Which application method involves applying pesticides to plant stems or trunks at or just above ground level?

The correct answer pertains to the basal application method, which specifically involves targeting the plant stems or trunks of woody plants at or just above ground level. This application technique is particularly effective for controlling certain pests and diseases that reside at the lower portions of the plant, as it allows the pesticide to move into the plant system through the bark and into the vascular tissues.

Basal applications are usually performed with a diluted mixture of pesticide, ensuring that the plant absorbs the chemical effectively while minimizing the impact on surrounding areas or non-target organisms. This method is advantageous for treating larger plants or trees, as it directly targets the areas where pests are likely to enter or reside.

In contrast, other methods like broadcast application involve a wider spread of pesticides over a large area and are not focused on a specific part of the plant. Rope-wick treatment utilizes a wicking action to apply herbicides to the leaves, whereas wiper application generally involves wiping the pesticide onto the foliage rather than applying it directly to the base of the plant.