You will get a lot of new growth lower down thats normal,alot of people top their plants to encourage them to bush out but i wouldnt with yours at that size as you may struggle to get it to fruit.Are the leaves getting scorched?
Sorry, never saw your reply originally, but back again with another problem.
They have all grown fairly well and flowering plenty. Had a few chill's of the Thai plant, but my two nagas are really struggling.
They seem to be really quite healthy, had a good growth spurt since my last post and are covered in flowers. But once the flowers open they drop off after a few days.
I know they do this if they don't get pollinated, so have tried to help them along by moving the pollen around myself between flowers. The trouble is, they don't seem to be producing any pollen.
On my Thai plant if I rub the anther with my finger I can see plenty of pollen. But not the same on my naga's, they seem to be dry as a bone.
As there are no other signs that they are unhealthy in any way I don't think they are lacking nutrients. Looking online I found a suggestion that plants may not produce pollen if the humidity is too low. So I spent six weeks with them in the mini greenhouse putting in a bowl of boiling water every day and mist spraying the plants. There was a regular condensate on the inside if the greenhouse suggesting that humidity was pretty high but there is no change.
They are back indoors now on the window sill, still flowering and then dropping. Can they just be duff plants?