What is a Biopesticide?
Biopesticides, a contraction of ‘biological pesticides’, include several types of pest management intervention: through predatory, parasitic, or chemical relationships. The term has been associated historically with biological control – and by implication – the manipulation of living organisms.
Biopesticide Controls of Plant Diseases
The need to feed an ever-growing global population combined with increasing demand for sustainable agricultural practices has fuelled a significant rise in demand for biopesticides. Biopesticides offer unique benefits all along the food value chain, providing additional options for growers, buyers, dealers, consultants and retailers. While biopesticides have been around for more than 50 years, the market has experienced its most significant period of growth in terms of both sales and user acceptance over the past five years. The use of biopesticides has become a common practice in many horticultural crop protection programs. Biopesticides are effective tools in integrated pest management (IPM) programs for helping to manage resistance to synthetic chemical pesticides and reduce worker and environmental exposure to synthetic pesticides. Multiple studies have documented the development of resistance by pathogen and pest populations to chemical pesticides. Conversely, the risks of developing resistance to biopesticides are extremely low – even as biopesticide use continues to increase.
Biopesticides Offer Significant Benefits to Growers
Managing pests in ways that leave little or no toxic residues, have minimal impact on non-target organisms, and are not prone to pest resistance has always been a challenge in modern agricultural systems. Additionally, enhancing product quality, residue management, labour and harvest flexibility and worker and environmental safety are all challenges growers face. Consumers are becoming more aware of environmental concerns and are asking for chemical-free crops. Nearly all biopesticides are most effectively used as preventive treatments. Since they deploy multiple Modes of Action (MOAs) to suppress pests and pathogens, development of resistance to these multiple factors by target organisms is extremely unlikely. Combinations of two or more of the characteristics described below prevent the development of resistance to biopesticides.
Aratibiotech biopesticides’s approach places principal emphasis on primary research techniques to ensure that the foundation of business intelligence and insight is accurate, current, and reliable. Building on our decades in the science, innovation and leveraging our national research institutes network cum international scientists . Our teams of seasoned professionals draw upon pragmatic industrial and commercial experience to understand and interpret global impacts and local perspectives to agriculture and speciality pesticides.
Aratibiotech Biopesticides Technologies
- Microbial species, such as fungi, viruses, or bacteria, acting as pesticides Production of antibiotics and other growth inhibitors- (Bacillus spp., Pseudomona spp., Trichoderma spp., Gliocladium spp., Streptomyces spp., etc)
Parasitism/Predation – Coniothyrium minitans (Parasite of Sclerotinia spp.) Trichoderma spp.
( Parasite of numerous soil borne fungal pathogens) – Bacteriophages ( Viruses that infect and lyse bacteria) – Paecilomyces spp. (nematophagous and entomophagous species) etcs
- Natural materials with pesticide properties, such as diatomaceous earth, kaolin etcs.
- Plant extracts, such as seaweed, neem, pyrethrum, oils and others as appropriate
- Biological seed treatment, including a cross-section of technologies used as protectants and stimulants.
Modes of Action (MOA) Aratibiotech Biopesticides®
- Competitive exclusion: Many microbial biopesticides not only grow very effectively in the environments from which they were originally isolated, they can also physically occupy these niches to prevent establishment of pests and pathogens in these spaces. If these microorganisms grow well on plant leaves or in close association with plant roots, they can also provide host plants with a protective barrier against pathogens and certain pests.
- Production of secondary metabolites: Since bacterial and fungal biopesticide strains are isolated from very competitive environments, each produces numerous secondary metabolites for protection, survival and competition for nutrients.
- Predation and parasitism: Some biopesticide agents physically attack and completely consume specific pathogens and pests. Other biopesticide agents actually act as parasites that feed on detrimental organisms, leading to weakening and eventual death.
- Induced host resistance and enhancement of plant vigour: Certain microorganisms used as biopesticides can stimulate subtle biochemical responses in host plants that enhance their abilities to resist or better tolerate pest attack and diseases. In addition, certain microbial biopesticides can also promote plant growth or enhance plant vigor by production of particular secondary metabolites and increasing availability of plant nutrients.
- Alteration of the soil or plant host environment: Biopesticides made from soft chemicals or biological extracts chemically or physically change conditions in the soil or on plant surfaces to be unfavorable to the establishment and growth of pests and pathogens.
- Disruption of fundamental biological functions, development, and structures of target organisms: Biorational chemicals and biological extracts can directly inhibit biochemical processes, interfere with developmental pathways of pathogens, and compromise the physical integrity of pests and pathogens. Because of the nature and diversity of the MOAs presented above, plant pathogens and pests would need to undergo immense physical, biochemical, physiological, and genetic changes to develop resistance to biopesticides. Therefore, the loss of effective biopesticides due to development of resistant pests and plant pathogens is highly unlikely.
Key for success
- Not curative!
Need to be used in a preventive manner.
- There are no silver bullets.
- Biopesticides need to be integrated with other pest management strategies.
- Pathogen identification!
Proper diagnosis is key to controlling any disease.
Advantages – No harmful residues produced, i.e. biodegradable. Can be cheaper than chemical pesticides when locally produced. Can be more effective than synthetic pesticides in the long-term (as demonstrated, for example, by the Sesame Crop cultivation programme, see below).
Disadvantages. High specificity: which may require an exact identification of the pest/pathogen and the use of multiple products to be used; although this can also be an advantage in that the biopesticide is less likely to harm species other than the target. Often slow speed of action (thus making them unsuitable if a pest outbreak is an immediate threat to a crop).
Plants are not defenseless. The difference between resistance and susceptibility is due to
the timing of pathogen recognition and the expression of defences.
- Aratibiotech Biopesticides® Formulations
Biopesticide products fall into two major categories: microbial and biochemical. Within each of these, there are various types of products, each with its own mode of action.
MICROBIAL – In this category, the active ingredient is a microorganism that either occurs naturally or is genetically engineered. The pesticidal action may be from the organism itself or from a substance it produces. The following microorganisms are used in microbial biopesticides:
- Bacteria- Biopesticides based on bacteria have been used to control plant diseases, nematodes, insects and weeds. They control pests in a number of ways: by producing toxins outcompeting the damaging pathogen, producing anti-fungal compounds and by promoting root and top growth. Bacillus thuringiensis (Bt), which targets larvae and Pseudomonas syringae, which controls bacterial spot are examples of microbial.
- Fungi – Fungal biopesticides are relatively new. They may be used to target nematodes, mites, insects, weeds or other fungi. Like bacteria, they may act by out-competing the targeted pathogen or producing toxins. They may also attack and parasitize plant pathogens or insects. Trichoderma harzianum is a fungi that is also a fungicide, targeting Pythium, Rhizoctonia and Fusarium
- Nematodes – Nematodes are colourless roundworms. Many are parasitic to plants and cause serious damage to crops. However, some are actually beneficial, attacking insect pests. The two main nematodes used for biopesticidal purposes are Steinernema spp. and Heterorhabditis spp.
- Protozoa- Protozoa are single-celled organisms that live in both water and soil. While most protozoa feed on bacteria and decaying organic matter, many species are insect parasites. In particular, one species of protozoa, Nosema locustae, is used to control grasshopper, locust and crickets on rangeland.
- Viruses – Microbial biopesticides known as baculoviruses are a family of naturally occurring viruses known to infect only insects and some related arthropods. Most are so host-specific that they infect only one or a few species of Lepidoptera larvae, which makes them ideal for management of crop pests with minimal harm to beneficial. The granulosis virus of Cydia pomonella, the codling moth, and the nuclear polyhedrosis virus of Heliothis/ Helicoverpa spp., the corn earworm, are two examples.
- Yeast – Some yeast species that naturally occur in plants have been developed into products that help to control postharvest decay and/or stimulate the plant’s immune system. For example, Candida olephila Strain O, first isolated from Golden Delicious apples, has been developed into an effective biopesticide for the control of post-harvest fruit rots.
Application rate: ratio 1:4 Litres ARATI Biopesticide® is a broad based spectrum
BIOCHEMICALS – Biochemical pesticides are naturally occurring or synthetically derived compounds that are structurally similar (and functionally identical) to their natural counterparts. Unlike conventional chemicals, which usually directly attack and kill the pest, biochemical biopesticides are characterized by a non-toxic mode of action that may affect the growth and development of a pest, its ability to reproduce, or pest ecology. Biochemicals might also be used to effect the growth and development of treated plants and their fruit, including during the postharvest period.
Application rate: ratio 1:4 Litres OTAI Biopesticide®
- Insect growth regulators – Prevent insects from reaching the reproductive stage.
- Feeding deterrents – are compounds that, once ingested by the insect pest, cause it to stop feeding. Crop damage is inhibited and the insect eventually starves to death.
- Repellents – are typically compounds that release odour’s that are unappealing to insects. Examples include garlic or pepper based insecticides.
- Confusants – imitate food sources and are used as traps or decoys to lure insects away from crops. They can also be formulated as concentrated sprays designed to overwhelm insects with so many sources of stimuli that they cannot locate the crop.
- Allelopathy – Some plants naturally produce biochemicals to prevent competition from neighbouring plants. Juglone, the allelochemical produced by black walnut trees (Juglans nigra), is toxic to many other plants. Many recently discovered allelochemicals have potential for development as natural product herbicides.
- Plant Growth Regulation – Some plant extracts can act as effective contact herbicides through a variety of mechanisms such as disrupting cell membranes in plant tissue, inhibiting amino acid synthesis or enzyme production.
- Mechanical Control – Some plant extracts are powerful natural agents that act directly on weeds.
D-limonene, for example, is a degreasing agent that strips the waxy cuticle from weed leaves, causing necrosis, dehydration and weed death.
- Fungicidal Control – By disrupting cell membrane integrity, deactivating key enzymes and interfering with metabolic processes, plant extracts can act as contact fungicides.
- Induced Resistance – Crops treated with some plant extracts produce and accumulate elevated levels of specialized proteins and other compounds that inhibit the development of fungal and bacterial diseases. In effect, the crop’s immune system is triggered to defend against destructive diseases.
Pheromones – Insects release chemical signals, called pheromones, to communicate with others in their species for a variety of reasons. These might include finding a mate, warning others of potential danger or
indicating the location of a food source. By using synthetic pheromones that mimic the action of the pests’ natural chemical, growers can disrupt mating cycles or lure pests away from crops. Each year, more than one million acres worldwide are treated with pheromones to control insect damage through mating disruption. Pheromones are also used in traps, allowing growers to predict insect populations and time application of controls.
- Minerals – Minerals play a key role in a wide range of biopesticide applications that can be divided into three categories:
- Barriers – act to keep pests away from plant tissues and/or impact pathogen water supply. An example is kaolin clay, which acts as a repellent that coats the plant surface, making it unsuitable for insect feeding or egg laying.
- Smothering and/or abrasion – one example is diatomaceous earth, which contains fossilized microscopic plants, giving the compound a sharp surface that cuts through insects’ exoskeletons, a process that leads to desiccation of the insect. Mineral oils are often used to smother insects in the nesting or crawler phases.
- Carrier for other biopesticides – minerals are also used as inert carriers for companion biopesticides. In these applications, minerals are included in formulations to deliver or enhance pest control agents, but the mineral itself is considered inert. Talc, kaolin, montmorillonite and attapulgite are just a few.