GROWTH AND OIL CONTENT OF BASIL (Ocimum basilicum L.) GROWN UNDER COLORED SHADE NETS

In agrotechnology, colored shade nets are proposed as a strategy to improve the effect of solar radiation on plants. This study evaluated the growth, physiology and oil content of basil plants (Ocimum basilicum L.; 'Nufar F1' Sweet Genovese) grown under colored shade nets. The plants were grown under polyethylene nets with a shade coefficient of 50%; different colors were considered different treatments: red, blue, pearl, black and control (no net). These treatments were distributed in randomized blocks with three replicates. Microclimatic variables, plant growth and physiological parameters, and oil content were recorded. Photosynthetically active radiation (PAR), integrated photosynthetically active radiation (IPAR) and temperature were lower than in the control treatment, regardless of the color of the net, and relative humidity was higher. The black net increased plant height and reduced dry weight, stem diameter and number of buds. The highest dry weight of leaves and inflorescences, as well as the highest CO2 assimilation rate, were obtained with the red net and the control: 22.44 and 23.17 mu mol CO2/m(2).s, respectively. The highest content of oil ranged from 0.6 to 0.7% with the red, pearl, blue and control treatments; however, the content of oil decreased by 34.3% with the black net treatment compared with the control.