Some context. I had some PPP growing and it was doing well. Then I overwatered and it sat in the dish with too much water for about 8 hours. Crowded plants and high humidity due to weather changes and limited response in the grow environment. (Not gonna be able to get to 55 RH with it raining in this ‘envelope’)
So soon noticed yellowing of a couple lower buds. Next leaves curling and drying as in the photo above. These plants have fully developed seeds and I was trying to ripen the rest of the flowers. Onset was particularly fast where seed development was finished or close.
Removing infected material did not seem to slow things down and it seemed to spread to other plants. Began removing material, thinking it might be botrytis initially. Disease spread. Removed infected plants and increasing air circulation. Seems as noted to spread to open wounds e.g. a leaf is pinched off. Will begin yellowing and the stem will get dark streaks there then spread to the rest of the plant.
Stronger healthy plants seem to be resistant. At the least the Appy leaner of the SSDD f3’s shows no sign atm.