Management

New tool for weed control in forage brassicas

By Dairy News

Many regions in eastern Australia are suffering from the effects of below average rainfall and this is causing a rapid decline in the availability — with a corresponding sharp rise in price — of feed, which many dairy farmers rely on to nourish their stock over the summer and autumn months.

In the absence of readily available and moderately priced feed from off-farm sources, farmers this spring may want to give serious consideration to sowing increased areas of summer forage crops.

Many farmers have been experimenting with various summer forage options for a number of years and the more successful have incorporated one or more of forage rape, turnips, swedes, maize and sugar beet into their farm plans.

To successfully grow these feed crops, a number of factors must be considered, including:

  • Will there be enough moisture at crop establishment to get the crops up and growing as quickly as possible?
  • What is the best species mix to maximise productivity?
  • Can the weeds and pests be successfully controlled in these mixes?
  • What is the cost benefit of growing your own feed versus buying in feed from another farm?
  • What will this paddock be used for in the following rotation?

Grain and hay prices are likely to hit record levels this summer so buying in feed becomes less attractive to those farmers with the ability to establish their own summer forage crops.

Maize is a great option for growers with ample water supplies and irrigation capability but it often struggles in many of the dry, hot areas of southern Australia to give long-term feed security.

Swedes, turnips and rape forage brassicas could be a very attractive feed option for many farmers this summer. They are generally a fast growing and a low cost crop which provide a nutritionally balanced and easy to digest food source, providing your stock with a vital source of energy.

Forage brassicas are high in protein, with crude protein content of leaves ranging from 15 to 25 per cent. This can produce excellent livestock weight gains of up to 1.2 kg/day for growing cattle.

In addition to providing a viable source of nutrition for livestock, forage brassicas also form a useful part of a pasture/whole farm improvement program by providing a ‘break’ in the cycle for weeds and diseases, leaving paddocks in ideal condition for sowing new pastures or other crops.

Many farmers moved away from sowing forage brassicas over the past decade due to their inability to control broadleaf weeds and insect problems. Weeds can severely depress fodder crop yield and, in particularly bad situations, livestock will actively avoid feeding within the crop due to weed presence

ForageMax is a unique herbicide solution for in-crop broadleaf weed control in forage brassicas. It maximises the grazing potential of rape and turnips by controlling key problem weeds such as fat-hen, amaranthus (Prince of Wales feather), capeweed, cleavers, deadnettle, fumitory, marshmallow and thistles, allowing crops to flourish.

In the past, these forage crops have often been overrun by weeds therefore reducing the number of grazing events, the overall feed value of the crop and causing ongoing weed problems in following years.

Use of ForageMax consistently increases brassica dry matter (DM) production.

Scott Travers, an agronomist with MG Trading based at Yarram, arranged a recent demonstration on a farm at Calrossie, Gippsland where the dominant weeds were fat-hen, Prince of Wales feather (amaranthus) and stinging nettles.

Where ForageMax was applied, the weeds were completely removed.

“Everyone who saw the site or photos from the paddock (were) pleased with the results. Weed control was really impressive,” Mr Travers said.

ForageMax is best applied early to forage brassica crops to target weeds before they begin to compete for nutrients, water and space.

It works most effectively on small, actively growing weeds that are not stressed by drought, frost, insect or disease pressure.

ForageMax is rain-fast within three hours, has a short grazing withholding period of only 14 days and can be tank-mixed with insecticides and other agricultural inputs. It must be tank mixed with Uptake Spray Oil to ensure optimal performance.

At a turnip demonstration site in southern Australia, the yield from the crop where weeds were controlled with ForageMax reached 10.5 tonne DM/ha. The yield from the untreated portion of the crop was just 3 tonne DM/ha.

Thus at an approximate cost of $50/ha for the herbicide treatment this represents a very high return on investment in terms of available feed, particularly when compared to the cost of buying in hay or grain at current prices.