Document Type : Research paper
Authors
1 Crop and Horticultural Science Research Department, Markazi Agricultural and Natural Resources Research and Education Center (AREEO), Arak, Iran. E-mail address: v.narjesi@areeo.ac.ir
2 Citrus and Subtropical Fruits Research Center, Horticultural Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Ramsar, Iran.
3 Nuclear Agriculture Research School, Nuclear Science and Technology Research Institute (NSTRI), Karaj, P.O. Box 31485498, Iran
Abstract
A prevalent problem in pomegranate fruit is sun damage that decreases the quantity and quality of fruit. This study's objective was to evaluate the effect of different photo-selective shade net colors and shading percentages on growth traits and pomegranate fruit quality during two-years (2019 and 2020). Plots of pomegranate trees (cv. Malse Saveh) were covered to full canopy with two colors photo-selective shade nets (White and Green) and with two shading percent (30 and 50%) compared to uncovered plots (control) at Saveh region in the same orchard at the time of fruit set (10 June) and maintained on the trees for four months. The findings showed that shade nets increased relative leaf water content while decreasing temperature and light intensity in the canopy and fruits as compared to the control. Pomegranates maintained under nets had much higher fruit weight and yield than those uncover trees. The percentage of sunburn fruits was dramatically reduced when a shade net was used. In uncovered trees, the percentage of sunburn was 27.85 %, whereas in shade treatments, the percentage of sunburn was at 0 - 4.5%. The white shade net 50% PAR (Photosynthetically active radiation) had the highest fruit weight, juice percentage, aril weight and yield, maximum color of fruits and arils, as well as the lowest level of proline content among the shading treatments. The highest amount of total anthocyanin (55.13 mg/100 mL), total phenolics (34 mg GAE/100 mL) and vitamin C (21.32 mg/100 mL) was observed under white shade net 50% PAR.
Keywords
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