Recent Trends in Plant- and Microbe-Based Biopesticide for Sustainable Crop Production and Environmental Security

The impact of increasing human population, rising food demand, and adverse effects of climate change, viz., changing rainfall pattern, rising temperature, biotic-abiotic stresses, etc., has tremendously affected global food security. In addition, increased anthropogenic inputs from urbanization, industrialization, as well as outrageous use of chemical fertilizers and pesticides have posed a severe threat to the sustainability of the agroecosystems. For many decades, the use of chemical pesticides against insect and microbial pests has become an integrative part of agriculture and contributed significantly to the crop improvement. But, their long-term persistence, cytotoxicity, and microbial resistance have resulted negative impact on the biosphere, thus creating pollution of diverse ecosystems, land degradation, and biodiversity losses. For the last two decades, alternate pest management strategies have become the new avenues for controlling pest and diseases in a greener, safer, and eco-friendly manner. The use of biological control agents (termed as biocides) such as both microbe- and plant-based formulations has been known to be the major emerging tool in crop disease/pest management and appealing alternative to the chemical pesticide in sustainable agriculture. Biopesticides employ the use of naturally occurring substances, i.e., living organisms (natural enemies) or their products (phytochemicals, microbial products) or by-products (semiochemicals) that control pests by nontoxic mechanisms, with high targeted activity against causal agents (insects, fungi, weeds, viruses, nematodes, etc.), and nonpersistence in the environment. The use of biopesticide alone or in combination with agrochemicals has become the new tool in crop protection as a part of biointensive integrated pest management (IPM) strategies. Although biopesticides are slowly substituting the chemical pesticides with great promise, its use to the desired extent is lacking; hence insight on such biological agents is a prerequisite. In this chapter, we have summarized the sources of biopesticides, their plant protective mechanisms (mode of action), availability, and status in India, as well as some critical pros and cons of its use.