Effects of Photo-selective Shade Net Color and Shading Percentage on Reducing Sunburn and Increasing the Quantity and Quality of Pomegranate Fruit

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 (۲۰۱۹ and ۲۰۲۰). 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 (۳۰ and ۵۰%) compared to uncovered plots (control) at Saveh region in the same orchard at the time of fruit set (۱۰ 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 ۲۷.۸۵ %, whereas in shade treatments, the percentage of sunburn was at ۰ - ۴.۵%. The white shade net ۵۰% 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 (۵۵.۱۳ mg/۱۰۰ mL), total phenolics (۳۴ mg GAE/۱۰۰ mL) and vitamin C (۲۱.۳۲ mg/۱۰۰ mL) was observed under white shade net ۵۰% PAR.

کلیدواژه ها:

Anthocyanin ، aril ، Canopy ، sun damage