When you ask about "major areas of production," I assume that you are asking about industries rather than about geographical locations.
New Jersey has a very diverse economy. The state is among the leaders in the US in various agricultural commodities. It is, for example, the second leading producer of blueberries. New Jersey has a very strong pharmaceutical industry. It also is strong in other areas that are related to chemicals such as detergents and industrial plastics. The second most important area of industry is food production. The third is the manufacture of electronics.