II.3. BRASSICA CROPS (BRASSICA SPP.) – 177
Feral populations in natural habitats
In natural (undisturbed) ecosystems, B. napus is not considered to be invasive or even
a significant component of any natural plant community (AAFC, 1994; Warwick, Beckie
and Small, 1999; Beckie, Hall and Warwick, 2001; Dignam, 2001).Production and agronomy of Brassica oilseed crops
The world demand for edible oils and more recently for biodiesel has led to a rapid
growth in the production of most oilseeds, with total seed oil produced increasing by
about 4% each year. The percentage growth in the world Brassica seed oil production
increased some 60% between 1996-09 and 2006-10 (Table 3.1). The locations of the
major rapeseed/mustard producing regions over the two decades 1995-2014 are shown in
Table 3.4. The expanded Brassica oilseed production has resulted from both an increase
in the area sown globally, as well as the yield per unit area that has increased in most
regions (Table 3.4).Table 3.4. Area harvested, production and yield by major Brassica oilseed producing countries,
averages 1995-99 to 2010-14Producing
countryArea harvested (‘000 ha) Production (‘000 tonnes) Seed yield (kg/ha)
1995-99 2000-04 2005-09 2010-14^3 1995-99 2000-04 2005-09 2010-14^3 1995-99 2000- 04 2005- 09 2010-14^3
E.U.^1 3 944 4 255 5 407 6 693 11 038 12 221 18 108 20 865 2 786 2 862 3 082 3 120
Canada 4 917 4 366 5 322 7 757 6 866 6 237 10 510 15 171 1 398 1 415 1 790 1 954
China (People’s
Republic of) 6 708 7 244 6 740 7 244 9 391 11 573 12 070 13 315 1 399 1 597 1 842 1 836
India 6 541 5 110 7 280 6 303 5 756 5 045 7 239 7 417 884 982 1 079 1 178
Australia^2 929 1 335 913 2 425 1 230 1 529 1 395 3 133 1 370 1 146 1 084 1 277
United States 292 497 452 568 443 762 665 1 009 1 505 1 555 1 635 1 780Notes: 1. E.U. = Total production of the 27 (28 from 2013) member states of the European Union. 2. Extreme drought greatly
reduced Australian production and seed yield in the 2005-09 period. 3. Columns added in January 2016.
Source: FAOSTAT.
Cultivation and management of oilseed crops
The small seeds of the Brassica oilseed crops require that the seed be sown at shallow
depths, 2-3 cm below the soil surface, into a firm, moist seedbed. Under favourable
growing conditions the seedlings emerge within four to five days of sowing. Cotyledon
expansion is quickly followed by the formation of a rosette of seven to eight true leaves
from which the flowering stalk bolts. The length of time the crop remains in the rosette
stage can vary from less than 30 days to more than 210 days depending on climatic
conditions and the species and form grown. The complete growth cycle may be as short
as 70 days (B. rapa) or as long as 380 days for winter B. napus varieties in China
(Sun et al., 1991).
Although the Brassica oilseed crops prefer a deep loam soil, it does well when sown
in a wide range of soil types and conditions and can tolerate a pH range from 5.5 to 8.
Compared to most other grain crops, Brassica oilseed crops require greater nutrient inputs
to achieve high yields. Generally speaking, they need about 25% more nitrogen,
phosphorus and potassium and up to 5 times more sulphur than a wheat crop. Harvested
seed should be stored at no more than 9% moisture when cooled to 10ºC to prevent
deterioration due to fungal and/or insect activity. The usual rotation is as a break crop