Herbicides of biological origin: a review

Biological herbicides or bioherbicides can reduce the use of synthetic herbicides and minimise the negative environmental impact of them. To be successful, bioherbicides must have a competitive price, efficiency and consistency. In this review, the highest level of development, and the future prospects for herbicides of biological origin are reported and discussed. Application of bioherbicides allows the reduction of fertilisers and environmental contamination and, at the same time, increases the tolerance of plants to biotic and abiotic stresses, as well as, they are used to suppress weeds that are difficult to control and those resistant to herbicides. Another promising line of research in Brazil is the one that deals with bioherbicide based on phytopathogens, combined with adjuvants in a formulation that can increase herbicidal activity. Therefore, the development of new herbicides is of great importance, because the effectiveness of the commercially available ones is decreasing drastically, and the chemical control of weeds still remains the most widespread agronomic practice.