Cereal growers often wait for a spray failure, or repeated spray failures, before acting on a probable resistance problem.
 

While poor weed control can be caused by other factors such as plant stress, poor application technique or late spray timing, growers (and agronomists) often have a ‘gut feel’ if resistance is an issue. Particularly if they have been growing cereals in the same paddock for a number of years!
 

To help growers confirm if they have a resistance problem in cereals, Syngenta has developed the Resistance In Season Quick (RISQ) Test for detecting herbicide resistance for grass weeds susceptible to Twinax.
 

“The Syngenta RISQ Test is a fast and costeffective way of testing for resistance prior to herbicide application, allowing growers and agronomists to make informed decisions on herbicide choice,” explains Syngenta mid Canterbury territory manager Sam Livesey.
 

The Syngenta RISQ Test requires a sample of 100 seedlings at the 1-3 leaf growth stage. Seedlings must be dug out carefully and excess soil removed without damaging the seedling roots or leaves.
 

The seedlings are couriered to the laboratory in Christchurch and the results are available in just 14 to 21 days.
 

“This is much faster than traditional resistance test methods that can take several weeks or even months to get a result, which

is too late for growers to make in season decisions,” says Sam Livesey.
 

At this stage, the Syngenta RISQ Test can test ryegrass, phalaris and wild oats for resistance to Twinax, a Group A ‘den’ herbicide.
 

However, Syngenta may extend the RISQ Test to include other Group A Herbicides and Group B (sulfonylureas) in the future.
 

This would allow growers to consider what herbicide options are still effective for grass weed control in a particular paddock.
 

The cost of the Syngenta RISQ Test to growers is $250.00 plus GST.
 

The test is available through Syngenta resellers who have agronomy/field staff available to conduct the test.
 

The cost covers the time spent by the reseller agronomist in collecting seedlings, courier costs, testing, the test report, and agronomic advice.
 

Sam Livesey says herbicide resistance testing should be seen as a regular part of management along with soil testing.
 

Growers should consider RISQ testing paddocks this season where wild oats or grass weeds survived herbicide application last

season, or for high risk paddocks based on previous cropping history.
 

For more detail phone Syngenta, 0800 333 336.