I have a silver leaf poplar that in the last two weeks has started to loose it's leaves. The leaves have tiny orange dots on them, then turn brown around the edges and fall. It has spread quickly. Do you know what this is or have suggestions on what I should do? I can send a picture of a leaf if I need to. Thanks!

Poplars are very susceptible to cankers, leaf beetles, scale, and slime flux. Because of these weaknesses, planting poplars is generally not recommended because they will tend to be so short lived. It sounds to me like you will be taking it out soon...