Tomatoes need at least 6 hours of direct sunlight to flower. Slender, non-fruiting tomato vines are a common complaint of home gardeners and are usually traceable to shading. Many homeowner and grower complaints can also be attributed to high or low temperatures. Malformed fruit are sometimes said to be 'catfaced' or to have open locules. These malformations are the result of incomplete separation of cells during the early stages of flower and fruit development.
Adverse effects seem to be worst when both day and night temperatures are high or when both are low.
Proper coloring of the fruit is also temperature dependent. 85 degrees F and lycopene is not synthesized below 50 degrees F, precluding normal color development in ripening fruit. Location of Production By acres harvested in 1992 in the United States, the top states for tomato production were California, Florida, Ohio, Indiana, and Michigan. May. Twenty percent of the fresh tomatoes consumed in the U.S. are imported. Of the total acres of both processing and fresh market tomatoes harvested in the United States, 11.2 percent are in the Southern Region.