blossom drop on my indoor grow-out New Big Dwarf?

[cleo88]

Hi,
I am growing two plants indoors that I started from seed in late November. The plants are 2 to 2 1/2 feet tall now. Once is a German Lineage which is a dwarf paste, and the other is New Big Dwarf.

German Lineage is doing great - I have two fruit so far (still green) and some flowers that are looking very promising (which I flick every day for pollination - I don't have a fan going). The NBD, however, has had some lame looking little flowers, perhaps even a bit deformed, and they've all fallen victim to blossom drop. Since the two plants are growing under the same conditions, it's not obvious to me what the NBD wants.

The temperature is in the low 70s during the day and probably similar at night. They are in a "grow closet" - mylar blankets on all walls and ceiling. They are in 5 gallon containers with Miracle Gro potting mix. I water from the bottom about every 4 days. The hygrometer says 29%.

Any ideas?