Bio-herbicides: development, use and elucidation of the factors affecting their efficacy

Weeds belong to diverse groups of exotic and native grass species and are considered problematic for significant crops such as Cyperus rotundus or Dhela; Avena fatua or Jungli Jai are considered one of the most dangerous weeds of wheat around the world. The agricultural product loss recorded in Pakistan due to weeds are estimated a 17-25% yield loss in wheat due to weeds, 20-45% loss in maize, 13-41% loss in cotton, 20-63% loss in rice, 10-35% highest loss in sugarcane, and 25-55% in pulses. Many weeds inhibit the growth of other plants with their allelopathic effects through the release of specific inhibiting substances in the topsoil. Several weeds provide them as alternate host plants for various types of insects, pathogenic fungi, bacteria, and viruses that may attack the crop. To meet food demand in the increasing population in upcoming years is a big challenge in Pakistan. The first use of biological control of weeds was reported in 1971, the biological product used to control weeds was called bio-herbicide. It is eco-friendly, safe for non-targeted organisms, practically easy to use, and not involved in health-related risks of humans and animals. This review tried to explain the role of bio-herbicides in the control of weeds.