Abstract
The oil and protein concentration response of canola (Brassica napus L.) to application of nitrogen (N), applied as urea (46%), was measured in 210 field plots done in 1994 and 1995 in south‐western Australia (WA). The canola was grown on a range of soil types deficient in N for maximum seed production. The sites were sown in late May to early June. The concentration of oil in the canola seed decreased concomitantly with an increase in protein. In all experiments, in both years, there was no relationship between the seed yield and the resultant oil or protein concentration. The addition of the oil plus protein concentration in the canola seed was an approximately constant 62% in the both years.