EFFECT OF NITROGEN-FERTILIZATION ON HEAD SIZE, VITAMIN-C CONTENT AND STORAGE LIFE OF BROCCOLI (BRASSICA-OLERACEA VAR ITALICA)

Broccoli quality in British Columbia can vary with season and with the farm site on which it is grown. One major management difference between farms is nitrogen fertilization rate. This work was conducted to determine the effect of nitrogen fertilization (0, 125, 250, 375, 500 and 625 kg N ha(-1)) and growing season (three plantings in 2 consecutive years) on vitamin C content, head size and storability of broccoli (Brassica oleracea var. Italica, 'Emperor'). The climatic conditions during crop growth and development had a greater overall effect on vitamin C content, head diameter and head weight than nitrogen fertilization. Weight and vitamin C losses during storage in the first year were not affected by nitrogen fertilization rates. Moderate nitrogen application rates of 125 and 250 kg N ha(-1) in all three plantings produced a head size considered optimal for marketing.