I'm not sure without knowing your air temp and humidity, looks like you've got a controlled grow though and looks good, possibly the plants are focusing everything they've got on fattening those flowers up and the leaves are just in the way?
Hard to say for sure without more information. What kind of soil/media are you growing in, what's the watering/feeding schedule? Ppm/pH? Nutrients used? Light size/distance from plants, etc etc.
Just first impression with info given, looks like possibly overwatering.
they have more problems than watering issues looking at those foxtails, claws and structure of leaves and colour
but right now at week 9 of flower all you can do is survive to the end and do better next time