One of my friend sent me this.It is a phalaenopsis. Plant did not show any symptom this morning, but now, this evening this happened. Backside of leaves are full of inmobile tiny white dots, leaves became wet and brown.Any idea?
Indeed, it looks like some type of bacterial soft rot. They can spread very, very, quickly overwhelming a plant.
Notice that these white dots are only where the rot appears! There has to be a connection.
It can be so hard to tell at times but in my experience, these “bacterial soft rots” can happen so quickly compared to fungal issues. Erwinia for example could kill a Phalaenopsis practically overnight.