Botanical-microbial Synergy—Fundaments of Untapped Potential of Sustainable Agriculture

Plant diseases must be controlled to maintain food supplies and sufficiently nourish the global population. Farmers often rely on synthetic pesticides to protect crops. Irrational use of conventional pesticides leads to detrimental effects on ecosystems including environmental pollution, harm to human health and development of bioagressor resistance. The remedy for these catastrophic ordeals lies in sustainable agriculture providing ecosystem services, including biological pest management using live organisms or natural substances. Botanical and microbial-based biopesticides are good choices for crop protection, protecting crops from the vast array of bioagressors in an eco-friendly manner using a range of mechanisms. Furthermore, they display several advantages over synthetic pesticides including target specificity, minor toxicity and biodegradability. However, major challenges hinder their commercial success. A promising approach in the context of developing novel effective biopesticides is to combine botanicals and entomopathogens. Combinations often display synergism, resulting in higher control of bioagressors at lower doses. Furthermore, the combination of agents with differing mechanisms of action help to delay resistance development in bioagressors. The combinations of botanical and microbial agents must be carefully designed to obtain synergistic formulations. Hence, choosing compatible agents, the right combination ratio and the appropriate application time and technique is essential. The efficacy of botanical and microbial combinations must be validated in in situ conditions, along with the investigation of their effect on beneficial non-target organisms. Incorporating novel biopesticides from a portfolio of botanicals and microbials into pest management advances research on biological control of bioagressors and accentuates expansive circularity of sustainable agriculture.