i was convinced i had tmv (thread here) but it wasn’t transferring to my other plants and when i increased feed by 100% for that plant all symptoms went away… could have been a PH problem which was corrected by the increased feed or maybe some deficiency
you can buy test kits which detects a variety of viruses from the tobamovirus group including sunn-hemp mosaic virus, i have never seen a case of suspected TMV actually test positive while researching during my previous scare, but only saw maybe 5 or 6 people that actually tested