In Itatiba, São Paulo state, Brazil, during the period between March and July of 2007, an experiment was carried out aiming to appraise the effect of doses of nitrogen and potassium (105-105, 157.5-157.5, 210-210, 262.5-262.5 and 315-315 kg ha-1 N and K2O) and spacing between plants (0.2, 0.3, 0.4 and 0.5 m) upon the yield of broccoli and their classification. The experimental design was carried out in a randomized block, with the treatments in a 5 x 4 factorial scheme and three replications. Rows of plants were 0.8 m apart. The following characteristics were evaluated: foliar content of nitrogen (N) and potassium (K), head yield (HY), florets yield (FY), industrial yield (IY) and classification of florets based on length: FY5 (<5 cm); FY57 (>5 and <7 cm); FY79 (>7 and <9 cm) and FY9 (>9 cm). The largest spacing between plants provided the highest N, but HY and FY were reduced. The NK dose and spacing between plants did not influence significantly the level of K and IY. The maximal HY (22.08 t ha-1) and FY (17.09 t ha-1) were obtained with 0.20 m between plants and 150% NK dose (315 kg ha-1 of N and K2O). The higher percentage of florets in FY5 was obtained with smaller spacing between plants and NK dose and spacing did not influence significantly the percentage of florets with lengths greater than 7 cm.
Brassica oleracea var. italica; nitrogen; potassium; plant population; industrial yield
