To me it does not look like either of those diseases. The symptoms suggest a problem when those affected leaves were still in the whorl of the plant. I have seen similar symptoms following mild bacterial infections in the whorl of young maize during very wet weather. The affected leaves grow out and are normally followed by healthy growth. The amount of soil in the leaves and washing of soil around one of the plants shown suggests there had been very heavy rain previously.

Bob Fullerton
Principal Scientist

Posted on user's behalf

There does appear to be some minor insect damage with loss of green leaf material from rasping or chewing on under-side of leaves, but this looks minor and old damage. But insect damage can lead to secondary bacterial infection. The heavy rain may also have killed insect pests so you don’t get major leaf cutting and/or leaf collapse from damage by, for example, large caterpillars. So, I think mainly disease ‘infection’ after very heavy rain, in other words, not primarily insect damage.