Which herbicide formulation is known for thick consistency and is effective in reducing drift during application?

The correct choice is invert emulsions, which are specifically designed to have a thick consistency. This formulation consists of water droplets dispersed in an oil phase, leading to a more viscous product. The thickness of invert emulsions helps to minimize the risk of drift during application by providing improved adherence to plant surfaces and reducing the likelihood of droplets being carried away by wind.

Additionally, the properties of invert emulsions allow for better control during application, making it easier for the applicator to direct the herbicide exactly where it is needed. This quality is particularly advantageous in sensitive areas where drift could impact non-target species or neighboring crops.

The other formulations, while effective in various contexts, do not share the same level of viscosity or drift-reducing characteristics. Soluble concentrates typically comprise water-soluble substances that may become more prone to drift due to their liquid nature. Flowables can reduce drift somewhat due to their thicker consistency compared to concentrates, but they do not match the effectiveness of invert emulsions in this regard. Wettable powders require mixing with water to form a suspension and can also be more susceptible to drift compared to thicker formulations. Thus, invert emulsions stand out in their ability to effectively minimize drift during herbicide application.