simple behaviors. These best practices include following proper sanitation protocols so as not to expose the plants to pathogens and taking the time to devise and execute a crop scouting plan. It is important to implement the idea of “Best Practices” in order to ensure your actions aren’t needlessly harming your plants and creating more work for yourself. Poor processes can be highly damaging to productivity and sometimes even be the cause of cultivation problems.
A coordinated effort is an effective effort and an Integrated Pest Management program aims to provide the farmer with a comprehensive plan in order to yield the best crop possible. When all of the components are evaluated and come together properly the crop will flourish.
Author: Matthew Gates