Fast growing types (e.g. cauliflower and broccoli) require a high nitrogen supply as they have high nitrogen uptake rates and a high nitrogen requirement, particularly during early growth
Vegetable brassica earliness
Crop Nutrition and Vegetable Brassica Earliness
Nitrogen
Slower developing types (e.g. cabbages) – particularly those growing at lower temperatures and lower radiation conditions – take longer to utilize the N needed for high yields
By ensuring a good supply to the outer leaves, they will develop strongly and support later growth by providing assimilates and also redistributing nitrogen needed for high brassica yields. Failure to get nitrogen into these leaves by using inadequate low rates in early fertilizer applications will result in lower brassica yields. Later applications cannot make up for this.
Potassium
Potassium rates of 225 kg/ha and above produce responses on high yielding sites, increasing both plant biomass and resultant head weight and yield.