Role of Biopesticides in Crop Protection: Present Status and Future Prospects
The sharp increase in the use of chemical pesticides in India in recent years has resulted in severe implications in the development of insecticidal resistance in key pest species, pesticide residues in food chain, degradation in the quality of ecosystem and human health. Microbials such as viruses, bacteria, fungi, protozoa, nematodes and plant products are the major biopesticides that were studied mostly to develop alternatives to chemicals. In India, biopesticide science is not anew tool and is as old as human civilization back to prehistoric days. Though biopesticides cover only about 1% of the total plant protection products globally, their number and the growth rate have been showing an increasing trend in the past two decades.
In recent years, ICRISAT in collaboration with National Agricultural Research and Extension Systems (NARES) in India have made significant progress in the identification, production and field evaluation of biopesticides. Understanding of ecology has increased to identify the potential problems to work on, the approach, when and where they have maximum impact. The virulence of various bioagents such as nuclear polyhedrosis virus (NPV), bacteria and plant products was tested under controlled conditions and the selected ones were evaluated under hot spots. Strategic research related to DNA of different HaNPV strains from India indicated their similarities with the presence of four major polypeptides with molecular weight ranging from 30.66-42.32 kilo Daltons.
There was significant progress in developing feasible production technologies, efficient storage to enhance the shelf life and filed applications. In this process ICRISAT trained several NARES scientists and farmers on biopesticide production and established 96 village level NPV production units in India and Nepal to encourage their use. On-farm studies in biopesticide front indicated 20-40% increased yields in pigeonpea and chickpea. Bio-intensive cotton 1PM crops realized 1-30% and vegetable farmers obtained 72% increased yields through better management of pests and augmenting natural enemies.
The overall goal of biopesticide research is to see that the products are made available at farm level at affordable cost, and that they overcome the existing bottlenecks so as to become potential tools in the armory: of plant protection. To ensure this, there is every need to strengthen the communication between researchers, industry and fanners. The biopesticide science is still young and evolving, hence in-depth research is needed in many areas such as production, formulation, delivery and commercialization of these products. On the other hand, more research is needed in integrating biocontrol agents into production systems, such as in sequencing biocontrol with other options and in developing these into forecast models for better timing of effective options.
More studies are also needed to determine the environmental effects on the fate of bioagents, new technologies such as micro encapsulation of bioproducts are of high priority in enhancing their potential. The present trends in research include the increased use of biorational screening processes to identify potential agents, evaluation under laboratory and filed conditions, emphasis on integrating these with other control methods in an overall system approach. Even though the organic products are considered less toxic it is important to be careful when using any pesticide and considerable precautions need to be taken while production, processing and utilization. Thus, this manuscript discussed various aspects of biopesticides covering the status, constraints, prospects, integration and the future strategies for their effective utilization to the benefit of human kind.
Biopesticides, status, crops, protection.