Drooping leaves

I’m growing Blueberry x White Rhino and everything is going fine. I am using a light regimen of 19 hours on, five hours off. About three hours before the lights go out the leaves start to droop. Is this a genetic thing or is there something lacking in the air?
Lampmank, Saskatchewan

The leaves are drooping to protect themselves from the light. The reason is that the plants are being grown in small containers and the roots cannot grow enough to support the top part of the plant. A few hours before darkness they are pooped and use the dark period to recover.

The solution is to re-pot the plants into larger containers. The roots will quickly colonize the new medium and will be able to support the plants now that it has a larger infrastructure. Plants can flourish under continuous light during the vegetative cycle so long as the temperature is in the desirable range, and their nutrient needs are met.

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