This study aimed to evaluate the effects of doses of nitrogen fertilizer in association with types of basal dressing fertilizers on the physiological characteristics of beet cultivar Early Wonder in a protected environment. The experiment was conducted in safe environment at the Federal University of Campina Grande, using a randomized block design with three replications and a 5x3 factorial scheme, in five doses of nitrogen (0, 50, 100, 150 and 200 mg dm-3) applied through fertigation, and three types of basal dressing fertilizers (unfertilized soil, earthworm humus and earthworm humus + NPK). At 45 and 90 days after transplanting (DAT), it was determined the chlorophylls a, b, total chlorophylls, carotenoids and SPAD index. Organo-mineral fertilizer (earthworm humus + NPK) provides greater efficiency for the photosynthetic pigments when compared with organic fertilizer (earthworm humus) and without fertilization (control).The increase of nitrogen dose up to 200 mg dm-3 is the one which contributes most to the increment of chloroplastid pigments. Nutrients were absorbed by the plants and the humus and humus + NPK treatments supplied the nutritional demands during the beet cultivation cycle.
Beta vulgaris L.; nitrogen; organic fertilization; intensity of green color.