This fact could be attributed to two reasons, temperature and light quality. Significant differences are found among cultivars, and within cultivars cultivated under red or pearl
net (Thomas and Jen, 1975). As lycopene biosynthesis is mediated by phytochrome, slight variations in red light over mature-green fruit stimulates lycopene accumulation (Alba et al., 2000), which may explain the different lycopene content obtained depending on the net, red or pearl, under which tomatoes were grown.