First of all, make sure they are separate plants. If they are you can separate them into different pots. If they are not separate plants snip off the weakest one. If you don't the plants will always be getting in each others way competing for light, moisture and nutrition and not being a healthy productive tree. No, do not support the tree. Add a fan to blow air on the tree thus strengthening the tree. Supporting the tree at this age will actually weaken it.