The objective of this study was to evaluate the effects from N doses (0; 400; 800; 1,600; 3,200; and 4,800 mg/dm³ of N in substrate) on the growth of rootstocks lemons 'Cravo' and 'Volkameriano', tangerines 'Cleópatra' and 'Sunki', and hybrid 'Tangelo- Orlando' grown in tubules conditions. According to the results, the lemons presented a greater growth, the tangerines presented intermediate growth and the hybrid presented a lower growth. The addition of increasing N doses by application of the urea fertilizer, promoted increments in the growth of the rootstocks, and in the contents of total N. At 120 days after sowing, lemons 'Cravo' presented maximum height of 13.3 cm when fertilized using 1,240 mg/dm³ of N in substrate, whereas the lemon 'Volkameriano' presented maximum height of 12.3 cm when fertilized using 1,417 mg/dm³ of N in substrate. The 'Cleópatra' tangerine presented maximum height of 12.0 cm when fertilized using of 1,170 mg/dm³ of N in substrate, while the tangerine 'Sunki' presented a 10.1 cm height when fertilized using 1,145mg/dm³ of N in substrate, at 120 days after sowing. The hybrid 'Tangelo-Orlando'presented a maximum height of 9.1 cm when a dose of 1,117mg/dm³ of N was applied to substrate.
citrus; nursery; manuring; nutrition; nitrogen
