The mercury dipped below the freezing mark throughout South Jersey Tuesday morning, but farmers reported little or no crop damage. The State Department of Environmental Quality announced Monday evening that it would allow farmers to use open burning and “smudge pots” in fields to help save crops as necessary. Due to unseasonably warm winter and early spring weather, crops have grown much earlier than normal and are at a greater risk for damage from freezing temperatures. The official low for the region was 29 degrees at the Atlantic City Airport in EHT.