Delicato Vineyards is asking voters if they trust Manteca Mayor Gary Singh as well as the city’s firefighters and police or the corporation with annual sales approaching half a billion dollars. It is part of extensive poll being conducted by Research-Polls in a bid to help the owners of the world’s fifth largest winery craft a targeted campaign aimed at torpedoing the updated general plan they had issues with because it doesn’t dictate how they want property that they don’t own to be developed.