BELL PEPPER PRODUCTION UNDER COLORED SHADE NETS

Abstract

Use of black shade nets is a strategy to protect plants from direct solar radiation, reduce temperature and avoid fruit sun scald in bell pepper cultivation (Capsicum annuum L.). In the last decade, colored nets became available in the market to improve utilization of solar radiation in protected crops, due to its photometric properties. This work evaluated the influence of five shade nets on transmission of photosynthetically active radiation (PAR), air temperature and relative humidity, plant growth and yield of bell pepper. Polyethylene nets with 50 % shading were used in green, red, beige and blue, as well as black as positive control, plus an unprotected treatment as a negative control. PAR transmission by colored nets ranged from 55.3 to 58.3 %, compared to 51.9 % by black net. Colored nets did not cause a significant reduction in air temperature, while relative humidity increased from 9.1 in the black net to 21.0 % in the beige net. Green and red nets caused the largest increases in plant height and leaf area. Export quality yield in unprotected control accounted for 20.4 t ha-1, while colored nets exceeded from 52.5 % in the black net to 132.8 % in the beige net. In unprotected control the yield of non-commercial fruits was statistically higher that in colored nets.