Microbial Phytotoxins as Sources of Herbicides: Current Development and Future Scope

Weeds are a problem in a variety of land uses, associated with declines in crop yields, quality and health nuisance. The herbicide resistance and chemical pesticides are the major issue for new generation due to strong support for developing a new novel compound to control weeds. Due to less user of chemical herbicide in current scenario, it is very important to develop a new class of bioherbicide with novel mode of action which is not previously developed. Development of ecofriendly weed control has shown a novel and innovative path to Scientist for developing a natural herbicide based on microbes. It is known that microorganism produce thousands of secondary products, many of which are phytotoxic and may potentially be used as herbicides or templates for the synthesis of new herbicides. The interest of researchers is therefore focused particularly on pathogen living on weeds. Microbial products are attractive candidate for potential use in agriculture. They are characterized by highly specific activity and high selectivity while at the same time they are readily biodegradable. They belong to very diverse groups such as polyketides, terpenoids, diketopiperasines, isocoumarins etc. of course, these compounds are too complex in structure to be used herbicide. However, secondary products of microorganism represent subject matter of wide research and supplement the organic synthesis in the development and extension of new biologically national and cost-effective herbicides. The potential microbial marasmin to control some noxious important weeds is reviewed here. The noxious weeds are Parthenium hysterophorus, Lantana camara, Xanthium strumarum, Cassia tora, Hyptis suveolens, Sida actua and Antigonon leptopus. It is concluded that of this weeds, best suited as targets for biological control using microbial metabolites.