Photo-selective netting for improved performance of tomato fruit

Under high solar radiation conditions throught 900 W m^-2 (in South Serbia at July and August) and value of photosynthetic photon flux density (PPFD) over 1600 μmol m^-2 s^-1, unshaded plants were exposed to high heat stress throughout the growing season. The photo-selective netting concept was studied in tomato (Solanum lycopersicon LSQUOVedettaRSQUO) cultivation in different colored shade-nets (pearl, red, blue and black) with 40% relative shading, applied by itself over net-house constructions, or combined with plastic tunnels technologies. The shading of tomatoes resulted in a number of changes on both, local microclimate (intensity and radiation spectrum) and structure of tomato fruit parameters. Tomato from pearl nets with 40% shade obtained the largest part of the fruits as pericarp (81.38%), locular gel tissues (16.19%) and seed (2.43%) of total fruit mass. Statistically significant differences were determined in the percentages of mesocarp and gelatinous mass between treatments. Number of seeds (208) and mass (5.4 g) is usually very significantly higher under red net house. Pericarp thickness (egzocarp-126.37 µm, mezocarp-7055.47 µm and endocarp-33.98 µm) was significantly higher in pearl (7.215.82 µm) and red (7099.00 µm) color nets compared to other treatments and control-open field tomato (6202.48 µm). These results show that shade application of color nets to tomato plants was effective in substantially improving tomato fruit structure parameters and the obtained data can be used to create optimal growing conditions to achieve the fruits with thicker pericarp, firmest and better tolerated transport and storage.