The energy crunch of the mid-seventies has adversely affected the greenhouse tomato industry in the North Central and Northeast regions. Traditionally, these two regions had been the main producers of greenhouse tomatoes in the U.S. where, because of the climatic restriction, greenhouse tomato production evolved to supply fresh tomatoes during winter and spring months. Since greenhouse producers in the north rely on fossil fuels for heating purposes, their production costs have escalated, thereby tending to price these tomatoes out of the market. In recent years many greenhouse tomato producers in the northern regions have either ceased production or switched into alternative enterprises. For instance, the Census of Agriculture reported 45 growers in Massachusetts in 1974, with covered areas of 535,842 square feet; by 1979, according to extension experts, the number declined to 25 and the area declined to between 150,000 and 200,000 square feet. The number of growers in New Jersey declined from 42 in the 1974 census to only 19 in 1979. Similar declines have occurred in New York and Pennsylvania.