Influência da adubação nitrogenada e da inoculação com Azospirillum na qualidade da Alface Americana cv. Lucy Brown

Abstract

The aim of this study was to evaluate the technical efficiency of Azospirillum application in iceberg lettuce cv. Lucy brown combined with nitrogen levels and its influence on qualitative parameters. The experimental design was DIC in factorial arrangement 2X4 with 4 repetitions. The treatments consisted of 2 modes (Inoculated and control) as well as four nitrogen rates (50, 100, 150 and 200 kg ha-¹). It was evaluated the leaf colorimetry with illuminant D65 in the L * a * b, saturation or chroma, Hue angle, besides the chlorophyll content. The results showed no significant different to mode, dose and the interaction between them. For the variable L * the lowest and highest value were 58.06 and 58.50 respectively to inoculated plants control. For nitrogen ratio, the highest value was observed at a dose of 50kg.ha -1 and the lowest in 200kg.ha-1 dose with 59.12 values and 57.37 respectively. For variable a* the lowest and highest value were -11.00 and -10.81 respectively inoculated plants and control. To nitrogen dose, the highest value was observed at the dose of 100 kg ha -1 and the lowest on the dose of 200 kg.ha-1 with -10.50 and -11.25 values respectively. The variable b * the lowest and highest value were 22.00 and 22.56 respectively inoculated plants without inoculation. Regarding nitrogen dose, the dose value for 50 and 150 kg ha-1 were equal and the lowest was in dose 100 kg.ha-1 with 22,75 and 21,62 values respectively. For relative saturation (Chroma) the lowest and highest value were 24.69 and 25.31 respectively in inoculated plants and control. To nitrogen dose was observed the highest dose of 150 kg ha-1 and the lowest dose at 50 kg ha-1 with 25,25 and 22,50 respectively. In variable Hue values were equal to 116.82 ° and 116.82 ° respectively inoculated plants without inoculation. As for the dose of nitrogen, the highes t value was observed at the dose of 200 kg ha-1 and the lowest dose at 50 kg ha-1 with 117.63 values and 116 respectively. For Chlorophyll content the lowest and highest value were 20.69 mg g-1 and 21.31 mg g-1 respectively in inoculated plants and control and nitrogen dose, the highest value was observed at a dose of 200 kg.ha-1 and the lowest dose 150 kg.ha-1 with values of 22.75 and 19.12 respectively. Azospirillum Inoculation associated with nitrogen fertilization did not alter the qualitative aspects of the sheet color and also in relation to the chlorophyll content in iceberg lettuce cv. Lucy brown.