166 – II.3. BRASSICA CROPS (BRASSICA SPP.)
B. oleracea var. gemmifera, Brussels sprouts
B. oleracea var. gemmifera plants are cool season biennials with simple erect stems
up to 1 metre tall, bearing round to heart-shaped simple leaves with lengthy petioles.
The leaves are glabrous with the colour varying from light to deep greyish-green.
In the first year, auxiliary buds or sprouts are borne beneath the leaves on an elongated
stem (Figure 3.17). The buds are modified leaves that form small heads up to 30 mm
in diameter. Following vernalization, a seed head is produced from which a flower stalk
emerges bearing perfect, self-incompatible flowers on terminal racemes. The seeds,
weighing about 2.8 g/1 000, are borne in typical, two locule siliques.
Figure 3.17. B. oleracea var. gemmifera, Brussels sprouts
Source: Courtesy Limagrain.
B. oleracea var. alboglabra, Chinese kale
The var. alboglabra is widely grown throughout south-east Asia as a leaf and stem
vegetable. The perennial plants are grown as annuals, producing dull or glossy thick
green, glaucous, elliptic leaves about 25 cm long. The plants commonly called Chinese
kale and kailan attain a height of up to 40 cm in the vegetative stage and 1-2 metres at the
end of flowering. Upper stem leaves are oblong, petioled or non-clasping. The white
flowered inflorescences develop siliques 5-8 cm long (Herklots, 1972).
Brassica napus
B. napus var. napobrassica, rutabaga or Swede
B. napus var. napobrassica, the common rutabaga or Swede, is a biennial with similar
characteristics to the turnip. The bulbous root develops from the hypocotyl in the first
year of growth (Figure 3.18). The surface of the root may be purple, white or yellow with
the inner content solid yellow or white fleshed. The thick, smooth, dark green leaves
emerge from the crown or neck of the root to form a ground covering rosette that shades
out competing weeds. The presence of a root crown or neck distinguishes rutabagas from
turnips. Early in the second year the flower stalk bolts from the root crown and the
self-compatible flowers produce short beaked siliques on short pedicels containing
two rows of round black seeds. Rutabagas are used for human consumption and for late
fall cattle grazing.
