The damage seems to be linked to a specific time or time span event: all the damaged leaves seem affected as they unfurled, but only specific parts that indicated simultaneous "exposure". I can't say if it is environmental or biological. For instance, it could still be bugs if the population had proliferated and then gotten wiped out, and normal growth occurred before the pics were taken. Perhaps you can link the damage to a specific weather condition or topical application?
This pic was taken 36 hours after application of a commercial mixture called Liquid Iron, that contains iron, copper, boron, zinc, manganese and magnesium. I use it on my elongating martagons (without detriment) when they show deficiency symptoms during excessively wet periods. This particular application, I thought I would see how other types of lilies might react. Since I did apply in the very early morning, and it was a very strong sunny day, I suspect the timing of the application was at fault, rather than the product itself. The martagons were not affected with that same application, but their growth has already slowing compared to this fast growing asiatic.
