Safeguard is a new grazing ryegrass with outstanding resistance to the nematode involved in causing annual ryegrass toxicity. Therefore, livestock grazing Safeguard pasture have a significantly reduced risk of developing annual ryegrass toxicity.

Introduction

Annual ryegrass toxicity (ARGT) is a common problem for livestock producers throughout much of the agricultural area in Western Australia and South Australia. Outbreaks of ARGT now occur in the high rainfall zones.

Safeguard is bred with a high frequency of the genes resistant to the nematode (Anguina funesta) involved in causing ARGT. This will result in very little of the toxin producing bacterium (Rathayibacter toxicus) being carried to the seed-head. Thus toxin production and the risk of ARGT will be significantly reduced.

This management guide indicates the practices that will most likely result in good establishment of Safeguard pasture and minimise the risk of ARGT. Consideration of the management program requires medium term (2-3 years) planning to ensure the benefits are obtained.

Before sowing Safeguard: paddock preparation

  1. Selection of paddocks to be treated as Safeguard ARGT resistant paddocks will depend on your situation and requirements for feed through a risk period. Importantly, these paddocks should be developed as specialist, high producing areas (NOT sacrifice paddocks, or the worst paddocks).
  2. Defining the areas required will depend highly on the numbers of stock you are carrying and the time frame required.
  3. Once paddock selection has been undertaken, a program to reduce the likelihood of grass contamination and weed burden, should be implemented. This process requires some good forward planning and should be practiced to eliminate existing banks of potentially harmful Wimmera seed.

Reduce seed reserves (the year before sowing Safeguard)

In a crop:

  • Use a selective herbicide.
  • If the ryegrass is herbicide resistant, cut the crop for hay no later than the start of flowering of the ryegrass and then graze heavily and or spray the regrowth with a non-selective herbicide.

In pasture:

  • Spray-top with a non-selective herbicide, slash or cut for hay no later than the start of flowering of the ryegrass, then graze heavily to prevent viable seeds being produced.

In the year of sowing Safeguard

  1. Control the seedlings with a non-selective herbicide. If the background population of annual ryegrass is high, the paddock may need to be cultivated several times to kill off germinating seedlings and reduce seed reserves. This technique will help to ensure that competition from existing Wimmera ryegrass and from other weeds is low. Note: If you are confident of low background ryegrass levels (dormant seed) do not cultivate, and plant using a minimum soil disturbance seeder to minimise germination of dormant Wimmera seeds.
  2. Cultivate the paddock after the autumn break to stimulate germination of the local ryegrass seed reserves.

Seeding for success

Only use certified Safeguard seed. When you buy certified Safeguard you can be assured your ryegrass is nematode resistant. Non-certified seed is likely to be nematode susceptible and it may be herbicide resistant. The minimum sowing rate for Safeguard is 8kg/hectare (7lbs/acre). This should produce enough feed to graze the paddock in the first year and also enough seed for establishment of Safeguard as a self seeding annual.

Seed should not be sown deep: drop the seed on the surface and use harrows to cover lightly with soil or preferably sod seed with a triple disk into non-cultivated soil. Ensure there is adequate fertiliser applied at sowing. Get a soil test if you are uncertain.

Leave a test strip

It is important to check that local ryegrass levels are low, as it is not possible to identify local ryegrass in a pasture sown to Safeguard. Leave an unsown strip at least two metres wide and five metres long, well inside the paddock. Two areas of unsown strips are preferable and it is important not to travel over the unsown strip with the drill; travel around it. If a large infestation of the local ryegrass appears in this strip, and the paddock has a history of ARGT, treat it as potentially hazardous for livestock.

As a precaution, stop seed set and commence regular (daily) stock inspections in mid-September and continue throughout the summer. Remove stock from the paddock if they show any signs of poisoning.

Set plenty of seed in the first year

The aim in the first year should be to achieve a heavy seed set; if you are confident Safeguard is the dominant grass. This should allow Safeguard seed to greatly outnumber local ryegrass seed reserves. Safeguard should produce more feed than Wimmera ryegrass. It is likely to produce more leaf and hold its leaf later in the season than Wimmera. This feature may cause it to flower later in certain seasonal conditions. It is therefore important to keep the paddock tightly grazed until mid September then take the livestock out to allow all plants to go to seed simultaneously.

Plan to remove or reduce stock numbers from mid September as Safeguard normally runs to head in early October depending on the area and seasonal conditions. After seed set and when the pasture has fully dried off, stock can be returned to graze on remaining plant residues. Excess ground cover in the following autumn may inhibit Safeguard germination. Following a break in the season, Safeguard should be the dominant pasture grass. If the paddock has a history of ARGT, it is recommended that the mature ryegrass be tested to confirm it is safe to graze. It maybe difficult to assess the relative proportions of Safeguard and Wimmera ryegrass in regenerated pastures, so it is recommended the paddock is tested in subsequent years to confirm that the bacterium is under control.

Grazing management

At seedling emergence ensure that the area sown is checked for insect infestation. If Safeguard is sown as part of a mixture with pasture legumes Red Legged Earthmite populations can increase rapidly and some damage can occur to grasses as well as legumes. It is advised to take precautions by applying approved insecticides at the first sign of plant emergence.

At approximately six weeks or once the plants cannot be easily pulled, lightly graze the area. This can be best managed with younger or lighter beef cattle or sheep and will increase plant tillering. Rotational grazing or controlled grazing should be implemented, grazing the pasture when between 10-15cm high, closing after grazing, at no lower than 3cm, until the area is due for the next grazing.

Consult your local agronomist for further advice if required.