Effects of the modification of light intensity by color shade nets on yield and quality of tomato fruits

The photoselective netting concept was studied in a tomato 'Vedeta' cultivation in the south part of Serbia (Aleksinac) under high solar radiation, using four different colored shade-nets (pearl, red, blue and black) with different relative shading (40% and 50% PAR). Exposure to full sunlight was used as a control. Red and pearl nets with 40% shade significantly increased the total yield. Shading reduced the appearance of tomato cracking and eliminated sunscalds on tomato fruits and accordingly, increased the marketable tomato production by about 35% compared to non-shading conditions. Changing the light intensity by color shade nets affected the biosynthesis of lycopene and beta-carotene in tomatoes. Thus, significantly higher lycopene content was observed in greenhouse tomato integrated with red shade netting technologies (64.9 mu g g(-1)) than in field-grown tomatoes (48.1 mu g g(-1)). By contrast, shaded fruits have lower content of beta-carotene. The photo-selective, light-dispersive shade nets appear as interesting tools that can be further implemented within protected cultivation practices. (C) 2012 Elsevier B.V. All rights reserved.