ABSTRACT

Determining the economical dose of nitrogen (N) for colored cotton can increase yield and income of farmers. The experiment was carried out under field conditions at the Experimental Farm of the Universidade Federal Rural do Semi-Árido, in the years 2016 and 2017. The objective was to determine the economical N dose for four colored cotton cultivars. The experimental design was in randomized blocks, with split plots and four repetitions. Five N doses (0, 50, 100, 150 and 200 kg ha^-1) were randomized in the main plots and four colored cotton cultivars (BRS Safira, BRS Rubi, BRS Topázio and BRS Verde) were randomized in the subplots. The characteristics evaluated were seed cotton yield, cotton fiber yield, N concentration in leaf tissue, technical dose and economical dose of N. Higher yield of naturally colored cotton can be obtained using the economical doses of 140 kg ha^-1 N for cultivars BRS Rubi and BRS Verde, 150 kg ha^-1 N for BRS Topázio and 160 kg ha^-1 N for BRS Safira. Highest yield was achieved with the cultivar BRS Topázio and lowest with the cultivar BRS Verde.

Key words:
Gossypium hirsutum L.; cultivars; fiber yield