Under what condition can a crop hail application be considered invalid?

A crop hail application can be considered invalid if it is not signed by the insured because a signature signifies the insured's agreement to the terms and conditions of the insurance policy. Without this signature, the application lacks the necessary authorization to bind the insurer to the coverage requested. This is crucial as it ensures that the person applying for the insurance is indeed consenting to the coverage and understands the implications involved in the policy.

The other conditions, such as late submission, submission without payment, or submitting an application for a crop that has already been harvested, typically have their own sets of implications but do not fundamentally invalidate the application like the lack of a signature does. For instance, late submissions might lead to rejection based on timing, and submitting without payment could prevent coverage from taking effect, but these scenarios do not negate the validity of the application in the same way as an unsigned form does. The absence of a signature directly undermines the binding nature of the agreement between the insurer and the insured.