Question
Can you diagnose browning or yellowing leaves on rosebushes?

Answer
Without seeing the leaves all I can tell you is that yellow leaves falling from the bottom of the bush may simply means the rose is getting rid of the oldest foliage. Leaves falling from the top means lack of water or high temperatures have put the rose under stress. Many times it is just that the temperatures are too high for the rose is under stress. When the weather cools down, the roses will start to come back and grow normally.