Autumn Sown Brassica

Looking for quick feed?

Autumn sown brassica and ryegrass provides a quick option for increasing early DM production, whilst reducing feed costs ($/tonne).

Sown at 2 kg/ha with normal rates of ryegrass in late Februaury to mid April, commonly Crusader Italian ryegrass, the hybrid brassica and ryegrass blend can produce considerable extra DM production for an increased sowing cost of approx $20/ha. The extra growth at first grazing provided by the brassica and ryegrass blend when compared with straight ryegrass can be anywhere between 1,500 - 3,000 kg DM/ha, which depends on soil temperature and moisture.

Autumn sown Hunter forage brassica sown at 2 kg/ha with 20 kg/ha Crusader Italian ryegrass. The paddock is ready for grazing 6-8 weeks from sowing.

Aim to sow no more than 6-7 ha/100 cows to Hunter forage brassica and Crusader Italian ryegrass otherwise shading of the ryegrass will occur effecting ryegrass establishment and subsequent grazings. Grazing should commence 5-6 weeks from emergence. Hunter forage brassica's large leaves and prostrate growth can cause shading. If looking for more area sown to brassica and ryegrass sow Winfred forage brassica and Crusader Italian ryegrass for later maturity or stagger sowing date, aiming to sow Hunter 3 to 4 weeks from first sowing. The later sowing will most always result in reduced brassica growth due to lower soil tempertures. Once you reach late April - early May there is little to no gain from sowing brassica with ryegrass.

Winfred forage brassica and Crusader Italian ryegrass autumn sown in March at Cobram in the Goulburn Valley. Photos show pre-grazing mass. The Winfred and Crusader was able to produce an extra 2,110 kg DM/ha when compared with straight Italian ryegrass sown the same day.

This year we will have trials in Gippsland and Goulburn Valley looking at the extra DM produced from Autumn sown Hunter and ryegrass when compared with ryegrass. Stay in touch for the results!

Keep An Eye Out For African Black Beetle

With the autumn approaching it is now time to monitor African Black Beetle (ABB) numbers.

African Black Beetle is a pasture pest found mainly in warmer, high rainfall environments of Australia. Traditionally African Black Beetle has been found around south-western Western Australia and from the coastal south-eastern mainland of NSW around Bega up to South East Queensland (DPI). Their incidence through the North East ranges of Victoria has been a relatively new occurrence, particularly in 2011 where they caused widespread damage to emerging pastures in autumn. Black beetle has however been an issue for East Gippsland for a number of years.

Lifecycle of African Black above highlights the adult and larval stages of the insect pest. Source Dairy NZ.

The damage caused by African Black Beetle depends on whether it is the larval stage (similar appearence to Cockchafer grubs) or adult beetle stage. Generally the larval stage causes issues during summer (December – February) where they chew on the roots of grasses (e.g. perennial ryegrass) restricting root growth and causing plants to be pulled. Damage caused by the adult stage is generally present from late summer and autumn (February – April) where they cause considerable damage to emerging seedlings chewing the tillers around the base of the emerging plant, just above the ground, killing them. While the beetle stage is present though winter and spring they don’t cause considerable damage to pasture during this time.

Adult and Larval stages of African Black Beetle above. Source Dairy NZ.

Damage caused from adult stage of African Black Beetle in the autumn to emerging ryegrass plants. Source Dairy NZ.

Control of African Black Beetle can be acheived by;

• cultivating the larval stage during summer
• using insecticides to control adult beetles in autumn
• using endophytes such as AR37 which have protection against ABB once established.
• using Gaucho treated seed for control of ABB at seedling stage
• using a break crop using a species that larval stage doesn't feed on such as brassica.

Gaucho treating seed can help to reduce the effect adult beetles have on seedlings. Above shows Gaucho treated seed (RHS) vs untreated seed (LHS). Source Dairy NZ.

For more information contact Smyth Seeds on (03) 5762 5288.