Picker is shrink on Windows Phone 8

Why is Picker shrinking on windows phone 8/emulator while the same code is displaying it well on android and iOS?

var orgsPicker = new Picker
{
Title = "Select One",
MinimumWidthRequest = 200,
HorizontalOptions = LayoutOptions.StartAndExpand
};

This displays the Picker like a vertical line; i.e. width is 1 pixel only.