II.3. BRASSICA CROPS (BRASSICA SPP.) – 183
Figure 3.30. Major production region (striped area) of oilseed mustard (B. juncea)
and toria (B. rapa) on the Indian sub-continentSource: Courtesy R.K. Downey
Chinese cultivation and management^3
China is the world’s largest producer of Brassica oilseed crops, annually producing
some 11.5 million tonnes. Species contributing to this output include winter and spring
B. napus, B. juncea and both winter and spring forms of B. rapa. Production is primarily
from B. napus (representing 95% of the total), but both B. juncea (4%) and B. rapa (1%)
oilseed crops are also grown at various concentration in the different provinces.
B. napus is grown throughout the country with the winter form dominating in the
southern provinces and the spring form in the north.
The provinces along the Yangtze River provide the bulk of China’s production.
The level of winter hardiness required is not great. Indeed, Canadian and European
varieties of the spring form have successfully survived the winters in the Chinese winter-
growing region.
The spring-sown crops (B. napus, B. juncea and B. rapa) are sown in May, flower in
June or early July and are harvested in September. The growing cycle for B. napus takes
about 120 days. In the southern portion of the spring-growing area, half a season may be
used to grow a forage or vegetable in conjunction with B. rapa. Because of the small field
sizes, most are sown by hand or walking plough, although some large fields are
mechanically sown. In the winter rape areas, the seed is sown into small seedling beds in
September and the seedlings later transplanted into the production fields in mid- to late
September. Flowering takes place in late March and harvest is in May. The total
production cycle is about 220 days. The rotation in the triple cropping winter rape area is
either rape-rice-rice or rape-maize-potato and in the double cropping regions rape-cotton
or rape-rice.
Soil fertility is a limiting factor in production, with the area devoted to winter rape
being particularly deficient in phosphorous. While all soils require nitorgen, phosphorous