Brassica campestris var. rapa
Vigourous summer growing fodder crop with excellent feeding value; high leaf to stem ratio.
Sensitive to several common insect pests.
Leafy, plant 0.6-1.2 m tall; swollen stem forms an edible bulb at base; deep tap root. Some varieties regrow to allow 1-3 repeat grazings.
Varies with variety from large to small and from bulbs that sit well into the ground (suited to storing for late grazing) to those that are more accessible early/mostly out of the ground.
Large, flat leaves, 30-50 cm long and 20-40 cm) wide; yellow, cross-shaped flowers with four petals; and all produce sickle shaped pods containing tiny round seeds.
Yellow, cross-shaped flowers with four petals; produce sickle shaped pods.
Pods contain tiny round seeds.
Pasture type and use
Sown in spring adjacent to a run-off pasture to provide summer grazing in ~3 months time. Some varieties can be managed to provide bulbs that will allow grazing through winter; some can provide leaf for early grazing and their bulbs can be grazed later.
Often used as a pioneer crop or to provide weed control and soil preparation prior to renovating with perennial pasture. Useful as a break crop after cereal.
Where it grows
> 550 mm or irrigation.
Tolerates a broad pH range. Some varieties are unsuited to soil with low fertility. Ensure Mo and B not deficient.
Some varieties are well able to withstand heavy frost and retain leaf.
Legumes: white clover, red clover.
Sowing/planting rates as single species
0.5 – 2 kg/ha. A low rate encourages good bulb development and enables delayed grazing into winter. A high rate aids rapid early yield and a high leaf:bulb ratio. Sow shallow (5-10 mm) in a finely worked firm, moist seedbed, cover with roller/mesh. Only suitable for direct-drilling in friable soil.
Sowing/planting rates in mixtures
From August through spring.
Sow with ~20 kg P/ha as triple super or MAP/DAP. Ensure molybdenum and boron adequate. Molybdenum coated seed is available.
Nitrogen (50 kg N/ha) maybe applied at 4 weeks.
Do not Graze when immature. Where yield is high, strip-graze dairy cattle along a long front – to minimize trampling losses. A back fence may maximise regrowth. Use a maximum 33% in the diet of dairy cows – 100% OK for lambs. Beef cattle OK up to 70%. Allow access to pasture/stubble, hay/silage for fibre.
Not as vulnerable as rape. Red-legged earth mite, slugs, Aphis, cabbage moth, cabbage white butterfly, diamond black moth, cutworms, lucerne flea, wingless grasshoppers and leafminers. Insecticide coated seed is available to aid establishment.
Excellent – low fibre is associated with a high rate of digestion which facilitates a high intake. ME approx 12 MJ/kg DM.
Up to 16 t DM/ha where moisture is available and soil fertility is high.
Vaccinate and drench before grazing stock on Brassica. Monitor stock frequently. Red water/kale anaemia can occur especially where soil sulphur levels are high. Scouring, and nitrate poisoning (especially if molybdenum is deficient and/or if overcast conditions prevail). Avoid sudden and unrestricted access; do not provide Brassica crops as the sole ration straight off scarce/low quality pasture. Provide good source of water. Begin 1-2 hr access daily and take 7-10 days before reach maximum allowance.
|Early||Vertus 69||Stephen Pasture Seeds|
Seed Force NZ
|Marco (4n)||Stephen Pasture Seeds|
|York Globe||AusWest Seeds|
|New York||PGG Seeds|
|Barabas (4n)||AusWest Seeds|
|Rival||Stephen Pasture Seeds
|Late||Australian Purple Top||PGG Seeds|
|Mammoth Purple Top||Stephen Pasture Seeds|
|Green Globe||Wrightson Seeds|
|White Star||Seed Force NZ|
(4n) = tetraploid
Author and date