Biological Antagonism: A Safe and Sustainable Way to Manage Plant Diseases

Abstract

Biological control is a viable alternatives to the use of synthetic chemicals for plant pathogens management,., based on application of microbial antagonists as biological control agents (BCA). Plant health is significantly affected in many ways by a wide variety of pathogens. Cross protection, predation, hyperparasitism, induced resistance, antibiosis and competition are different mechanisms used by BCA. Knowledge is required for successful application of biocontrol in intensive management approaches. BCA can be applied at the site of infection directly or in each crop year, at sites in which they will multiply and spread to other field parts. To keep pathogen populations below economic threshold levels, occasional or one time applications can be adopted. However, due to different environmental conditions, biological control has not always produced encouraging results. To improve the BCA performance in the field, work on formulations is needed. For marketing, strains with better adaptability and field survival should be prospected. Most of biological control work has been centered on management of soil borne or seed borne pathogens. Most of the products containing BCA are applied as seed treatments for protecting major crops such as wheat, rice, sugar beet, corn and cotton. BCA are also used in foliar sprays to manage downy and powdery mildew, leaf spot and blight. Antagonistic microorganisms have also been used against few post-harvest pathogens. In spite of all significant improvements, this area still needs due consideration for developing more reliable and stable formulations, especially when for field applications. In this view, more research is required on innovative formulations by exploring novel microorganisms, using nano- and biotechnologies for their improvement, studying the impact of environmental conditions and the mass production of BCA. With a growing of biocontrol demand by growers, the future outlook of biocontrol is bright. By improving biocontrol research it is possible to completely replace chemical pesticides by BCA, improving yields, protection technologies and the environment, leading to a more sustainable agriculture.