- Seed treatments (pickles) effectively control bunt, smut and powdery mildew. Ensure they are applied every season as a small cost up front will ensure grain is accepted on delivery.
- Seed treatments are becoming more important for the control of foliar diseases like the net blotches in barley and rusts in wheat.
- Keep seed treatment rates up – particularly for Systiva® (fluxapyroxad) as low rates may not control powdery mildew adequately.
- Ensure that the product being used is registered for the disease being targeted. Use fungicides as part of an integrated package of control measures that include resistant varieties and alternative active ingredients.
- Be aware of possible emergence problems which may be caused by certain treatments, and poor seed quality.
Despite a couple of dry seasons and a bit less money in the bank, growers should avoid cutting costs by avoiding cereal seed treatments. Using a cheaper seed treatment that controls bunt and smut alone can reduce costs, however, growers need to plan for what other diseases they need to be controlling. Foliar diseases such as powdery mildew and root diseases such as rhizoctonia should also be considered when selecting a product. In the Southern Region all growers should be treating barley for powdery mildew. Consult your relevant regions seed treatment guide for further regionally specific advice (see Choosing the right seed treatment).
Reduced stubble breakdown, in some areas, as a result of dry conditions means inoculum will be carried over from the previous two seasons. Given the right conditions, the incidence of stubble-borne diseases, could increase rapidly, especially if wheat or barley are sown back onto respective stubble.
Many growers have already ordered the recently released Systiva® (fluxapyroxad) for control of barley net blotches, powdery mildew, leaf rust, scald and smuts. However, growers must remain cautious as, despite the effectiveness of this new treatment in combatting the net blotches, rates need to be kept up for effective suppression of powdery mildew. If Systiva® (fluxapyroxad) is used alone on very susceptible varieties it will hasten the development of fungicide resistance. Be sure to rotate this product with other (azole) products registered for net blotch control.
Why do we need to treat seed?
The primary reason for treating seed is to combat seed-borne diseases like bunt, smut and powdery mildew in barley. The secondary reason is the suppression of fungal root rots (Rhizoctonia, take-all) and other foliar diseases.
There are two seed treatment options available – seed dressings and in-furrow fungicides. If using in-furrow fungicides growers still need to use a seed dressing to control bunt and smut.
The following resources are available to assist growers in choosing the right mix of treatments for their situation.
Southern Region: SA Cereal Seed Treatments 2016
Western Region: Seed dressing and in-furrow fungicides for cereals in WA
Caution should be taken in using seed treatments as some seed dressings, for example, fluquinconazole, flutriafol or triadimenol have been shown to reduce coleoptile length under certain conditions. This can result in poor emergence especially in short coleoptile varieties.
Always check the fungicide and herbicide label for possible emergence problems.
Other factors that can cause poor seedling emergence include deep sowing, surface crusting, low soil temperatures and the use of Group D dinotroaniline herbicides, for example, trifluralin, pendimethalin, and oryzalin.
Seed dressings should not be used on weather damaged, pinched or seed with poor viability. Use a germination/vigour test to ensure seed is a high standard.
Various seed testing services are available for variety identification, seed quality, and germination testing. Seed testing services are listed below.
AGWEST Plant Laboratories – Germination and seed variety identification
Agrifood Technology – Grain quality testing
PIRSA Seed Services Australia – Seed purity and germination
How to conduct a germination test – Birchip Cropping Group