Page 125 - CW E-Magazine (22-10-2024)

Point of View

Biologicals & chemical crop protection will together

aid sustainable agriculture

Biological crop protection, often referred to as biocontrol, is a natural and sustainable approach to managing pests and diseases in
agriculture. Instead of relying on synthetic chemicals, which are currently the mainstay of crop protection, beneficial organisms such as
predatory insects, parasitic wasps, predatory mites, nematodes, and microorganisms are used. Unlike conventional chemical pesticides,
which can have negative impacts on the environment and non-target organisms, biological crop protection is both eco-friendly and sustainable,
ensuring the health of crops without compromising the environment.

Choosing biological crop protection aligns with the broader goals of sustainable agriculture, promoting environmental health, food safety,
and long-term crop resilience while minimizing adverse effects on ecosystems and human well-being.

Interest in biological systems, in particular, and new strategies in conventional chemical control, as well, stem from several other factors,
notably the development of resistance to many pesticides, as well as the limited options available in modes of action of synthetic options.

What are biologicals?
Biologicals are products that contain beneficial, naturally occurring microorganisms or microbial derivatives as active ingredients.
Importantly, these active ingredients are not significantly altered from their natural state, either functionally or structurally.

Biologicals can be broadly classified into three main categories:
 Biostimulants (or enhancers), which are substances that enhance plant growth, health, and productivity The list includes adjuvants,
amino acids, microbial inoculants, and plant growth regulators.
 Biopesticides, which are products that protect against or are used to directly control fungal pathogens (biofungicides), insect pests
(bioinsecticides), or weeds (bioherbicides).
 Biofertilizers, which enhance nutrient availability and improve uptake of nutrients for plant growth.

Biologicals work in many ways. They can fight pests directly, colonize roots of plants to act as a barrier against pests or stimulate the
plant to vigorously grow and defend itself. They have unique modes of action and help prevent resistance development. In addition to offering
effective pest control, some biologicals act symbiotically with the crop to increase growth, improve nutrient uptake and prime the plant’s natural
defences. There is even overlap of biological activity in some; a biopesticide can control pests and disease while acting as a biostimulant.
Benefits and challenges
Farmers can apply biologicals – with the same equipment used for their chemical products – directly to plants or to the soil in which
the plants are grown, or as a seed treatment. Because they may contain living organisms, biologicals may have certain storage, handling
and application requirements critical to their efficacy. Usage practices typically detail proper storage temperature, application timing and
methods, product shelf-life and compatibility.

One of the important advantages of biologicals is that they are often exempted from Maximum Residue Limits (MRLs) of pesticides –
helping to improve the global marketability of crops treated with them. MRLs have become a bone of contention in international trade
today, and the limits imposed on them, according to industry associations here, are at times unscientific, and ‘weaponised’ for protecting
a country’s agricultural sector.

One of the characteristics of most biologicals is that they typically deliver lower levels of control and more variable performance than their
chemical counterparts. For example, biologicals might reduce pest pressure, but not remove the pest entirely. Additionally, some biologicals
take longer to act on the target disease or pest, but their effects may be longer lasting.

By their nature biologicals are often pest- or disease-specific and cannot be used to control the broad spectrum of pests that attack
most crops. Additionally, once a pest is controlled, new pests inevitably occupy the ecological gap and may still require combat solutions –
chemical or otherwise. In short, biologicals are more effective when used as a component of integrated pest management (IPM) systems.

The economics of biologicals
There are several cost-related issues that also impact the acceptance of biologicals. Some present considerable manufacturing challenges.

Chemical Weekly October 22, 2024 125

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