Review of the influence of major environmental and agronomic factors on the lycopene content of tomato fruit

Recent studies have focused on the role of antioxidants in the prevention of diseases such as cancer and cardiovascular diseases. Lycopene is one of the major antioxidants found in tomato fruit and derived products. Moreover, the lycopene content accounts for the red colour which is increasingly sought after by industry and consumers. The production of raw material rich enough in lycopene has become important. Lycopene concentration in tomato fruit may depend on genetics and consequently the choice of the cultivated variety may influence the result at harvest. In order to try to control lycopene content at the field level when growing a given variety, the influence of the major factors of environment and cultural techniques on lycopene content of tomato fruit must be known. Scientific papers from the last 50 years have been reviewed. Temperatures below 12 degreesC strongly reduce lycopene biosynthesis and temperatures above 32 degreesC stop it. Lycopene development is also increased by light, except for direct excessive sunlight. The influence of water availability and mineral nutrition (nitrogen, phosphorus, potassium) is presented and the results sometimes appear contradictory. Lycopene content increases sharply during the ripening period, from the pink stage onwards and may be influenced by plant growth regulators.