Start with what you can show: crop and stage, date first noticed, number or area affected, location, recent operations and whether the pattern is spreading. Photograph a whole-room view, an affected area, an unaffected comparison and a close detail.
A brown mark, slow patch or unusual shape can have more than one explanation. Record relevant material lots, watering, environment and insect observations. Keep the distinction between “I saw this” and “I think this caused it”.
Follow the farm’s containment procedure while seeking qualified advice. Do not open suspect material just to smell it, move it through clean work, or choose a pesticide from a photograph. A specialist may require samples, records or testing before recommending action.