Use of Natural Products for Weed Management in High-Value Crops: An Overview

Over the last five decades, weed management systems have relied primarily on synthetic herbicides. Due to the concerns over the potential impact of chemicals on human health and the environment, efforts are being made to reduce the heavy reliance on synthetic herbicides. To reduce the use of synthetic herbicides, the use of natural products such as essential oils, plant extracts, allelochemicals, agricultural by-products, and some microbes are gaining attention because of their short environmental half-life and low toxicity. They are a good alternative to synthetic herbicides, especially in organic agriculture, since they focus on environmental protection, and ecological stability. Most of the commercially available natural herbicides are non-selective and require careful application in order to preserve the cash crops. Although many studies in this direction have been undertaken, the use of these natural products is still not common because of their cost the difficulties in their synthesis due to their complex structure, cost effectiveness, poor performance, and rapid degradation. When used singly, these natural herbicides do not perform as well as the chemical herbicides. An integrated approach may provide better results. Using a combination of natural herbicides may be more effective than using just one.