Cauliflower and broccoli productivity as influenced by phosphorus fertilizer doses in a P-rich soil

Abstract

Although being little accumulated by cauliflower and broccoli plants, phosphorus (P) is one of the most important nutrients influencing growth and productivity of these species. The information in the literature concerning doses of P demanded by those species is scarce and conflicting. Therefore, two experiments were conducted in the field, in 2010, in Jaboticabal, Brazil, aiming to evaluate five P doses (0, 80, 160, 240, and 320 kg ha-1 P2O5) on cauliflower and broccoli. For each experiment, brassica, the experimental design was a randomized complete block with four replications. At the beginning inflorescence stage, the P level in the leaves was verified to be significantly influenced by P dose only in cauliflower plants. Cauliflower (35 970 kg ha-1) and broccoli (11 425 kg ha-1) maxima productivities resulted from the respective doses of 245 and 320 kg ha-1 P2O5. In both experiments, after harvest of cauliflower and broccoli, significant effects of P doses were observed in soil P content, mass and diameter of the inflorescence, and productivity. The broccoli and cauliflower crops respond positively to P doses even in P-rich soils and that they demand different amounts of phosphorus to reach maximum productivity and inflorescence diameter and mass.