Chlorophyll content in beet cv. Early Wonder under nitrogen fertilization

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.