EFFECTS OF NITROGEN ON ACCUMULATION AND PARTITIONING OF DRY-MATTER AND NITROGEN OF VEGETABLES .1. BRUSSELS-SPROUTS

Brussels sprouts (Brassica oleracea L. var gemmifera DC) accumulates l arge amounts of nitrogen and the nitrogen harvest index is low. Derail ed information on nitrogen effects on crop development and growth, how ever, is scarce. Therefore, four experiments were carried out in which treatments consisted of different amounts and different dates of appl ication of nitrogen. Dry matter and nitrogen accumulation of stem, api cal bud and groups of leaf blades, petioles and sprouts were measured frequently throughout growth. Total amounts of accumulated dry matter and nitrogen were affected by amount of nitrogen applied and date of a pplication. Sprout growth started halfway the growing period. The fina l harvest index for dry matter ranged from 0.10-0.35 and for nitrogen from 0.20-0.55; both were not significantly affected by treatments in most experiments. Nitrate nitrogen concentrations were only high (maxi mally about 2%) shortly after planting. The total nitrogen concentrati on of leaf blades and petioles increased with increasing leaf number. This increase resulted from a decreasing nitrogen concentration during the leaf's life. The total nitrogen concentration in sprouts changed little with leaf number.