Variety selection

The ACRCP encourages growers to phase out susceptible and very susceptible varieties from their rotation where possible but if these cultivars are grown, then farmers need a management plan ready in advance in case of a rust outbreak. A grower’s individual disease management plan must take into account their property’s level of risk, including rainfall, location and variety selection.

To help make a decision on which variety to grow, click on your state below for relevant ratings information.

State ratings

Further information to help make variety selection decisions can be found on the NVT web site.  This site provides access to independent results on the performance of recently released grain and field crop varieties from trials conducted across Australia.

Explanation for Resistance Classification

Australian wheat cultivars are assessed annually for their rating to each of the three rusts. The disease rating (explained below) provides a guide as to the relative potential yield loss that a variety may suffer in seasons suitable for the disease. Selecting cultivars with more resistance will reduce the potential losses that a grower may incur and reduce the level of additional management that will be required.

Classification Description
R The disease will not multiply or cause any damage on this variety. This rating is only used where the variety also has seedling resistance.
MR The disease may be visible and multiply but no significant economic losses will occur. This rating signifies strong adult plant resistance.
MS The disease may cause damage but this is unlikely to be more than around 15% except in very severe situations.
S The disease can be severe on this variety and losses of 15-50% can occur.
VS Where a disease is a problem this variety should not be grown. Losses greater than 50% are possible and the variety may create significant problems to other growers.

 

This classification based on yield loss is only a general guide and is less applicable for the minor diseases such as common root rot, or for the leaf diseases in lower rainfall areas, where losses are rarely severe.

Example – stripe rust yield losses

As an example on the relative losses that can occur data collected by DPI Victoria has found that a stripe rust outbreak in MS-S varieties could cause a 26% yield loss compared with growing a rust resistant variety which has no yield loss.

Table: Average yield losses in the presence of stripe rust in varieties with different stripe rust ratings in south-eastern Australia during 2005

Rating *

Relative yield loss (%)**

R

0

MR

3

MR-MS

17

MS

20

MS-S

26

S

65

VS

70

* Ratings are based on estimates of potential yield loss R = 0%, MR <5%, MS <15%, S < 30%, VS > 30%

Rating abbreviations:  R = Resistant, MR = Moderately Resistant, MS = Moderately Susceptible, S = Susceptible, VS = Very Susceptible.

** These figures are indicative only.