**6. Effect of pre-sowing herbicides on weed control of maize**

Generally, pre-sowing/planting herbicides are non-selective which are applied to control prevailing complex annual and perennial weeds flora erstwhile to planting, particularly under the CA-based cropping system. Among them, herbicide Glyphosate (1 kg ai ha<sup>−</sup><sup>1</sup> or 0.5–1.5% by volume), Glucofosinate, or dicamba and Paraquat (0.5 kg ai ha<sup>−</sup><sup>1</sup> or 0.5% by volume) are the most widely applicable herbicides [52, 53]. Where Glyphosate and Paraquat herbicides are available and popular as these are systemic non-selective and contact herbicides, respectively, and kill both annual and perennial weeds. To be effective, the systemic (Glyphosate) should be applied when weeds are growing actively so that the herbicide is absorbed and translocated into the entire plant system [17], but contact herbicide (Paraquat) can be applied just before the sowing.

Currently, the present rates of many herbicides do not work properly against many weeds, due to their resistance against the target weeds. Therefore, it is important to apply a new product to be available earlier than normal in order to maximize the contribution of residual weed control after crop emergence. The earlier study found that if the pre-sowing herbicide is applied before planting and is incorporated in the soil with light tillage, the efficacy of the applied herbicides was found the maximum [54].
