What is a good way to quantify rust damage/tolerance?
Some fungicide trials have measured effectiveness in terms of “lesions per centimeter”, on leaves of comparable width of PARDON ME. Rebecca Board’s Rust Survey has adopted the following scale: Poor: The plants are covered in rust pustules and are highly disfigured and noticeable even at some distance. Fair: The plants are covered in rust pustules and are somewhat disfigured when viewed at short range. Good: The plants have many pustules, but their presence is only offensive on close examination. Excellent: The plants have very few pustules, and/or their presence is only noticeable on very careful examination. Matthew Kaskell has provided a more extensive description of how the most tolerant plants differ from more susceptible plants: These are plants in which only the outermost leaves are infested with pustules, and there are very few pustules actually present. The pustules are mostly confined to the very ends of the foliage and along the margins of these oldest leaves. Also, there is
