Cell size, transplant age and cultivars effects on timing field production of broccoli (Brassica oleracea var. italica Plenck) for processing

Three cultivars of broccoli were seeded in three containers with cell size ranging from 4.78 to 39.72 cm3 and at density of 1611 to 498 plants-m-2. The aim of the study was to determine the effects of container size, age of seedlings (optimal, 7 and 14 days older) and time of harvest, in order to produce heads in December and January because of the demands for continuity of supply from factories. Age of seedlings did not influence the marketable yield of central heads (CH); older seedlings reduced hollow stem incidence and delayed maturity (days from sowing to first harvest) by 17 days. 'Gran Vert' was less productive and showed a lower incidence of hollow stem. First harvest for 'ML 145' happened at end of February while 'Gran Vert' began to produce on late November and 'XPH 4142' on mid December. When container cell size was less than 20.20 cm3 the yield of CH and lateral head was lower. Earliness was affected by container size and age of transplant and the cultivars showed a different behaviour. The goal to produce heads in December and January was achieved.