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Chemical Intervention

spraying in a farm

Chemical intervention in orchards plays a crucial role in modern agriculture by aiding in the control of pests, diseases, and weeds, ensuring the health and productivity of fruit-bearing trees. However, reducing chemical intervention is  important to mitigate potential adverse effects on the environment and human health. Embracing sustainable practices, such as integrated pest management and minimal intervention, can create a balance between the necessity of chemical intervention and the imperative to minimize its environmental impact

Long-term effects of high chemical intervention

Long term effects of chemical intervention

Excessive use of pesticides can lead to the development of resistant pests and harm non-target organisms, disrupting ecosystem balances. Moreover, chemical residues may find their way into water sources, posing risks to aquatic life and human consumption.

tree fruit

Overuse of pesticides can lead to the development of resistant strains of pests and diseases, rendering the chemicals less effective over time. This creates a cycle where farmers have to use heavier or more frequent applications, or even stronger chemicals, to combat the evolving threats. Not only does this get very expensive in both cost and labour, it also exacerbates the potential for ecological imbalances.

Continued high level application of pesticides and fertilizers can result in the contamination of soil and water resources. Runoff can reach and contminate nearby water bodies or groundwater sources, Residues in the soil can accumulate over time, affecting soil quality and microbial diversity. Relying on chemical fertilizers has been shown to lead to soil degredation and reduced healthy microbial activity (For more on soils management, see the Soils page)

Beyond these immediate ecological and health concerns, the broader impact on biodiversity is a critical issue as well. Indiscriminate use of chemicals can harm non-target species, including beneficial insects, pollinators, and natural predators that contribute to a balanced and sustainable ecosystem.  Read more on encouraging native pollinators and beneficials on the farm

Best Management Practices

Best Management Practices


  • Check all pesticide options available and choose the least harmful. What is the toxicity of the product to bees and other beneficials? How long do residues last in soils? This information can be found on the label, the Pest Management Regulatory Agency (PMRA) website, or get advice from your local pesticide supplier.

  • Apply at the lowest label effective rate reduces the amount of pesticide in the environment and also saves money.

  • Do everything you can to stop spray drift. Air-blast sprayers can produce finer droplets with greater drift potential. Consider redirecting or turning off nozzles, and test and calibrate spray nozzles each year. Be fanatical about checking wind and temperature conditions before spraying.

  • Plan spraying to avoid the time when pollinators (honeybees AND native insects) are most active. Remember that native pollinators and beneficials are active at much lower temperatures (12°C) than honeybees.

  • Avoid spraying during flower bloom times (both crops and wildflowers) as this is when lots of native pollinators will be hanging around. If spraying is unavoidable, mow areas within the spray zone to reduce the amount of beneficials in the area

  • Get help from the "locals" - start implementing integrated pest management principles and have wildlife do some pest control work for you


  • Similar precautions must be taken with herbicides as pesticides regarding spray drift, lowest effective label rate, and least harmful choice of herbicide.

  • Keep large spray-free buffer areas around any and all areas of water. This includes seasonally flooded areas, as residues can be picked up when the water rises.

  • Though they must be reapplied every few years, spreading bark mulches under trees are an excellent way to reduce reliance on herbicide. Paired with a mix of ground cover crops such as grasses, clovers, and mow-able wildflowers such as yarrow and pussytoes in alleyways, this method requires minimal spot spraying and just occasional mowing. Concerns about mulches tying up soil nitrogen are debatable, and would likely only occur just at the top of soil and not below with the roots.


  • Regularly test soils and apply only that which is needed, ensuring a healthy balance within soil. Slow release fertilizers will create less runoff contamination.

  • Consider using composts, mulch, bone meal, and other natural fertilizers. These have the benefit of enriching and adding to soil structure and content as a whole instead of just providing the each nutrient for the tree.

Low-intervention and Spray-free

Low-intervention and natural farming

The focus of low-intervention farming (also called minimal intervention farming, natural farming, etc), is to dramatically reduce the inputs to an orchard and build an orchard ecosystem that functions on its own in many ways. Low-intervention farmers have many techniques to help them avoid using chemicals unless necessary.

  • Monitoring: thoroughly inspecting and tracking the presence of pests as well as weather conditions allows for pesticide application only when needed instead of on a potentially unneccesary schedule.

  • Good cultural practices can reduce the need for chemical intervention by making the overall orchard environment less friendly to pests. For instance, keeping fruit trees pruned allows good airflow and can reduce fungal growth.

  • Mechanical controls such as traps and vacuums can be used to reduce the volume of pests

Rodenticides (rat poisons) aren't necessarily a direct component of orchard management, but they can affect the orchard ecosystem nonetheless through secondary poisoning.
Secondary poisoning occurs when a predator or scavenger eats a poisoned animal and becomes poisoned itself and it frequently occurs with predators like eagles, badgers, owls or bobcats consume a rodent that has eaten rat poison but has not yet died. This does not always result in the animal's immediate death, but can cause cruel 'sub-lethal' effects such as reduced organ function, reduced ability to hunt due to symptoms, or difficulty regulating body temperature. This can also be a risk to farm dogs if they posses a high prey drive.

There are many things you can do manage rodent populations on the farm, including managing attractants, encouraging wild predators, trapping. Learn more about managing rodents on the Wildlife Management page.

Rat poisons

Rat Poisons

Image by ifer endahl

Further Reading

The following resources are information-only. Find the Financial Assistance page here

Pesticide Stewardship: website dedicated to responsible pesticide use

Health Risks associated with glyphosphate use

Canadian Science Publishing: Strategies and tactics for herbicide use reduction in field crops in Canada

Environmental Protection Agency of Southern Australia Responsible Pesticide Use Guide

University of Vermont: Responsible herbicide on Vermont farms use contributes to huge improvements in soil and water quality

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