BLC MALWORTH WHOLE LEAF ROTTING
 

This BLC Malworth "Orchidglade" has large brown spot destroying leaf. Spot feels tacky but not mushy. Root check showed more brown, soggy roots than green or white new roots --so repotted. Watering twice a week, 60% humidity, 1500 -2000 fc light and feed weakly weekly 20-20-20. New leafs are OK. Any ideas? Thank you. :)

Could it be sunburn? Especially possible if water was on the leaf acting like a lens. I'd remove the damaged part of the leaf leaving no brown at all and treat the cut with cinnamon.

Thanks. I have had sunburn similar to this on Cattleyas and never treated the leaf. Why not cut the whole leaf off?

Just cut the leaf to remove the brown area. Keep any remaining part of the leaf.

Yes. Just cut the brown/black part of the leaf off and dab the cut with cinnamon. I use a Qtip for that. Why are you watering twice a week? That seems like a lot and that is probably the cause of this bacterial brown spot (acidovorax). Don't water overhead as this spreads the problem. It is rarely fatal but will eventually kill the leaf as it slowly enlarges. It primarily attacks older leaves. Just cut off that portion of the leaf and treat with cinnamon.