What is a disadvantage of both capital EC and ULV formulations?

The disadvantage of both capital EC (Emulsifiable Concentrate) and ULV (Ultra Low Volume) formulations lies in the fact that solvents used in these formulations can indeed cause deterioration in rubber or plastic components. This is significant because many agricultural and pesticide application equipment components, such as seals and hoses, are made from these materials. If the solvent interacts negatively with them, it could lead to equipment failures, leaks, or reduced efficacy in application, which can compromise pest control efforts.

Understanding how these formulations behave when in contact with various materials is crucial for applicators to maintain their equipment and ensure that pesticide application is safe and effective. This aspect highlights the importance of proper maintenance and selection of materials when using these types of pesticide formulations.

In contrast, the other options relate to qualities that do not inherently act as disadvantages for both types of formulations. For instance, a longer shelf life is generally considered a benefit, and the need for more frequent applications is not directly tied to the nature of EC or ULV formulations but rather influenced by the target pests and application conditions. The idea that they are more effective against moisture tends to imply an advantage rather than a disadvantage. Thus, option B accurately captures a common drawback associated with these specific pesticide formulations.