Biologicals in edible gardens
EPISODE 2 – Bio-pesticides in your garden explained
The goal of Sustainable gardening is to grow healthy nutrient-dense crops, in a healthy environment with minimal impact on the environment. Biopesticides offer natural, non-chemical alternatives. These may not be as immediate and as impactful as a synthetic pesticide, because they take a little longer to take effect. However, they are just as effective as their chemical counterparts and should be your first and ‘number 1’ option in your edible garden’s pest management program.
Natural biological control takes place continuously, in its own unique way within every eco-system. Using a garden as an example, biological pest control includes birds eating grubs; frogs eating insects; ladybirds (& others) feeding on insects and competitor plants out-competing others. However, it’s in the development of the beneficial micro-organisms – bacteria, fungi and virus’ that the most meaningful product solutions are emerging.
Several strains of fungi and bacteria have been identified to be effective in the control and management of pests and diseases. Each has a unique mode-of-action, for example:
- The spores of beneficial fungus Trichoderma asperellum are aggressive, fast-growing and quick to colonise root systems. They form a symbiotic relationship with plant roots out-competing and out-growing fungal pathogens. They also suppress and manage root diseases (i.e. Rhizoctonia, Phytophthora and another damping-off disease) parasitising the pathogen by coiling around its hyphae, constricting, penetrating and eventually destroying it.
- Beneficial bacterial Bacillus thuringiensis (Bt)is one of the most successful and widely used biological pesticides in agriculture. When ingested by pest larvae, the specific gut enzymes found in caterpillars dissolve a unique crystalline protein found in each Bt cell. This disrupts the pest’s digestive tract causing it to stop eating and ultimately to become paralysed and die.