Choosing a seed treatment starts with knowing your seed quality and your seeding conditions.
Good germination and vigour are still the number one priority. Seed treatments can provide protection from some diseases and insects but do not improve the quality of the seed. In other words, seed treatments do not make dead seed germinate and won’t improve the quality of bad seed.
Deciding whether to use a seed treatment or not is the first step. Some conditions where seed treatments have been shown to be beneficial are: seeding early into cold soils, high level of seed borne disease, seed with mechanical damage such as cracking, and seeding into fields with seedling disease issues from previous years or potential insect problems.
If you have good quality seed and are seeding into warm soils with no expected pathogen or insect pressure, then you may not see a benefit from seed treatment.
It is extremely important to know what level of disease is in the seed you intend to plant. If you’re planning on using common or bin-run seed, a seed test is going to be a valuable piece of information. This information is even more important this year with the high level of diseased seed across the province.
For pedigreed seed you will be provided this information. Saskatchewan Ministry of Agriculture has guidelines for seed borne disease for both cereals and pulse crops. These guidelines will make recommendations whether to use seed treatments or source different seed based on disease levels in your intended seed lot.
With fusarium graminearum for example; with any seed over five per cent, it is recommended to find another seed source. If another seed source is not available, a seed treatment would be strongly recommended.
With total fusarium spp.you can get away with higher levels but it is still recommended to use a seed treatment once levels get over five per cent As total fusarium spp levels approach 10 per cent or higher, consider another seed source.
Once the decision to use a seed treatment has been made, then you need to choose which one is best. For this you will need to know what pathogens or insects you need protection against.
With soil borne pathogens that cause seed and seedling diseases you may not know which pathogen will be present and most damaging each year.
The pathogens involved can include fusarium spp., pythium, rhizoctonia, aphanomyces as well as cochliobolus sativus. Fusariumcontinues to be a challenge across Saskatchewan, making it a safe bet to assume is present in the soil.
Pythiumandaphanomycesare particularly well adapted to wet, waterlogged soils and are less affected by temperature while rhizoctonia thrives under cool, moist early-season conditions. These are just general guidelines as it is difficult to predict which organism may be more prevalent in your soils and most seed treatments can provide protection for most of the organisms mentioned.
Other diseases that can be controlled by seed treatments include seed-borne ascochyta in pulses, smut, bunt and seed-borne septoria in cereals, as well as seed-borne blackleg and alternaria in oilseeds.
Knowing your field history and seed disease levels will help with the decision whether protection from one of these diseases is warranted.
For insect protection there are many product options that can provide protection from wireworms in cereals, flea beetles in pulses and cutworms in canola and mustard. If you had problems with any early-season insect in the past or suspect high pressure this year, then you may want to opt for a seed treatment with the added protection.
There are a lot of products on the market so the choice can be difficult. It’s important to use a product that is registered for control of the disease or insect you are interested in.
There are a couple other factors to consider as well, the first being application method. Some products are only available to commercial treaters, while others have on-farm applications. No matter which you choose, all products need to be applied properly assuring good coverage of each and every seed. Ease of application of the product is also worth considering.
Seed treatments are a good choice if you are seeding early into cool, wet soils. It is added insurance to get your crop off to a healthy start. Remember that seed treatments are only effective if applied at the recommended rates and with good coverage. They typically provide protection for up to 21 to 28 days after seeding, depending on conditions, so monitoring your crop is still important.