Brassica : Harvesting the Genome, Diversity and Products
Land use and crop nutrition
In some systems, oilseed crops are grown in rotation with cereals, with added beneficial effects as a soil fumigant. Sustainable yields are dependent upon efficient use of macro- and micro-nutrients. Nitrogen and phosphate limit yield potential, but there is considerable genetic variation for their efficient uptake and utilisation within Brassica crops.
Where Brassica oil crops are mechanically sown and harvested in many regions of the world, labour inputs are relatively low. Brassica vegetable crops are subject to more intensive cultivation, and mechanisation varies region to region and crop to crop. There is increasing pressure on reducing labour inputs associated with crop establishment, crop protection and harvest. In addition, there are requirements to attain sustainable production through reduction in mechanised post-processing and waste. In many parts of the world the majority of losses occur post production, often associated with poorly developed supply chain systems. There are thus important drivers for improved post-harvest keeping quality (especially of vegetables).
There is an increasing amount of quantitative information becoming available on the environmental impact of different crops. The is variation in the amounts of inputs in terms of water and chemical use, as well as in amount of run off pollution in terms of fertliser and pesticide use. For intensive cultivation there are pressures to reduce inputs and pollutants.
There are continuing threats to the production of Brassica crops worldwide, with different pests and diseases having global or regional significance. Major diseases include Leptosphaeria blackleg (esp. on oilseeds), Xanthomonas black rot (on vegetables, clubroot and downy and powdery mildews. Major pests include diamond back moth and cabbage aphid. In some regions (UK, elsewhere) bird and slug damage have major effects on crop establishment, particularly of oilseeds.
3.2.5Effects of climate change
Changes in climate patterns and overall increases in average global temperatures are likely to have profound effects on Brassica production worldwide. In particular, the availability of usable land, water, incidence and changes in pests and diseases and seasonality may have unpredictable knock-on effects. Understanding plant adaptations to changes in the environment, and the availability of robust genetic variation will be essential to underping relevant crop improvement.
Draft White Paper for Multinational Brassica Genome Project (MBGP); 12/01/2006